1. In Colorado, we have average summer temperatures that exceed 86 degrees Fahrenheit.  Knowing this, is there ever a time when Section 310.12 would be permitted for sizing service or feeder conductors supplying a dwelling?

Answer: Maybe, it depends on how much of the “run” is outside exposed to the high ambient ​
References: 310.12, 310.14, 310.15, Table 310.15(1)(1) and Table 310.16​

Table 310.12 is permitted to be used if no adjustment or correction factors must be applied. Table 310.16 and note 1 at the bottom of the table which says to see 310.15(B) when the ambient temperature is other than 30C or 86F​.

310.14(A)(2) exception – if different ampacities apply to portions of a circuit, the higher ampacity shall be permitted to be used if the total portions of the circuit with lower ampacity do not exceed the lesser 10’ or 10% of the total circuit length​
​Use the ASHRE Handbook for the ambient temperature of your location​ OR find a Table of temperatures for cities in the states at Copper Development Association.

Determine the ambient temperature for where the conductors are installed: ​
are they all exposed (outside) on the surface of the dwelling? Are they underground? Are they a mix of inside the walls of the structure and exposed? Determine if the exception can be applied or not. ​
​You will need to know a few things to properly size your service conductors in an ambient temperature of other than 30C or 86F using Table 310.15(1)(1)

What is the calculated load of the dwelling? – the conductors must carry this

after any corrections or adjustments have been made.​

Select a wire to serve that load out of the 75 Degree Column of 310.16 per

110.14(C)(1)​

Apply the applicable correction factor from Table 310.15(B)(1)(1) based on

the ASHRE ambient value, if needed, increase the size of the conductors until

they can carry the calculated load. ​

(You should be using a 90C with -2 conductor).

 

2. Can Class C SPGFCI’s be reconditioned?

Answer: Yes

References: Article 100 definitions, 110.20, 210.2, 410.184, 680.5

110.20 Reconditioned Equipment

Reconditioned equipment shall be permitted except where prohibited elsewhere in this Code. Equipment that is restored to operating condition shall be reconditioned with identified replacement parts, verified under applicable standards, that are either provided by the original equipment manufacturer or that are designed by an engineer experienced in the design of replacement parts for the type of equipment being reconditioned.

410.184 GFCI Protection and SPGFCI Protection

Lighting equipment identified for horticultural use and employing flexible cord(s) with one or more separable connector(s) or attachment plug(s) shall be supplied by lighting outlets protected by a listed GFCI.

Exception: Circuits exceeding 150 volts to ground shall be protected by a listed SPGFCI.

680.5 GFCI and SPGFCI Protection

(A) General.

The GFCI and SPGFCI requirements in this article, unless otherwise noted, are in addition to the requirements in 210.8

(C) Above 150 Volts to Ground.

Where required in this article, ground-fault protection of receptacles and outlets on branch circuits operating at voltages above 150 volts to ground, not exceeding 480 volts phase-to-phase, single- or 3-phase, shall be provided with SPGFCI protection not to exceed 20-mA ground-fault trip current.

Informational Note: See UL 943C, Outline of Investigation for Special Purpose Ground-Fault Circuit Interrupters, for information on Classes C, D, and E ground-fault circuit interrupters.

Is SPGFCI a type of GFCI protection and 210.2 applies?

210.2 Reconditioned Equipment

The following shall not be reconditioned:

1. 1. Equipment that provides GFCI for personnel
   2. Equipment that provides AFCI protection

Not according to the definitions…

Ground-Fault Circuit Interrupter (GFCI)

A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a ground-fault current exceeds the values established for a Class A device. (CMP-2)

Informational Note: See UL 943, Standard for Ground-Fault Circuit Interrupters, for further information. Class A ground-fault circuit interrupters trip when the ground-fault current is 6 mA or higher and do not trip when the ground-fault current is less than 4 mA.

Ground-Fault Circuit Interrupter, Special Purpose (SPGFCI). (Special Purpose Ground-Fault Circuit Interrupter)

A device intended for the detection of ground-fault currents, used in circuits with voltage to ground greater than 150 volts, that functions to de-energize a circuit or portion of a circuit within an established period of time when a ground-fault current exceeds the values established for Class C, D, or E devices. (CMP-2)

Informational Note: See UL 943C, Outline of Investigation for Special Purpose Ground-Fault Circuit Interrupters, for information on Classes C, D, or E special purpose ground-fault circuit interrupters.

 

3. Would a combination type pad lock for a panelboard cabinet enclosure violate the circuit breakers being readily accessible?  The pad lock does not require a key.

Answer: No, the use of locks is commonly used practice on electrical equipment and electrical equipment rooms to keep unauthorized persons away from electrical hazards and to prevent tampering of the equipment.

The definition of readily accessible in Article 100 does not prohibit the use of locks on service equipment doors or doors of rooms containing service equipment, provided that a key or lock combination is available to those persons for whom ready access is necessary. If a tool is necessary to gain access, the equipment is not readily accessible. Please note that a key is not a tool per the definition of Accessible, readily. A padlock also will not impede access by first responders in an emergency as they have the training and tools to cut through a lock in seconds.

4. What color is required for receptacles and cover plates serving patient bed locations that are supplied by the life safety branch?

Answer: Since this is a health care question, we use NFPA 70, – 2023 the NEC article 517 and NFPA 99, Health Care Facilities may also be applicable. Since we are basing answers on the NEC, we will stick with that.

517.18 Category 2 Spaces (A) Patient Bed Location gives us the basics. In the patient bed location, we are required to have a minimum of 2 branch circuits, one from the critical branch and one from the normal branch. The receptacle AND cover plates from the critical branch are required to have what the code refers to as “a distinctive color or marking so as to be readily identifiable and shall also indicate the panelboard and branch-circuit number supplying them.”

Exception no. 3

From the commentary – Exception No. 3 allows both of the required branch circuits for a general care patient bed location to be supplied by the critical branch, provided they are supplied by two separate transfer switches. Two critical branch circuits have higher reliability than one normal and one critical branch circuit. Exception number 3 adds this by telling us “A Category 2 patient bed location served from two separate transfer switches on the critical branch shall not be required to have circuits from the normal system.”

 

5. Is it true, only three, 12-2 MC cables can be routed through a single hole in a steel stud?  My supervisors, said “that’s code, and my mom, grandpa, and great grandpa were all electricians.”

 Answer: NO. 310.15(C)(1)(d)

 Adjustment factors shall not apply to Type AC cable or to Type MC cable under the following conditions:

• • • The cables do not have an overall outer jacket.
    • Each cable has not more than three current-carrying conductors.
    • The conductors are 12 AWG copper.
    • Not more than 20 current-carrying conductors are installed without maintaining spacing, are stacked, or are supported on “bridle rings.”

Answer: No, that is false.  References, Sections 90.2(A), 310.14(A), 310.15(C)(1)

The NEC has no injunction on the number of cables that can be routed through an individual hole in a framing member, nor is the NEC a design specification.  In short, 220, 221, however many cables it takes.  Section 310.15(C)(1) specifically states “The ampacity of each conductor shall be reduced as shown in Table 310.15(C)(1) where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables not installed in raceways are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.).”  Without maintaining spacing can be subjective, however, in lengths longer than 24” is straight forward.  I personally have yet to see a framing member greater than 24” in width, as result, applying adjustment & correction factors for cables routed through a single hole in a framing member would not be required.  If the question had mentioned the cables being in contact with thermal insulation, or grouped together on a messenger, the answer would change.  See Section 330.80(B) & (C) for more.

 

6. Do shower steamers require GFCI protection?

Answer: Maybe.  References, Sections 680.1, Article 100 definition for spa or hot tub, 680.44(C).  The definition of spa or hot tub does not explicitly capture a steam shower, this is where there could be some debate.  If it were to be considered a spa, Section 680.44(C) does require the circuit supplying a fuel gas boiler/water heater to be GFCI protected, or SPGFCI protected.

 

7. Can a grounded conductor be bonded to equipment on the supply side of a service disconnecting means?  Wouldn’t this violate NEC Section 250.6(A), specifically, where there is conductivity from intervening metallic raceways.

Answer: Yes, the Grounded Conductor IS allowed to be used to bond equipment (raceways, enclosures, meter bases, and CT cans) that is installed ahead of the Service Disconnecting means. ​
References: 250.6(C), 250.24(B), 250.92(B)​
​
Per 250.6(C) Currents resulting from abnormal conditions such as Ground-Faults, & from currents resulting from the required grounding & bonding connections shall not be classified as objectionable current​
​
Per 250.24(B) Load Side connections of the grounded conductor are NOT permitted unless allowed in 250.30, 250.32, or 250.142. ​
​
Per 250.92(A) All conductive elements in and ahead of the service disconnect be bonded together. 250.92(B) tells us how, note the 1st option ​
(1) Bonding equipment to the grounded service conductor​
​
We “accept” that there are parallel connections, but they are limited to Services. We “accept” that normal neutral currents could flow on those conductive elements, but it is a tradeoff, to ensure that the “ground-fault” return path back to the utility source has a low impedance path and the BC or Feeder circuit ODPD can trip, or the conductors will “hold” until the utility stops the fault or short circuit

 

8. I have a feeder that supplies a 120-volt panel board.  Are there SPD’s that work for single phase, 2-wire, 120-volt systems?

