In an effort to help the electrical industry make a smooth transition into the new Electrical Code and ensure the continuity in the performance of electrical work, the Department of Buildings will be posting code interpretations on its website. Listed below are new code-related questions and corresponding interpretations by the Code Committee. The users of this list should have available the 2008 edition of the NEC and the associated NYC Amendments to the 2008 NEC , as well as (Local Law 39/11) that went into effect on March 1, 2012.
All interpretations are based on the 1999 NEC and associated NY City amendments.
Whenever there are a few sections referenced, the first one is the "lead section", and the rest are secondary sections. All the secondary sections are referenced with the purpose of offering additional clarifications.
Click a topic, or press the enter key on a topic, to reveal its answer.
Chapter 1: General (Section 110.1 to 110.79)
Greetings, regarding light fixtures does the NYC DOB accept any testing laboratory that is accepted by Osha and is on their current list of NRTL's or does the NYC DOB only accept if it is "listed" by UL as required by 110.2 110.3(B) 100 definition of listed.
Testing Organization that OSHA has recognized it as an NRTL and recognized that specific NRTL to specific tests will be acceptable.
We received an objection for factory assembled CT’s in a panelboard. The inspector objected to the CT’s being wired with #20 AWG it was too small. The CT was installed in accordance with manufacturer’s instruction and that was the proper wire size based on the CT’s current ratio and it is listed to measure AC current range 100 or 200 amp. Is the installation as described code compliant and permitted to remain?
Listed equipment is permitted to be installed in accordance with the manufacture’s instruction, see section 110.3(B).
Chapter 2: Wiring and Protection (Code Section 200.1 to 285.28)
Is it legal to extend EXISTING #14 AWG wire apartment branch circuit with #14 AWG wire when replacing existing electrical service with new electrical service?
What should the wire gage be (14 or 12) when adding an outlet to an existing #14 AWG wire branch circuit.
Number 12 AWG shall be the minimum conductor used for branch circuits’ alteration and extensions. The overcurrent protection device shall be sized to adequately protect the smallest conductor size in the circuit.
Does a laundry closet require to have AFCI protection?
This closet is dedicated for washer and dryer only, with nothing else in it.
The code states Closets requires AFCI protection, but the code does not mention laundry
in the 2014 code the added the word Landry to the requirements
The current NYC Electrical Code 210.12(B) requires AFCI protection for all closets. Laundry areas are not required to have AFCI protection.
Does the definition of a "Balcony" and/or "Deck" and/or "Porch" include a window and/or door that opens to a small space outside the building that cannot fit a person? See attachment.
Question on use of Section NEC 220.84 for multifamily residential building using VRF’s for cooling/heating.
Multifamily residential building using VRF system for cooling and heating. One (1) VRF condensing unit will be used for four (4) apartments. Individual fan coil units will be serving each apartment.
Total of 69 dwelling units. 8KW will be used for electric coking for each unit.
Can we use table 220.84 to calculate total demand on the feeder busduct serving dwelling units panels and VRF condensing units. See attached sketch.
The use of section 220.84 and table 220.84 are permitted since all required conditions are satisfied and all load are served from the same feeder busduct.
Given a R2 building with a dedicated laundry area (attachment), is it required to provide AFCI protection for the dedicated 120V, 20A laundry receptacle serving the washer in a dwelling unit? The receptacle is on a dedicated circuit with a dedicated circuit breaker.
The 2008 National Electrical Code does not include laundry areas in the areas requiring AFCI protection. There is no NYC Amendment to this code section.
The BEC inspector has issued an objection during the last inspection for not providing AFCI protection for laundry washers in dwelling units.
No. The Washer/ Dryer area doesn’t fit the scope and intent of subsection 210.12(B).
Service Switch (serving fire pump) Question:
Is the maximum distance from a Service Switch (Dedicated for Serving Fire Pump) to the main incoming electrical Service (end box) 10 feet?
A six-story residential building has a single service entrance feeding three service switches (1200A, 400A and 400A) in separate enclosures located within the same Electrical Service Room. Ground rods and a Water Main clamp are connected to a Grounding Electrode Conductor (GEC) busbar located within the Water Service Room. A single GEC is run from this GEC busbar to the Electrical Service Room.
See attached is an electrical floor plan of the 2nd floor for College Dormitories. The electrician on the job went for electrical inspection and the inspector said that all the dormitory breakers must be AFCI. However, the 2008 NEC does not mention requirements for dormitories in 210.12 or 210.18. Please advise whether or not the electrician needs to install AFCI breakers.
The attached plan clearly indicates that your dormitories include a permanent provision for living, sleeping, cooking and sanitation, hence they fit the definition of dwelling units, and AFCI protection is required by 210.12(B) “Dwelling Units”.
We are designing the electrical infrastructure for a large townhome (1200A 208Y/120V 3PH service)
NYC Amendment 215.2 indicates:
Feeder conductors shall be sized so that the maximum voltage drop at the last overcurrent device does not exceed 3 percent and the total maximum voltage drop of feeder and branch circuit conductors to the last outlet does not exceed 5 percent. The minimum feeder size feeding a dwelling unit shall be 8 AWG copper or 6 AWG aluminum or copper-clad aluminum conductors.
The lighting control system for the townhome includes 15 dimming panelboards with integral overcurrent protection. Loads for each dimming panelboard do not exceed 15A at 208V 3PH. Please confirm that #10 or #12 wiring can be utilized for feeders to the dimming panels
Yes, #10 or #12 AWG can be utilized as feeders to the dimming panel. Please that Section 215.2 is intended as a minimum feeder size for a dwelling unit.
We're taping Service Feeders ahead of the main service disconnected switch and utility meter for our FACP’s primary VAC power and the service coming in is at 277/480V 3-Phase 4-Wire at 4000A (see attached).
We’re looking to clarify which code sections in the NYCEC and NEC apply as well if the Design intent is code complain. Please refer below to our questions.
We have wired office workstations partitions (cubical) using MC cables; see attached sketch. We were issued an objection for paralleling conductors under 1/0. To our understanding; the installation are branch circuit conductors and not paralleled feeders. Is our understanding correct?
The installation described and shown on your sketch is not for multiwire branch circuits as permitted by section 210.4. Multiwire branch circuit shall use one grounded (neutral) conductor and the neutral conductors in the 2-wire circuits are arranged in parallel.
Does a receptacle outlet outside of a bathroom and within 6 ft. from the edge of the sink require GFCI protection?
No, the receptacle outlet is outside of the bathroom and subsection 210.8(A)(1) is not applicable.
We are rewiring Central Park Belvedere Castle (castle on the rock). The Castle served by an existing feeder in RGS conduit connected to the site distribution power in a manhole approximately 200 feet away (see attached). We have provided Grounding Electrode to the building by connecting to the existing metal undergoing water pipe, such ground electrode requires to be supplemented in accordance with section 250.53(D)(2) and we can't install ground rods. There are no building steel or other available metals that can be used. Is it permissible to be the electrical feeder metal conduits for the supplemental?
Yes, subsection 250.52(A)(5) permits the use of such as grounding electrodes and shall comply with 250.53 (A) and (G) and 250.56.
We are installing an 800-amp trans-S cabinet and connecting to 1200-amp service switch with 2 sets of 500kCMIL. The 1200-amp service switch is being fused at 800 amp. Is full copper, 3 sets of 600 kCMIL required to connect the meter to the service switch?
Where the service switch is 1200 amp and fused at 800 amp. It is permitted that the service conductor to be sized in accordance with the calculated load in accordance with Article 220 and the feeder is protected by section 240.4(B).
Chapter 3: Wiring Methods and Materials (Code Section 300.1 to 398-104)
Is there a limit to the length a class 2 cable can be supported by a raceway? (Example: class 2, 0-10V dimming control)
NYC Electrical Code limits the length of Class 2 cable supported by a conduit to the maximum length of conduit that contains the power circuit for associated equipment it controls.
When using a listed transition fitting similar to a "Bridgeport 4057-DC or 4157-DC transition coupling", is there a length limit to a cable assembly outer armor being removed?
NYC Electrical Code doesn’t specify a limit.
I have enclosed a sketch where my question and illustration is posed, please review.