Answer: Yes

References: 110.3(B), 242.6, 242,12, manufacturer installation instructions

242.6 Listing

An SPD shall be a listed device

110.3(B) Examination, Identification, Installation, Use, and Listing (Product Certification) of Equipment- Installation and Use

Equipment that is listed, labeled, or both, or identified for a use shall be installed and used in accordance with any instructions included in the listing, labeling, or identification.

242.12 Uses Not Permitted

An SPD device shall not be instal⁠led in the following:

(1) Circuits over 1000 volts

(2) On ungrounded systems, impedance grounded systems, or corner grounded delta systems unless listed specifically for use on these systems

(3) Where the rating of the SPD is less than the maximum continuous phase-to-ground voltage at the power frequency available at the point of application

 

9. Where a power control system is used to control and monitor a load side interconnected power production source, are the requirements found 705.12 applicable?  For example, a controlled source is connected to a bus bar via a back-fed breaker in a service panel board, where the PCS set point does not exceed that of the bus ampacity, do any of the rules in found in Section 705.12(B) still apply, such as the “120% rule”.

Answer: Interconnected power productions sources that utilize a PCS/EMS modify some of the requirements in 705.11 and 705.12 as it applies to the permitted output capacity of the source or sources. A PCS can be used to export limit a source based on the current load demands in the panelboard or other limit imposed by the utility. A 200A main breaker panelboard supplied by 4/0 AL service conductors could have up to 180A worth of PCS controlled sources connected to the panelboard non-continuously, which equals the rating of the 4/0 AL conductor, and up to 160A worth of sources continuously which equals the 80% continuous load rating of the main breaker. The PCS will monitor the current on the service conductors and will reduce the output or disconnect the source or sources if the service conductors could become overloaded.

Section 750.30(C)(2) does require the use of monitoring and controls to automatically cease current flow upon malfunction of the PCS/EMS.

 

10. Does the NEC require lay-in luminaires to be secured by ceiling wires?

Answer: The short answer is, No. The actual answer is…  It depends. The general rule in 410.36(B), summarized, states, where the ceiling framing members are supporting the fixtures, they must be securely fastened to each other and the building structure at appropriate intervals. The difference is if the ceiling is a fire resistance rated ceiling, probably under the product category Fire Resistance category code (BXUV), or if you are using a Suspended Ceiling Power Grid Systems Certified (Listed) under the category IFFA, which may require additional supports or other methods, based on the type, design, system, grid and so on.  Both the UL guide information and certifications for fire resistance rated ceilings and ceiling power grid systems can be viewed on UL Product iQ at www.ul.com/piq and enter BXUV or IFFA at the search field.

 

11. A sub-panel was added to my single-family dwelling to simply create additional space in the service panel. Some of the original branch circuits were relocated to the sub-panel from the original service panel through a 3” nipple between the two cabinets. My inspector, who is a real piece of work, failed the installation because the branch circuits are now not allowed to be routed through the service equipment panel cabinet to the sub panel cabinet.  Inspector cited NEC Section 408.3(A)(1) & (2), this must be a dream.  Is the inspector correct?

Answer: No. 408.3(A)

2) Same Vertical Section.

Other than the required interconnections and control wiring, only those conductors that are intended for termination in a vertical section of a switchboard or switchgear shall be located in that section.

Exception: Conductors shall be permitted to travel horizontally through vertical sections of switchboards and switchgear where such conductors are isolated from busbars by a barrier.

Remember, 408.3(A)(2) only applies to switchboards and switchgear, not panelboards.  The exception also only applies to switchboards and switchgear.

Answer: No, the inspector is not correct.

Section 408.3(A)(2) is specific to conductors traveling horizontally through vertical sections of switchboards & switchgear and does not include panelboards.

 

12. Is selective coordination required for essential electrical systems in health care facilities?

Answer: No, coordination required per Section 517.31(G) should not be confused with the requirements found in Section 700.32.  When reviewing the definition for selective coordination, it specifies coordination over the full range of overcurrent’s and time.  The coordination required by Section 517.31(G) does not require coordination over the full range of overcurrent’s and time.  Furthermore Item (4) of Section 517.26 exempts EES from the selective coordination requirements in Section 700.32.

 

13. Would the mounting hardware in addition to the supporting foundation for a ground mounted PV array be considered a structure, and need to comply with 2023 NEC Section 250.32?

Answer: No
It is considered as “equipment”, which CMP 1 in definitions has made clear is not a structure. 250.32 applies to buildings or structures, not to equipment.

References: Art 100 Definition of Structure and of Equipment

Structure.
That which is built or constructed, other than equipment. (CMP-1)

Equipment:
A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a part of, or in connection with, an electrical installation. (CMP-1)

 

14. Recently I was told by a plans examiner, that the size of my equipment grounding conductor needed to be sized per Section 250.122(G) in the NEC. I believe this is a bogus comment, is the plans examiner correct? Please see the snippet from the plan below, the EGC is sized based on the 90-amere fuse which the feeder’s supply.

 Answer: I don’t think this is a bogus comment based on requirements in 250.122(G)…the plans examiner is correct

References: 250.122(A) and (G)

250.122 Size of Equipment Grounding Conductors

(A) General

CU, AL, or CCA equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122. The EGC shall not be required to be larger than the circuit conductors supplying the equipment. If a cable tray, a raceway, or a cable armor or sheath is used as the EGC, as provided in 250.118 and 250.134(1), it shall comply with 250.4(A)(5) or (B)(4).

 

(G) Feeder Taps

EGCs installed with feeder taps shall not be smaller than shown in Table 250.122 based on the rating of the overcurrent device ahead of the feeder on the supply side ahead of the tap but shall not be required to be larger than the tap conductors.

The 600-amp fuse shown on the one line requires a 1AWG CU EGC, but the tap conductors are 3AWG CU.  The EGC is required to be at least a 3AWG CU, equal to the tap conductors.

250.4(A)(5) General Requirements for G&B- Effective Ground-Fault Current Path

Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.

 

15. I recently failed an inspection for having two-14-2 NM-B cables routed through a single bored hole a wooden framing member, what gives? I have read Section 334.80, has the inspector?

Answer: I have no idea what the AHJ is reading but let’s look at the requirements in 334.80 which covers ampacity of the conductors within an NM cable. Section 334.80 restricts the conductor to the 60°C ampacity column in Table 310.16 but permits the 90°C ampacity rating of the conductor insulation required in 334.112 to be used for ampacity adjustment and correction calculations as long as we don’t exceed the 60°C ampacity. Then we look at the second paragraph of this section, where more than two NM cables containing two or more current-carrying conductors are installed without maintaining spacing between the cables, through the same opening in wood framing that will be sealed with thermal insulation, caulk, or sealing foam, the ampacity of each conductor shall be adjusted in accordance with Table 310.15(C)(1) and the exception in 310.14(A)(2) doesn’t apply. But the question only had 2 14-2 NM cables, so the second paragraph doesn’t apply and there is no violation here. But for the sake of argument let’s cheat and say we have 3 14-2 NM cables and see if that changes anything.

Since we would now have 6 current carrying conductors, we adjust the ampacity by 80% using Table 310.15(C)(1). Table 310.16 shows the 90°C ampacity of a copper 14 AWG conductor as 25 Amps. 25A adjusted by 80%, equals 20A. Since 20A exceeds the 60°C ampacity of 15A in the table, the conductor is limited to 15A. If the 14 AWG conductors in the NM cables are protected by a 15A rated OCPD, the installation of 3 14-2 NM cables would still meet the requirements in 334.80.

However more information is required to verify that the installation meets the requirements of Section 300.4, maybe a nail plate is required to protect the cables from physical damage?

 

16. Is a surface mounted raceway permitted in a damp or wet location? Follow up; would the interior of an unconditioned sunroom be considered a damp location?

Answer: In response to the first question, we have to refer to Articles 386 and 388 for surface metal raceways and non-metallic surface raceways, respectively. Section 386.10(1), under uses permitted, it specifically states in dry locations. This same permission appears in 388.10(1).

Regarding the question of the sunroom, not including any local changes or requirements that may exist, the International Building Code, Building Volume, 2024 and the 2021 editions, the definition of a sunroom is a one-story structure attached to a building with a glazing area of at least 40% of the gross area of the structure’s exterior walls and roof.

This could mean the area is considered dry if the glazing protects the interior from wetness, and it is closed! This would be a site-specific decision with the answer being generally yes. It is my opinion people would not want their rugs and furniture getting wet or their drinks watered down!

 

17. I have installed temporary service equipment with a 50-ampere receptacle for construction of a new building, is the 50-ampere receptacle required to be GFCI protected? Inspector says, duh, look at Section 590.6. I have looked at the Section, and it is clear to me now, I should ask this question at the Annual Meeting, because I am lost.

Answer: No. 590.6(A)(1)

Article 590.6 only address’s 125 volt single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not a part of the permanent wiring of the building or structure and that are in use by personnel shall have ground-fault circuit-interrupter protection for personnel. There is no mention of 250v being required other than 590.6(A)(3) where it address’s the portable generators 15kw or less.

Answer: Maybe.  Where the receptacle supplies power to equipment used by personnel AND an assured equipment grounding conductor program has not been implemented, the receptacle would be required to be GFCI protected per Section 590.6(B).

 

18. Would a single SPD installed in the service equipment for an apartment complex satisfy the requirements of NEC Section 230.67, as well the requirements of 215.18, 225.42, and 760.33?

Answer: No.  As mentioned in the informational note to Section 215.18(B), SPDs are most effective when located close to the branch circuit.  There are also no exceptions to Sections 215.18, 225.42, & 760.33 where SPDs are located on the supply side of the feeders.  Maybe there should be, I’m sure CMP-3 & CMP-10 look forward to your public input.

 

19. Recently I was told by a plans examiner, that the size of my supply side bonding jumper needed to be sized per Table 250.102(C)(1) in the NEC. I’m not so sure about that, is this correct? Please see the snippet from the plan below, these are secondary conductors from the customer owned and maintained step down transformer.

Answer: Yes, the Plans Examiner is correct.
References: Art 100 Definitions, 250.30(A)(2)

Bonding Jumper, Supply-Side. (Supply-Side Bonding Jumper)
A conductor installed on the supply side of a service or within a service equipment enclosure(s), or for a separately derived system, that ensures the required electrical conductivity between metal parts required to be electrically connected. (CMP-5)

Note: The “green” wire between a transformer and the first disconnecting means with an OCPD is NOT an EGC, there is no OCPD at the source of the circuit (at the windings of the transformer), instead it is a transformer secondary (a tap per 240.21) thus, this is a supply side bonding conductor and is based on the AWG or kCM area of the secondary conductors as shown in Table 250.102(C)(1) and the notes to the Table

 

20. We are remodeling hotels and motels all over the country. When replacing receptacles in the dwelling units is it required by the NEC to provide combination AFCI protection for the replacement receptacles?

Answer: Maybe.  It depends on if we’re talking hotels and motels OR dwelling units.

Hotels and motels- no

Dwelling units- yes

References: 210.12, 406.4

406.4 General Installation Requirements

Receptacle outlets shall be located in branch circuits in accordance with Part III of Article 210. General installation requirements shall be in accordance with 406.4(A) through (G).

(D) Replacements

Replacement of receptacles shall comply with 406.4(D)(1) through (D)(8), as applicable. AFCI type and GFCI type receptacles shall be installed in a readily accessible location.

(D)(4) AFCI Protection

If a receptacle located in any areas specified in 210.12(A), (B), or (C) is replaced, a replacement receptacle at this outlet shall be one of the following:

(1) A listed outlet branch-circuit type AFCI receptacle

(2) A receptacle protected by a listed outlet branch-circuit type AFCI type receptacle

(3) A receptacle protected by a listed combination type AFCI circuit breaker

Exception: Section 210.12(E), Exception, shall not apply to replacement of receptacles.

210.12(A) AFCI Means of Protection

210.12(B) Dwelling Units

210.12(C) Dormitory Units

210.12(D) Other Occupancies [not referenced in 406.4(D)(4)]

All 120-volt, single-phase, 10-, 15-, and 20-ampere branch circuits supplying outlets or devices installed in the following locations shall be protected by any of the means described in 210.12(A)(1) through (A)(6):

(1) Guest rooms and guest suites of hotels and motels

(2) Areas used exclusively as patient sleeping rooms in nursing homes and limited-care facilities

(3) Areas designed for use exclusively as sleeping quarters in fire stations, police stations, ambulance stations, rescue stations, ranger stations, and similar locations

Note- if the scope of work increases past just replacing receptacles and moves to branch circuit extension, modification, or replacement, 210.12(E) applies:

(E) Branch Circuit Wiring Extensions, Modifications, or Replacements

If branch-circuit wiring for any of the areas specified in 210.12(B), (C), or (D) is modified, replaced, or extended, the branch circuit shall be protected by one of the following:

(1) By any of the means described in 210.12(A)(1) through (A)(6)

(2) A listed outlet branch-circuit-type AFCI located at the first receptacle outlet of the existing branch circuit

Exception: AFCI protection shall not be required where the extension of the existing branch-circuit conductors is not more than 6 ft and does not include any additional outlets or devices, other than splicing devices. This measurement shall not include the conductors inside an enclosure, cabinet, or junction box.

 

21. Are energy storage systems exempt from the requirements found in the 2024 IRC Section R330, where they have a passing UL 9540A test report, but are not marked “for use in habitable spaces”?

Answer: Absolutely NOT! For a residential ESS to be exempt, Exception 1 to Section 330.1 states that the ESS must be listed and labeled for use in habitable spaces. That listing and labeling is reserved for residential ESS that pass the UL 9540A Thermal Runaway Testing at the cell level. To pass at the cell level, the Li-ion cell cannot be forced into thermal runaway through any of the permitted propagation methods and any ventilated off-gassing from the cell must be non-flammable. It is impossible for any Li-ion NMC or LFP chemistry to pass at the UL 9540A cell or module level testing. Those cell  chemistries can only pass at UL 9540A unit level test and must be installed in accordance with all of the applicable requirements in Section 330 of the 2024 IRC, which also mirrors the requirements of Chapter 15 of NFPA 855. The complete UL 9540A test report should be reviewed by the AHJ for installation compliance, as the report will indicate the minimum required separations and will contain the minimum required room size for the ESS installation, if indoors. A complete UL 9540A test report will contain the entire, cell level, module level, and unit level test data.

 

22. Can MC cables used for fixture whips lay on the ceiling grid and tiles between the required supports? My inspector failed me and said they cannot be in contact with the suspended ceiling system because the whip is then exposed to physical damage, what do you think? Is the inspector, right?  I think this inspector has been sniffing glue personally.

Answer: First of all, the inspector is always right!

Article 330 is for Metal Clad (MC) cable. 330.10 provides the uses permitted and (A)(2) provides the uses for power and lighting. This is further reinforced in 330.30 for supporting of the MC where item (D)(2) allows for up to 6 feet of unsupported MC to a luminaire in an accessible ceiling.

 

23. What is the minimum wire bending space required for 400 kcmil conductors with a single termination and the conductors are not entering or leaving the opposite wall?

Answer: 6”. 312.6(A) Table. Verify what are the different columns mean (1, 2, 3, 4)

B) Wire-Bending Space at Terminals.

Wire-bending space at each terminal shall be provided in accordance with 312.6(B)(1) or (B)(2).

(1) Conductors Not Entering or Leaving Opposite Wall.

Table 312.6(A) shall apply where the conductor does not enter or leave the enclosure through the wall opposite its terminal.

Answer: Depends.  References, 312.6, 305.5, 314.28(E)(3), 404.28, 409.104(B), 430.204, 408.3(G), 376.55(B)(3), 430.97(C), too many others to list.

In general, specific equipment wire bending space for systems 1000-volts AC and less reference Section 312.6(B).  Table 312.6(A) would require a space of six inches for this question.

 

24. Is there a minimum disconnect rating for a two-family dwelling feeder? The calculated load is 89.7-amperes?

Answer: 100-amperes.  References, Article 100 definitions & 225.39.

Interesting question, both one and two-family dwellings are defined within Article 100.  However, Section 225.39 includes a minimum rating for one-family dwellings, and not a two-family dwelling.  How about that, CMP-10 looks forward to the PI.  The answer is then obvious, there is no minimum for a two-family dwelling, so…  The rating would need to simply be the larger of the calculated loads to be supplied, as per the parent text, or, sub-division (B), for a two-wire circuit.

 

25. Can building steel be used as an effective ground fault current path?

Answer: NO.
References: 250.4(A)(4) and (5), 250.68(C)(2), 250.118(B), 250.134.

The metal frame of a building is permitted to be used as a conductor to interconnect Grounding Electrodes.

That interconnection is part of the “effective grounding” path, but this is NOT the “effective ground-fault” path referenced in 250.4(A)(4) and (5).

It is specifically prohibited from being used as an EGC by 250.118(B).

250.134 requires equipment to be connected through the EGC types listed in 250.118(A)

250.136 allows metal racks to bond equipment mounted on the racks if the rack is connected to the EGC

 

26. Is there a way to perform a cubic inch calculation for the cabinet of a dwelling service panel board? What is the code reference? More and more cabinets are being crammed with CT’s & associated monitoring equipment/components for energy management systems.

Answer: Yes

References: 312.7, 312.8, Chapter 9- Table 5, Google AI

312.8 Switch and OC Device Enclosures

The wiring space within enclosures for switches and OC devices shall be permitted for other wiring and equipment subject to limitations for specific equipment as provided in 312.8(A) and (B).

(B) Power Monitoring or Energy Management Equipment

The wiring space of enclosures for switches or OC devices shall be permitted to contain power monitoring or energy management equipment in accordance with 312.8(B)(1) through (B)(3).

(1) Identification: Power monitoring or energy management equipment shall either be identified as a field installable accessory as part of the listed equipment or be a listed kit evaluated for field installation in switch or OC device enclosures.

(2) Area: The total area of all conductors, splices, taps, and equipment at any cross section of the wiring space shall not exceed 75% of the cross-sectional area of that space.

312.7 Space in Enclosures

Cabinets and cutout boxes shall have approved space to accommodate all conductors installed in them without crowding.

 

27. If a solar array is located on a detached garage with a different solar array located on the dwelling (same property and system). Is the solar array on the detached garage required to have a separate disconnect located on the garage?

Answer: I view this installation as having to separate PV systems with 1 system on the dwelling unit, and a second PV system on the garage. Section 690.4(D) permits multiple systems and since the PV systems are remotely located from each other, a directory providing the location of each power source disconnecting means in accordance with 705.10 is required to be provided at each PV system disconnecting means. Each PV system will require its own PV system disconnecting means in accordance with Section 690.13 and the PV Rapid Shutdown Initiation Device or Devices must initiate the rapid shutdown of both PV systems with rapid shutdown functions connected to the service in accordance with 690.13(C).

 

28. Does the NEC require switched receptacles, or “half hot’s”, as permitted by exception 1, to Section 210.70(A)(1), to be permanently marked “controlled”?

Answer: No. This is covered by 210.70 (A)(1) Exception No. 1. within a commercial building, the controlled receptacles are required by 405.11.1, #3 to be identified in accordance with NEC section 406.3(F).  However, if the controlled part of the receptacle is a 125-volt, 15- and 20-ampere receptacles that are controlled by an automatic control device, or that incorporate control features that remove power from the receptacle for the purpose of energy management or building automation, shall be permanently marked with the symbol shown in Figure 406.3(F) and the word “controlled.”

For receptacles controlled by an automatic control device, the marking shall be located on the receptacle face and visible after installation.

In both cases where a multiple receptacle device is used, the required marking of the word “controlled”, and symbol shall denote which contact device(s) are controlled.

Before you get all excited, there is also an Exception which says The marking shall not be required for receptacles controlled by a wall switch that provide the required room lighting outlets as permitted by 210.70.

 

29. The newly rewritten Section, 110.26(A)(6), states the required working space be kept free and clear and the floor, grade or platform be as level as practical. Would a window well cover, rated for human load be compliant where located partially below a panel board?

Answer: Maybe. 110.26(A)(6).

This is an example of a (gray area) of the code. This is a judgment call for the AHJ. There should be several points to consider, such as, support of the cover, stumbling hazard and “level as practical” when determining that it’s a safe installation and meets 110.26 requirements.

Answer: Sure, why not?  Reference Section 110.26 & Merrian-Webster definition for practical.

A yes or no will depend on rather the window well cover is as level as practical.    Merrian-Webster defines practical as “of, relating to, or manifested in practice or action : not theoretical or ideal.”  With that, most solid window well covers, with exception to the “bubble type” would in my opinion satisfy the requirements found in Section 110.26(A)(6).

 

30. Can busways be used as service equipment?  Do they need to comply with Section 230.62(C)?

Answer: Yes, and Yes.  Reference, Section 230.43(9), 230.62(C), 368.1, 368.10 & 368.12.

Section 230.43, item (9) permits busways as the service entrance conductors.  I am not sure if there are busways manufactured that comply with Section 230.62(C), however, I can safely say they would need to comply with the barrier requirements.

 

31. In Article 220, why are there two methods of calculating dwelling unit services? The standard and optional method, the final calculations can be very different.

Answer: Because

References – old editions of the ROP and ROC, local utilities, and history with local jurisdictions that allowed simpler methods of calculating loads.

To provide a simpler, more streamlined method of calculations for dwelling units and to recognize the greater diversity of loads in dwellings than in commercial or industrial facilities.

I have found a form of optional calculations for dwelling units going as far back as the 1965 edition. (Back this far, you need to have an actual ROC and ROC to see WHY revisions were made.

The online records for 1965 and earlier editions archived only show the result, not what or why changes were made)

Keep in mind, even with the optional method the actual load is rarely if ever as much as the rating of the service.

Utilities records have proven the viability of the diversities used

 

32. Can 10/3 UF cable be secured directly to the underside of floor joists in a crawl space without protection? How about to the exterior of a dwelling, where the cable is certified for use in direct sunlight?

Answer: Maybe and maybe

References: 340.10, 340.12, 334.15

340.10 Uses Permitted

Type UF cable shall be permitted as follows:

(4) Installed as nonmetallic-sheathed cable. Where so installed, the installation and conductor requirements shall comply with Parts II and III of Article 334, except for 334.12(B), and shall be of the multiconductor type.

340.12 Uses Not Permitted

Type UF cable shall not be used as follows:

(9) Where exposed to direct rays of the sun, unless identified as sunlight resistant

Informational Note: The sunlight-resistant marking on the jacket does not apply to the individual conductors.

(10) Where subject to physical damage

334.15 Exposed Work

In exposed work, except as provided in 300.11(B), cable shall be installed as specified in 334.15(A) through (C).

(B) Protection from Physical Damage

Cables shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, RTRC marked with the suffix -XW, or other approved means.

334.15 Exposed Work

In exposed work, except as provided in 300.11(B), cable shall be installed as specified in 334.15(A) through (C).

(B) Protection from Physical Damage

Cables shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, RTRC marked with the suffix -XW, or other approved means.

 

33. A residence built in the 1930’s was undergoing minor water damage repairs, and the extension of a concealed knob and tube branch circuit was needed, does the NEC allow this installation by “special permission”, and is it required to be in writing from the AHJ?

Answer: Section 394.10 Uses Permitted for Concealed Knob-and-Tube Wiring permits this type of wiring method to be installed within the hollow spaces of walls and ceilings, or in unfinished attics and roof spaces under 2 list items. List item 1 is for an extension of an existing installation. List item 2 is anywhere else under special permission. So, for an extension of an existing circuit, special permission is NOT required by the electrical inspector. But if for some crazy reason someone wanted to install a new Concealed Knob-and-Tube branch circuit, they could ask for and then the electrical inspector could grant special permission which is written consent to install it. However, the insurance company covering the repair could also be an AHJ, and they may have policies prohibiting the extension of any Concealed Knob-and-Tube branch circuit due to the strict limitations in the NEC with these circuits and the related safety issues the insurance industry has had with them. Replacement with another Chapter 3 wiring method may be the best solution.

 

34. Does the NEC require wire connectors for grounding & bonding, such as, cold water clamps, acorns, bond bushings, etc., to be torqued? Are these products furnished with installation instructions? My supply house is giving me some very strange looks, but the inspector insisted they be torqued per the instructions, at this point I believe it may be easier to find a unicorn than the instructions.  Please help.

Answer: UL Certifies (Lists) these clamps under the product category Grounding and Bonding Equipment (KDER), Grounding and Bonding Equipment for Communications, and in UL Product iQ under KDER, KDSH for communication. The devices are listed for compliance with UL 467, the Standard for Grounding and Bonding Equipment. The standard does require a Tightening Force for Ground Clamp Test in clause 9.2, though the standard does not require a torque marking.  The UL principal engineer is looking into this and will try to address the issue in the standard.

9.2 Tightening force for ground clamps

A tightening torque of 16.9 N·m (150 lbf-in) shall be applied to each clamping bolt or screw. For a clamping screw intended to be tightened only by a screwdriver, a torque of 5.6 N·m (50 lbf-in) shall be applied.

 

35. My inspector cited me for not marking my service equipment with the available fault current, and date it was calculated, would the NEC prohibit me, a licensed electrician, from providing the calculation? You know there is an app for that, also the service is for a one family dwelling, is this really required?

Answer: 110.24(A) & (B) Link: to SE Fault Current App. https://tools.se.app/faultcalc/FaultCalc.html

It appears the question possibly has a typo with regards to the inspector red tagging the contractor for not marking the equipment. However, as I read through the question it sounds like the contractor applied the available fault current information on a residential installation when the code does state for “other than dwelling units”. There is nothing wrong with going above code when a contractor performing an electrical installation.

110.24 Available Fault Current.

(A) Field Marking.

Service equipment at other than dwelling units shall be legibly marked in the field with the available fault current. The field marking(s) shall include the date the fault-current calculation was performed and be of sufficient durability to withstand the environment involved. The calculation shall be documented and made available to those authorized to design, install, inspect, maintain, or operate the system.

 

36. Are barriers required for energized parts, that are exposed and part of a main lug only sub panel in a basement of a dwelling? The feeders are not feeder taps or secondary conductors, just plain old boring feeders.

Answer: No.  Reference Section 215.15

Plain old boring feeders are not covered by Section 215.15, it is specific to feeder taps, and transformer secondary conductors.

 

37. What NEC Article, or specific Section applies to new cold therapy tubs? What if the unit requires an accessible receptacle within six feet, does GFCI protection cure everything?

Answer: See below

The receptacle supplying the equipment must have either GFIC or SPGFCI  per 680.5(B) or (C) as applicable.

It also must be located per the distances specified. If the unit instructions call for a connection within that 6’ distance contact the NRTL that listed the item!

References: 680.45 Permanently Installed Immersion Pools
(electrical installations at) require compliance with Parts I, II, and IV of 680.

Part VI of 680 for Therapeutic use (680.60 – 680.62)

680.45 requires the installation of an immersion pool to comply with the following:
Part I – General  (680.5 GFCI or SPGFCI required only where required by article)
Part II – Permanently Installed Pools (680.22 GFCI/SPGFCI for other general-purpose receptacles which must be at least 6’ away and if <20’ the receptacles must also have the GFCI/SPGFCI protection).
Part IV. Spas, Hot Tubs, Permanently Installed and Self-Contained Spas and Hot Tubs

680.43 requires receptacles to be further than 6’ and less than 20’ and be GFCI or SPGFCI

 

38. During a courtesy rough inspection of a multifamily unit, the inspector stated that the panel board located behind the bedroom entry door impeded access to and egress from the working space and would approve the install if I adjusted it out from behind the door, where does the code mention this?

References: 110.26

110.26 Spaces About Electrical Equipment

Working space, and access to and egress from working space, shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of such equipment. Open equipment doors shall not impede access to and egress from the working space. Access or egress is impeded if one or more simultaneously opened equipment doors restrict working space access to be less than 24 in. wide and 6 1⁄2 ft high.

 

39. I am new to the industry and have recently been turned down for final inspection on a rooftop unit for not installing a readily accessible disconnect within sight from the unit. The inspector cited NEC Section 440.14; however, I explained that per NEC Section 422.31 & and the Article 100 definition for an appliance, I would be allowed to follow the provisions of Section 110.25 and install a listed type locking means that remains in place on the circuit breaker, what’s the difference?

Answer:

The difference is that Article 440 has purview over the installation of Air-Conditioning and Refrigerating Equipment, not Article 422 for Appliances, and quoting the wrong code sections to the inspector isn’t going to help even if the equipment falls under the broad definition of appliance in Article 100. For someone who is new to the industry, I view this as a valuable learning opportunity!

Section 440.14 clearly states that the disconnecting means for air- conditioning or refrigerating equipment must be readily accessible and within sight of the equipment. The installation in question does not appear to meet either of the required conditions of use in either exception to this Section.

The 2023 NEC added a redundant sentence to the end of this section stating that the disconnecting means also meet the working space requirements in Section 110.26. However, that Section has always applied as performing an absence of voltage check on the load side terminals of a disconnecting means to create an electrically safe working condition in accordance with NFPA 70E falls under “examination” in Section 110.26(A).

 

40. Does the NEC require metallic wireways, or gutters to be listed/certified? How about steel four square boxes?

Answer: Metal wireways are covered by Article 376, and Section 376.60 requires a metallic wireway to be listed when used as an equipment grounding conductor.  The construction requirements are found in 376.100, however, the only requirement for listing is as previously mentioned even though they are required to have the manufacturer’s name or trademark visible after installation.

Wireways are Listed (certified) under the UL product category Wireway, Auxiliary Gutters and Associated Fittings category code, ZOYX on Product iQ at www.ul.com/piq and enter ZOYX at the search field.

Regarding the question for steel 4 square boxes, the general rule is they are not required to be listed by Article 314.  There are requirements for having a listed box, such as if it is nonmetallic and provides grounding means for connection to metallic wiring methods, use in damp or wet locations, and when supporting luminaires more than 50lb’s.  UL Lists (Certifies) these under the product category Metallic Outlet Boxes category code QCIT.  Nonmetallic Outlet Boxes are covered under category code QCMZ.  You can find the UL guide information and listings (Certifications) on UL Product iQ at www.ul.com/piq and enter QCIT or QCMZ at the search field.

 

41. For certain installations does the NEC require the calculated available fault current be known and a copy provided to complete an arc flash study? If this is not a NEC compliance requirement, is it required elsewhere, such as NFPA 70E?

Answer: 110.16, 110.24, 240.67, 240.87, 480.7, and 706.15 apply.

42. Does the NEC have a definition for a sunroom? I’m asking because I have enclosed the back patio of my dwelling with glass windows and glass doors, with no heating or cooling for the newly enclosed space, should I be installing receptacles in the sunroom per NEC Section 210.52(A)?

Answer: No, and most likely.  Reference, 2024 IRC definition for a sunroom

Section N1101.6 defines a sunroom as, “a one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of the structures exterior walls and roof.”  In short, yes, sunrooms shall meet the requirements of Section 210.52(A).  If the space described does not meet the definition, it may not require receptacle outlets as per Section 210.52(A).

 

43. Where is the grounding electrode termination required for a residential service, I was recently informed that the meter enclosure was not accessible, and it would have to be terminated within the service disconnect on the grounded conductor terminal. Is this always the case?

Answer: – You are permitted to make a connection of the Grounded Service Conductor to the GEC at ANY accessible point from the load end of the overhead service conductors, service drop, underground service conductors, or service lateral to the terminal or bus to which the grounded service conductor is connected at the service disconnecting means

References: 250.24(A)(1)

You can make the connection at locations such as
the Weatherhead of a mast strike, or
in the Service Disconnecting means or
On a common Ground Bar outside of the Service Disconnecting means.

Metering equipment including CTs are often locked by the utility and most AHJs would consider that to be NOT accessible and thus prohibit a connection in a locked enclosure.

That is not to say a utility cannot require a ground rod and GEC connected to the neutral (grounded conductor) lug in a meter enclosure, that ground rod and GEC are not considered as the required grounding electrode for the electrical service. If installed, it must be bonded to the Grounded Conductor.

There are rules for how to size it (250.66) and what connectors to use (250.8) and to use Interior water piping or metal frame as a connector (250.68(C)) that must be followed as well

 

44. I was recently informed that I could not install SER cable underground in PVC, the cable contains XHHW type conductors, why not?

Answer: Because the Code states you can’t

References: 338.12, phone a friend

338.12 Uses Not Permitted

(A) Service-Entrance Cable

Type SE cable shall not be used under the following conditions or in the following locations:

(2) Underground with or without a raceway

Phone A Friend Reply:

The scope of UL 854 Service-Entrance Cables states: “Type SE (above-ground) power cables for installation in accordance with Article 338”. So, even the UL standards stipulate long-term above ground use.

As a manufacturer, the outer sheathing was not evaluated for the prolonged exposure to moisture in a direct burial, saturated environment. We test for water exposure, UV and so on, but not for prolonged direct burial or potential submersion as we know will happen in any buried raceway.

The sheathing on SE Cable was never evaluated to withstand the physical stresses from soil pressure, potential movement. Now, to that they say but it’s in a raceway….sure but those raceways again get filled with water.  While the inner conductors are “wet” rated, the assembly is created in accordance with UL 854 and that prohibits the installation underground period because we do not TEST for the long-term exposure.

 

45. Does NEC Section 430.2 require a NRTL to apply a label on my rebuilt 20 horsepower, 480-volt, 3-phase motor? How would an AHJ verify credentials of a local motor shop, and should it be done prior to performing the repairs?

Answer:

Maybe! Motors have been reconditioned since the beginning of the electrical industry and is a very common practice. Section 430.2 requires any reconditioned motors identified for use in hazardous or classified locations to be listed as reconditioned if installed in those locations. In those instances, yes, the motor will be required to be listed by an OSHA NRTL that is approved by OSHA to provide that type of certification and will bear their associated listing mark.

For other types of motors, we need to look at the requirements in Section 110.20 which allows reconditioned equipment where permitted in the NEC. 110.20(A) covers the reconditioning requirements for equipment required by the NEC to be listed, 110.20(B) covers the reconditioning requirements for equipment that’s not required to be listed by the NEC, and 110.20(C) allows the AHJ to make the determination if the requirements (A) or (B) cannot be met.

The only motors that the NEC requires to be listed in Article 430 are reconditioned motors for hazardous locations, so all other types of reconditioned motors will probably meet one of the 2 requirements in Section 110.20(B). The motor could be listed, or field labeled as reconditioned, or just have the reconditioning performed in accordance with the original equipment manufacturer instructions by a local motor re-wind shop.

Reconditioned equipment also must be marked in accordance with Section 110.21(A)(2). So, if Brian’s motor shop re-wound this 20 horsepower, 480-volt, 3-phase motor, I would be required to mark the motor as reconditioned, apply my company’s name with the date I reconditioned the motor. If the motor was originally listed, I would be required to remove listing mark or make the original listing mark permanently illegible. But there is no requirement to have this reconditioned motor to be listed as reconditioned or field evaluated as reconditioned under the requirements of 110.20(B)(2) unless it is being installed in a hazardous location.

 

46. Would Section 406.3(F) apply to office furniture, or furnishings, such as free-standing cubicles?

Answer: It depends.  I would say no if they were Listed (Certified) office furnishings and are Listed (Certified) for compliance with UL 1286, the Standard for Office Furnishings for installation in accordance with NEC Article 605 Office Furnishings.  UL Solutions Lists (Certifies) office furnishings under the product category Office Furnishings, category code QAWZ on UL Product iQ at www.ul.com/piq enter QAWZ at the search field.  The NEC doesn’t apply to the inside of a Listed (Certified) product, the standard applies.  If these office furnishings were not Listed (Certified), then yes the NEC would apply to them.

 

47. Can a generator disconnect be permitted to be the overcurrent protective device located within the generator behind a locked hinged cover, door, or enclosure panel without additional locking means or direction labels?

Answer:

Look at 445.18 which is the requirement for the generator disconnecting means. The disconnecting means shall be permitted to be located within the generator behind a hinged cover, door, or enclosure panel. Where the generator disconnecting means is located within the generator, a field applied label meeting the requirements of 110.21(B) shall be provided indicating the location of the generator disconnecting means.

However, the question also included the overcurrent device which for the generator is in 445.12 and it does include additional requirements on location or access.  The question is vague but if the installer wants the generator disconnect to also serve as the building disconnect then 700.12(D)(4), 701.12(D)(3), 702.12 require the disconnecting means to be readily accessible and located within sight of the building or structure supplied.

445.18 Disconnecting Means.

(A) Disconnecting Means.

Generators other than cord-and-plug-connected portable generators shall have one or more disconnecting means. Each disconnecting means shall simultaneously open all associated ungrounded conductors. Each disconnecting means shall be lockable open in accordance with 110.25.

48. I recently completed a single fix & flip residential remodel, where I replaced the existing range & dryer receptacles with new receptacles of like voltage and ampere ratings. The branch circuit wiring remained as is, does the NEC require the branch circuit wiring to be replaced? How about GFCI protection, should the receptacles be GFCI protected?

Answer: No, that would be crazy & yes. References, common sense and Sections 210.8(A)(11) & 406.4(D)(3).

My thought, wiring that was compliant when installed cannot magically become non-compliant.  Where receptacles are replaced within a residential laundry area, 406.4(D)(3) would require the receptacles to be GFCI protected, as Section 210.8(A)(11) requires GFCI protection.

 

49. When installing parking lot lighting, I was instructed to bond the rebar cage to the ground rod as detailed on the plan and then extend up to the equipment grounding conductor lug on the light pole, does the code require this or can I just leave them separated?

Answer: NO, you must bond any auxiliary electrodes installed to the grounding electrode system or the EGC of the circuit.

You cannot use the GEC as an equipment grounding conductor for the light.

The earth cannot be used as an EGC!

You MUST install an EGC to the light and bond the EGC to the light.

Reference 250.4(A)(5), 250.54 Auxiliary Grounding Electrodes, 250.58 Common Grounding Electrodes

250.4(A)(5) The earth is not an effective ground-fault current path.

250.54 requires the GEC from the ground rod must be bonded to the EGC wire or to the conductive surface of the pole that is bonded to the EGC

250.58 requires that if multiple grounding electrodes are used, all grounding electrodes must be tied together to become the “same” grounding electrode

 

50. Are standard type light switches allowed inside a shower enclosure? The contractor claims the enclosures were manufactured that way and it should pass inspection.

Answer: Possibly

References: 404.4

404.4 Damp or Wet Locations

(C) Switches in Tub or Shower Spaces

Switches shall not be installed within tub or shower spaces unless installed as part of a listed tub or shower assembly.

 

51. What NFPA Standard covers flywheel type ESS, or other stationary energy storage systems and what NEC Articles would apply for commercial applications?

Answer:

That would be NFPA 855 Standard for the Installation of Stationary Energy Storage Systems, which covers all types of Energy Storage Systems. In addition to the requirements of Chapters 4 through 8, Chapter 13 covers the specific requirements for Flywheel Energy Storage Systems. As for the NEC, Chapter 1-4 always apply, and the installation must also meet the applicable requirement in Article 706 for Energy Storage Systems. Part VI of Article 706 covers other energy storage technologies, and Section 706.51 covers Flywheel ESS.

 

52. Will the NEC allow the use of listed standard PVC terminal adapters with HDPE conduit? Does the answer change if the HDPE conduit is installed above ground and on the exterior of a building?

Answer: I would say no, Listed PVC terminal adapters are Listed for use on PVC conduit only.  See NEC 110.3(B).  UL Solutions Lists (Certifies) terminal adapters under the product category Conduit Fittings category code DWTT.  You can find the UL guide information and Listings (Certifications) on UL Product iQ at www.ul.com/piq, enter DWTT at the search field.

The DWTT guide information states:

“PVC Conduit Fittings — All PVC conduit fittings are designed for connection to both Schedule 40 and 80 PVC conduit by the use of suitable solvent-type cement. Instructions supplied by the solvent-type-cement manufacturer describe the method of assembly and precautions to be followed.”

Under the heading Nonmetallic Fittings- it states that Nonmetallic fittings suitable for use with rigid polyvinyl chloride conduit, high-density polyethylene conduit or reinforced thermosetting resin conduit are identified by the appropriate marking on the carton.

So, check the carton to see what it has been Listed for use with.

 

53. Does Section 110.3(B) permit installation instructions to be obtained with a QR code on the equipment, product, component, etc.?

Answer: 110.3(B) Installation and Use.

Equipment that is listed, labeled, or both, or identified for a use shall be installed and used in accordance with any instructions included in the listing, labeling, or identification.

Informational Note: 

The installation and use instructions may be provided in the form of printed material, quick response (QR) code, or the address on the internet where users can download the required instructions.

 

54. Why did NFPA 70B become a standard, and not just a recommended practice? Should jurisdictions require permits and the associated inspections for maintenance, how about reconditioning of equipment?

Answer: Why not, no, and the NEC does cover reconditioning.  Reference, NFPA 70B Section 1.1, NEC Section 90.2(A), and the “dot two placeholder”.

Question one, NFPA 70B, the “Standard for Electrical Equipment Maintenance,” transitioned from a recommended practice to a standard to establish a consistent, enforceable framework for electrical equipment maintenance, enhancing safety and reliability across various facilities.

Question two, Section 1.1 provides the scope NFPA 70B, which covers the preventative maintenance of electrical, electronic, and communications systems and equipment.  In my humble opinion this is beyond the application of the NEC, and rather, within a facility maintenance team’s purview after occupying a building or structure with a Certificate of Occupancy.

Question three, the .2 placeholder within a specific article will provide guidance on reconditioning.

 

55. Does the code allow office furnishings of the freestanding, wired partition type to extend up to the ceiling, and possibly penetrate the ceiling slightly to secure the partition in some but not all areas of an office tenant finish remodel?

Answer: Maybe, but in general no
References: 605.3 and 410.62(C)(1)(c)

605.3 General.

Wiring systems shall be identified as suitable for providing power for lighting accessories and utilization equipment used within office furnishings. A wired partition shall not extend from floor to ceiling.
Exception: Where permitted by the authority having jurisdiction, these relocatable wired partitions shall be permitted to extend to, but shall not penetrate, the ceiling.

However, if permitted by the local AHJ, 410.62 must also be complied with. The answer has changed slightly with the 2020 Edition of the NEC. Previous editions specially allowed for a 6-inch extension above the suspended ceiling as follows:​
​
410.62(C)(1)(c): Is terminated in a grounding-type attachment plug cap or busway plug or is a part of a listed assembly incorporating a manufactured wiring system connector in accordance with 604.6(C) or has a luminaire assembly with a strain relief and canopy having a maximum 152mm (6in.) long section of raceway for attachment to an outlet box above a suspended ceiling​
​
This was changed in the 2020 edition to read simply:​
Listed luminaires connected using listed assemblies that incorporate manufactured wiring system connectors in accordance with 604.6(C) shall be permitted to be cord connected.​

From the enhanced content in LINK: the supply cord is not permitted to penetrate a suspended ceiling, because the cord is required to be visible along its entire length.​

Section 410.62(C)(1)(c) permits a listed manufactured wiring system connector that is part of a fabricated assembly to supply the luminaires in place of a grounding-type attachment plug. Certain listed assemblies with a 6-inch maximum section of raceway are permitted to be installed above a suspended ceiling.​

Supply cords cannot be used as a supporting means, and the luminaires must be suspended directly below the outlet boxes supplying each luminaire. If the luminaire is suspended below the lift-out-type ceiling, the cord is not permitted to penetrate the ceiling, unless it is part of a listed luminaire assembly as described in 410.62(C)(1)(c).

 

56. Would the masonry/paver wall adjacent to the self-contained hot tub, be considered part of a perimeter surface, and require equipotential bonding?

Answer: Definitely maybe and probably yes

References: 680.40, 680.42

Part IV. Permanently Installed and Self-Contained Spas and Hot Tubs and Permanently Installed Immersion Pools

680.40 General

Electrical installations at spas and hot tubs shall comply with the provisions of Part I and Part IV of this article

680.42 Outdoor Installations

A spa or hot tub installed outdoors shall comply with the provisions of Parts I and II of this article, except as permitted in 680.42(A) and (B), that would otherwise apply to pools installed outdoors.

Flexible Connections

(B) Bonding

Bonding by metal-to-metal mounting on a common frame or base shall be permitted. The metal bands or hoops used to secure wooden staves shall not be required to be bonded as required in 680.26. (cont)

Equipotential bonding of perimeter surfaces in accordance with 680.26(B)(2) shall not be required to be provided for spas and hot tubs where all of the following conditions apply:

(1) The spa or hot tub shall be listed, labeled, and identified as a self-contained spa for aboveground use

(2) The spa or hot tub shall not be identified as suitable only for indoor use

(3) The installation shall be in accordance with the manufacturer’s instructions and shall be located on or above grade

(4) The top rim of the spa or hot tub shall be at least 28 in. above all perimeter surfaces that are within 30 in., measured horizontally from the spa or hot tub. The height of nonconductive external steps for entry to or exit from the self-contained spa shall not be used to reduce or increase this rim height measurement.

 

57. Does NEC Section 750.30(C)(1) prohibit the current setpoint from being set to the bus ampacity, rather than the breaker size protecting the bus?

Answer:

Section750.30(C) covers the use of an EMS to limit the amount of current on a branch circuit, feeder, or service conductor. A busbar, by definition in Article 100 is a conductor. But if we have feeder or service conductors supplying power to the busbar, then the ampacity of those conductors also needs to be taken into consideration so they do not become overloaded. A circuit breaker is not a conductor, but depending on the installation the continuous load rating of the device needs to be taken into consideration. The current setpoint of an EMS used for a 705.13 interconnection to a backfed circuit breaker may need to be set to 80% of the breaker rating which would be less than the rating of the conductor. Stay tuned to the 2026 NEC which provides clarity that the EMS is to prevent conductors, sources, and/or equipment from being overloaded and that the current setpoint be considered as a continuous load.

 

58. I recently discovered that ENT is made from polyvinyl chloride, does the NEC allow the use of standard PVC terminal adapter type fittings with ENT type flexible raceways or must the fittings be listed for ENT only?

Answer: If the ENT is made of PVC, then the answer is yes if you follow the instructions provided with the ENT.  ENT is Listed (Certified) under the UL Solutions product category Electrical Nonmetallic Tubing category code FKHU.  The FKHU guide information states- Fittings — The outside diameters of ENT are such that standard connectors, couplings and outlet boxes for rigid PVC conduit can be employed for ENT that is also constructed of PVC. Installation instructions are provided with each bundle or coil of ENT outlining the procedure to be used when employing cemented-on PVC conduit fittings and outlet boxes. These techniques include the specific cement to be used as well as its application method. Other fittings are covered under Electrical-nonmetallic-tubing Fittings (FKKY).

The guide information and Listings (Certifications) can be found on UL Product iQ at www.ul.com/piq enter FHKU or FKKY at the search field.

 

59. Are there minimum and maximum size drain holes for outline lighting and sign systems when they are installed in wet locations?

Answers: Yes. 600.9 (D) Wet Location.

Signs and outline lighting system equipment for wet location use, other than listed watertight type, shall be weatherproof and have drain holes, as necessary, in accordance with the following:

Drain holes shall not be larger than 13 mm (1⁄2 in.) or smaller than 6 mm (1⁄4 in.).

Every low point or isolated section of the equipment shall have at least one drain hole.

Drain holes shall be positioned such that there will be no external obstructions.

 

60. I will be installing a portable mobile sign in a damp location outside, should I install additional Class A GFCI protection? These were not manufactured with integral GFCI protection.

 

61. Is there a difference for Type 1, and Type 2 SPDs, and can I install either on the supply side of the service disconnect, or under the bus bar bolts?

Answer: Yes, there is a difference and, you may only install Type 1 SPDs ahead of the Service.​
Type 2 devices must be installed on the load side of an OCPD​

Reference ​
242.13 and 242.14​

For further information about SPDs see:​
​
EATON https://www.eaton.com/us/en-us/products/backup-power-ups-surge-it-power-distribution/surge-protection.html ​

NEMA https://www.nemasurge.org/what-is-spd/​

SCHNEIDER https://www.se.com/au/en/product-subcategory/1615-acti-9-surge-protection-devices-spds/​

SIEMENS https://www.siemens.com/us/en/products/energy/low-voltage/surge-protection-devices.html ​

Note: SPDs come in a WIDE variety of installation types (din rail, side mount, flush mount, bus mount, etc.) as well as various ratings for specific applications. No matter which type you need, it must be listed.​

Note also that Types 3, 4, and 5 if are a recognized component they are not intended to be installed in the field, they are intended to be part of a listed assembly with the conditions of acceptance met.

 

62. Is it required that both 125-volt, 15 & 20-ampere and 125/250-volt generator integral receptacle outlets supplied by 15 kW or less, unbonded generator have GFCI protection for personnel? Are there other options?

Answer: Yes and yes

References: 445.20, 590.6, phone a friend

445.20 GFCI Protection for Receptacles on 15-kW or Smaller Portable Generators

Receptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed GFCI for personnel integral to the generator or receptacle as indicated in either 445.20(A) or (B):

(A) Unbonded (Floating Neutral) Generators.

Unbonded generators with both 125-volt and 125/250-volt receptacle outlets shall have listed GFCI protection for personnel integral to the generator or receptacle on all 125-volt, 15- and 20-ampere receptacle outlets.

Exception: GFCI protection shall not be required where the 125-volt receptacle outlets(s) is interlocked such that it is not available for use when any 125/250-volt receptacle(s) is in use.

Phone A Friend:

That’s a trick question.The use of a portable generator is always a temporary installation, so the requirements in 590.6(A)(3) modify the language in 445.20.  Since the manufacturers of portable generators all state to operate the generator outdoors in their instruction manuals, the generator receptacles also have to be a listed WR type and protected by a hinged cover or outlet box hood since outdoors is a wet location. 

I don’t have pictures because there is no such thing as an NEC compliant portable generator because the NEC doesn’t require portable generators to be listed. 

Section 1204.2 of the IFC require portable generators that were manufactured after 1/1/21 to be listed to UL 2201 for CO shutdown, but 99% of the available portable generators don’t meet that requirement either!

590.6(A)(3) GFCI for Personnel- Receptacles on 15-kW or less Portable Generators

All 125-volt and 125/250-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed GFCI for personnel. All 15- and 20-ampere, 125- and 250-volt receptacles, including those that are part of a portable generator, used in a damp or wet location shall comply with 406.9(A) and (B). Listed cord sets or devices incorporating listed GFCI protection for personnel identified for portable use shall be permitted for use with 15-kW or less portable generators manufactured or remanufactured prior to January 1, 2015.

63. Our company recently installed some photovoltaic powered exterior signs does this require inspection, would both Articles 600 & 690 apply?

Answer:

Yes, the installation of an electric sign will require an inspection for compliance with the applicable parts of Article 600 and Chapters 1-4. The answer on if Article 690 applies will depend on whether the PV components to power the sign are part of the listed sign assembly in accordance with 600.3. Section 90.7 clearly states that the intent of the NEC is that factory-installed internal wiring, or the construction of equipment is not required to be inspected at the time of installation, except to detect field alterations or damage, if the installed equipment has been listed by a qualified electrical testing laboratory. UL 48 Electric Signs and UL 8801 PV Luminaire Signs cover the internal wiring and manufacturing of the sign, not the NEC. The PV powered sign would be a Stand-Alone System under Article 710 and would meet the definition of separately derived system.

If a separate PV system independent of the sign is being installed to provide power to the sign, then Article 690 would apply, and if the PV system was the sole source of power, Article 710 would also apply.

 

64. What UL standard would be utilized to evaluate and certify energy management systems?

Answer: The basic categories energy management systems is Energy Management Equipment category code PAZX and uses UL 916, the Standard for Energy Management Equipment or UL 60730-1, “Automatic Electrical Controls – Part 1: General Requirements.”.  The UL guide information for PAZX states:

This category covers energy management equipment that energizes or de-energizes electrical loads to achieve the desired use of electrical power. This equipment normally controls electrical loads by responding to sensors or transducers monitoring power consumption, by sequencing, by cycling the loads through the use of preprogrammed data logic circuits, or any combination thereof.  This category also covers controls and components that may form part of building automation systems or subsystems.

Another type of energy management system is Certified (Listed) under the product category Power Control Systems (PCS) under the category code QIJE and uses UL 3141, “Outline of Investigation for Power Control Systems”.  The UL guide information for QIJE states: A PCS is a specific type of Energy Management System (EMS) which electronically limits or controls current or power to stay within defined limits. PCS may consist of a single device or multiple devices operating together as a system. The current or power measurement reference point(s) may be located internally to equipment or externally within the system. All elements of the PCS are intended to be installed in accordance with the National Electric Code (NEC). Section 705.13 in the 2020 edition or section 750.30 in the 2023 edition.

The PAZX or QIJE UL guide information and Certifications (Listings) can be found on UL Product iQ at www.ul.com/piq, enter PAZX or QIJE at the search field.

 

65. If tap conductors are protected under short-circuit conditions when short-circuit temperature limits are not exceeded, does the NEC possess a calculation method to determine conductor heating under short-circuit conditions? What conditions or in what occupancies would this be allowed by code?

Answer: 240.90 General.

Overcurrent protection in areas of supervised industrial installations shall comply with all of the other applicable provisions of this article, except as provided in Part VIII. Part VIII shall be permitted to apply only to those portions of the electrical system in the supervised industrial installation used exclusively for manufacturing or process control activities.

 240.92(B) Part VIII. Supervised Industrial Installations

240.92 Location in Circuit.

An overcurrent device shall be connected in each ungrounded circuit conductor as required in 240.92(A) through (E).

(A) Feeder and Branch-Circuit Conductors.

Feeder and branch-circuit conductors shall be protected at the point the conductors receive their supply as permitted in 240.21 or as otherwise permitted in 240.92(B), (C), (D), or (E).

(B) Feeder Taps.

For feeder taps specified in 240.21(B)(2), (B)(3), and (B)(4), the tap conductors shall be permitted to be sized in accordance with Table 240.92(B).

Table 240.92(B) Tap Conductor Short-Circuit Current Ratings
Tap conductors are considered to be protected under short-circuit conditions when their short-circuit temperature limit is not exceeded. Conductor heating under short-circuit conditions is determined by (1) or (2):
(1) Short-Circuit Formula for Copper Conductors
(I2/A2)t = 0.0297 log10 [(T2 + 234)/( T1 + 234)]
(2) Short-Circuit Formula for Aluminum Conductors
(I2/A2)t = 0.0125 log10 [(T2 + 228)/( T1 + 228)]
where:
I = short-circuit current in amperes
A = conductor area in circular mils
t = time of short circuit in seconds (for times less than or equal to 10 seconds)
T1= initial conductor temperature in degrees Celsius
T2 = final conductor temperature in degrees Celsius
Copper conductor with paper, rubber, varnished cloth insulation, T2 = 200
Copper conductor with thermoplastic insulation, T2 = 150
Copper conductor with cross-linked polyethylene insulation, T2 = 250
Copper conductor with ethylene propylene rubber insulation,

 

66. Is there a limit to the number of 125-volt receptacles that can be installed within office furnishing type installation of freestanding wired partitions?

Answer: Yes, see Section 605.9(C) below.

(C) Receptacle, Maximum.

An individual office furnishing or groups of interconnected individual office furnishings shall not contain more than 13 15-ampere, 125-volt receptacles. For purposes of this requirement, a receptacle is considered (1) up to two (simplex) receptacles provided within a single enclosure and that are within 0.3 m (1 ft) of each other or (2) one duplex receptacle.

67. Is it a fireplace, or an electric heater? No, I am not referring to the new game show, many fireplaces I see installed are simply electric heaters, not a fireplace. When do these “fireplaces” break the wall space requirements for receptacles found in Section 210.52(A)(2)(1)?

Answer: If they are listed as an electric fireplace or a direct vented fireplace yes, you would treat them as a fireplace. ​

References: 110.3(B), 422.6, 424.6​

If they are listed as a fixed room or space heater, then I certainly would treat it as a fireplace/heater depending on the size and shape​

Most importantly, what do the instructions say? ​

We must always *READ* *UNDERSTAND* and *FOLLOW* the instructions. ​

These may include requirements to keep cords away, to not mount over receptacles, etc. ​

Common sense has to prevail here! ​
Where is it likely the user would need a receptacle? ​
Is there adequate wall space without counting the alleged fireplace?

 

68. Would the NEC prohibit a transformer disconnect from being remote? What if the transformer was a listed Class 2 or 3 power source?

Answer: No and no

References: 450.1, 450.14, 725.127

450.1 Scope

This article covers the installation of all transformers other than the following:

(4) Transformers used with Class 2 and Class 3 circuits

450.14 Disconnecting Means

Transformers, other than Class 2 or Class 3 transformers, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable open in accordance with 110.25, and its location shall be field marked on the transformer.

Enhanced Content:

The requirement for a disconnecting means is especially important in installations utilizing the requirements of 240.21(B)(3) where several transformers in different locations could all be tapped from one feeder, and it would be impractical to de-energize the feeder to work on one of the transformers. The disconnect is required to be located within sight from the transformer but may be in a remote location if it is lockable. The location of any remote disconnect is required to be marked on the transformer.

 

69. Does this EVSE require GFCI protection? The specifications indicate a residual current detector, same difference, right?

Answer:

Maybe to the first question and No to the second one. For cord and plug connected EVSE, Section 625.54 requires all receptacles for the connection of EVSE to be Class A GFCI protected which is a permitted modification of the requirements in 210.8. For other than cord and plug connected EVSE, we need to read the list of locations in 210.8 (F) to see if the installation meets one of 3 list item locations. List item 1 covers any outlet rated 150V of less to ground and 50A or less that is in a garage with floors at or below grade level.

So, if this EVSE is installed in a garage it will still require Class A GFCI protection for the outlet.

All listed EVSE are required to have a listed system of protection against electric shock of personnel that is listed to UL 2231-1 or UL 2231-2 Personnel

Protection Systems for Electric Vehicle (EV) Supply Circuits Parts 1 and 2.

Those systems provide protection for the output cable and vehicle connector, but do not provide any upstream protection for the EVSE outlet or branch circuit, and are not Class A GFCI devices.

Stay tuned for the 2026 NEC which requires GFCI or SPGFCI for most EVSE Installations.

 

70. Do the cables supplied from a Class 4 transmitter need to comply with 300.22(C), where located in a plenum space? Section 722.3(C) references power-limited circuits, are Class 4 circuits power limited?

Answer: New to the 2023 NEC is Article 726, Class 4 Fault Managed Power (FMP) Systems. These new systems use a transmitter and receiver together with a specific listed Class 4 cable to distribute Class 4 power between the transmitter and receiver. There are limits as to voltage and in the case of a fault, the systems cut power in milliseconds to prevent harm to people or property.  Regarding the question about the application of 300.22(C), yes it applies.  Article 726 covers Class 4 Fault Managed Power Systems.  NEC 726.3 states: Other Articles.

The listing and installation of cables for Class 4 circuits shall comply with Article 722. Only those sections of Article 300 referenced in Article 722 shall apply to Class 4 circuits.  722.3(C) addresses compliance with 300.22.  It references Power Limited cable in ducts or plenums Class 4 is not power limited but 300.22(B) is referenced.  I think they overlooked the Class 4 when they transferred other cable requirements into Article 722.

Regardless of whether or not Class 4 cable is power limited or Section 90.3 for the layout of the NEC tells us Chapter 1 through 4 apply generally and 5 through 7 modify or add to them. They are not exempt from the general rules.

Fault managed power systems are different than power limited. The transmitter and receiver and cable must be certified for use together; the system is Listed for compliance with UL-1400-1 Outline of Investigation for Fault-Managed Power Systems. and the cable is required to be certified to UL 1400-2 – Outline of Investigation for fault managed power systems – Part 2 Requirements for Cables. These are new products and systems which means everyone may need additional training to recognize and properly review, install, inspect and use them.

Class 4 power systems are Certified (Listed) under the UL product category Fault Managed Power Systems- Class 4, category code DLQC.  Class 4 cable is Certified (Listed) under the product category Class 4 Cable, category code DLPY.  Both categories UL guide information and certifications can be viewed on UL Product iQ at www.ul.com/piq, enter DLQC or DLPY at the search field.

 

71. I am an inspector who needs help verifying the instantaneous trip setting of a 1200-ampere frame breaker. How do I verify the instantaneous trip setting is below the calculated arcing current? Where this is the method employed for arc energy reduction compliance, would a performance test be required?

Answer: Yes. 240.87(C)

Let’s address the two questions:

1. How do I verify the instantaneous trip setting is below the calculated arcing current? Answer: The method could be either the instantaneous trip setting or the breaker instantaneous override. Requires an arc flash study and 240.87 requires documentation to be available if the inspector wishes to see it.

2. Where this is the method employed for arc energy reduction compliance, would a performance test be required? Answer: Yes, See 240.87(C).

 

72. Can a single set of transformer secondary conductors be tapped in a wireway to supply two separate load centers? Refer to the customer owned transformer in the line diagram below, wouldn’t this violate Section 240.21, specifically where it states “Conductors supplied under 21(A)through (H) shall not supply another conductor except through an overcurrent protective device meeting the requirements of 240.4.”

 Answer: Maybe?  References, 240.4(F), 240.21, 240.92(C)(1), & 240.21(C)(4).  Go easy on me, I’m a first timer.

To answer this question accurately, I would need more information or make assumptions.  I’m terrific at making assumptions, more specifically making a rear end of myself.  So…  Let’s assume the secondary conductors are outside as well as the fused disconnects, the transformer is a Delta primary, Wye secondary, and the installation is not within a supervised industrial area.

Were this to be installed in a supervised industrial area, Part VIII of Article 240 provides modifications to the general requirements found in Section 240.21 that would permit the installation.  Specifically, Section 240.92(C)(1), where short-circuit & ground-fault protection are provided per one of the three list items.

Too bad my assumption did not make it that easy.  Let’s start at Section 240.4(F), in short, this Section does not permit the secondary conductors from the Delta – Wye transformer to protected by the primary device.

Section 240.21(C)(4) would apply, and we would need to comply with all the list items.

(1) The conductors are protected from physical damage in an approved manner.

(2) The conductors terminate at a single circuit breaker or a single set of fuses that limit the load to the ampacity of the conductors. This single overcurrent device shall be permitted to supply any number of additional overcurrent devices on its load side.

(3) The overcurrent device for the conductors is an integral part of a disconnecting means or shall be located immediately adjacent thereto.

(4) The disconnecting means for the conductors is installed at a readily accessible location complying with one of the following:

• • • • a.Outside of a building or structure
      • b.Inside, nearest the point of entrance of the conductors
      • c.Where installed in accordance with 230.6, nearest the point of entrance of the conductors

I would say not only does the installation violate Section 240.21 as suggested in the question, but item (2) cannot be met, as the secondary conductors do not terminate at a single set of fuses.

Longest answer ever…

I will say, if the sum of the fuse ampere ratings does not exceed the ampacity of the secondary conductors tapped in the wireway, there is really no concern, as the conductors are provided with overload protection, like Exception No. 3 to Section 230.90(A).

 

73. Would you please explain the correct use of Table 210.24(1) for tap conductors?

For example, I am an AHJ inspecting a basement finish.  The contractor has a single 20-ampere circuit supplying an individual bathroom and has utilized the exception to Section 210.11(C)(3).  The contractor then utilized 14 AWG cable from a receptacle outlet to a lighting outlet and stated, “I can do that, look at Table 210.24(1).”  Would the NEC permit these 14 AWG conductors to be protected by a 20-ampere OCPD?

Sure, I can explain that, and no, the contractor cannot protect 14 awg cable with a 20-ampere ocpd in this case.

Table 210.24(1) summarizes the requirements for circuits that have two or more outlets or receptacles, OTHER THAN THE RECEPTACLE CIRCUITS OF 210.11(C)(1), (C)(2), AND (C)(3).  The branch circuit tap conductor ampacity is governed by 210.19(D).  Let’s look at 210.19(D).

In short, the row titled taps in Table 210.24(1) simply indicates to the end user, that 14 AWG is the minimum size of branch circuit tap conductor permitted on a 20-ampere circuit, where permitted.  Is does not permit any load to tap a 20-ampere circuit with 14 AWG where the load current does not exceed the conductor ampacity.  That would be anarchy.

Where can branch circuit taps be made then?  Were Sections 210.10 & 210.19(D) permit them.  Which finally brings us to the answer.  No, the contractor cannot use 14 AWG taps in this instance, it is not permitted within Section 210.10 & 210.19(D).  Furthermore, Section 210.24 clearly states the associated Table does not apply to circuits required per 210.11(C)(1)-(3).

 

 

Christine Porter	1,7,13,19,25,31,37,43,49,55,61,67
Vince Della Croce	2,8,14,20,26,32,38,44,50,56,62,68
Brian Baughman	3,9,15,21,27,33,39,45,51,57,63,69
Tom Lichtenstein	4,10,16,22,28,34,40,46,52,58,64,70
Chad Kennedy	5,11,17,23,29,35,41,47,53,59,65,71
Chris Papp	6,12,18,24,30,36,42,48,54,60,66,72, 73