In compliance with Article 310 , Section 310.4 (B), can the feeder be extended from the manhole in the ground to the splice box as indicated on the sketch provided?
Yes, where all connections and splicing are in accordance with 310.4(A).
Is EMT conduit permitted to be installed in damp locations (e.g. a covered loading dock within a building)?
No. Section 358.10(C) and 358.12(7) do not permit EMT to be installed in Wet Locations but permits EMT to be installed in damp locations. Your example of a covered loading dock within a building doesn’t meet the definition of Wet Location.
We have an installation where the Device Specification is UL listed For Plaster, Gypsum, and solid surface
installation. The design team is looking to install these devices into wood panel walls and cabinet locations. The devices do not employ a throat or adapter plate that seems to make the device non compliant to Section 314.20
Devices are Bocci Electrical Components receptacles
See attached. The device plate gets mounted behind the solid surface, (or wood panel) and the device slides through the wall side and attached to the device plate via a internal clip. Removal of devie requires "special tool" provided with devices. As you can see in the photo the device will be flush with the wall/cabinet finish but the cutout where the devices slides through to the plate and box are unprotected.
Question: Is this an approved installation in NYC code. The residence we are installing them will have All
receptacles as this type, and corrections after completion will not be an easy fix.
No. This product is not acceptable to be installed in NYC for the following concerns;
As per National Electrical Code 300.21 (Spread of Fire).
When a Master Electrician is awarded a job in NYC for installation of an electrical system of conduits, cable, supports and fire stopping is this Master Electrician required to complete the entire job without sub-contracting any portion of the job except to another Master Licensed Electrician.
Yes. Since this work is covered under NYC Electrical Code section 300.21; only NYC licensed electricians are permitted to do electrical installation. Electrical work by unauthorized persons is prohibited by NYC Administrative Electrical Code section 27-3017.
An exception in Article 368.17(B) allows in industrial establishment only, omission of overcurrent protection at points where busway is reduced in ampacity, provided that length of the busway having the smaller ampacity does not exceed (50) feet.
The definition of industrial establishment is not provided in the electrical code. Please provide an interpretation where an office building (B occupancy group) where a busway installed in electrical closet qualifies as an industrial establishment. Else, please provide a definition for industrial establishments that would be applicable to the electrical code.
Occupancy Classification are defined in NYC Building Code. Your B occupancy is a business and the exemption is not applicable to you project.
We have a set of two parallel feeders in EMT fed by a 600A OCPD. As per 250, 122 the ground for a 600A OCPD is a #1 Copper. Each of the two EMT feeders contains a full size #1 copper ‘equipment grounding conductor’ as per 250.122. Upon inspection we received an objection on these #1 grounds, the objection referenced that we were paralleling conductors smaller than 1/O. We believe this objection was issued in error.
Question: In a parallel feeder is it permissible to have an equipment grounding conductor in each conduit that is sized in accordance with 250.122 smaller than 1/O?
Section 310.4, Conductors in Parallel is applicable to ungrounded and grounded conductors only. Equipment Grounding Conductors when installed in parallel shall comply with section 250.122(F) and sized in accordance with Table 250.122.
Chapter 4: Equipment for General Use (Code Section 400.1 to 490.74)
We have renovated large dwelling unit and installed a main lug only, 200-amp electrical panel with 60 circuit breakers. The service disconnecting means is located in the basement. Are we in violation with NYC Electrical Code section 408.36, Exception2, and the panelboard shall have a maximum of 42 overcurrent devices?
Since your panelboard has one set of overcurrent protection device, then section 406.36 Exception 2 is not applicable.
We are installing a heat trace system with control panel that has GFPE protection. Does the branch circuit to the controller required to be protected upstream with GFPE circuit breaker?
No, The Equipment Ground Fault Protection at the controller provides the required equipment see 427.22.
Chapter 5: Special Occupancies (Code Section 500.1 to 590.7)
A cable manufacturer claimed that VitaLink MC cable is permitted to be used in Hospitals for the emergency system in NYC.
Based on our understanding of the NYC Electrical Code article 517.30, flexible metal raceways and metal sheath cable assemblies are allowed for emergency feeders only in areas indicated on 517.30(3)(3).
VitaLink is of a metal sheath cable assembly type MC. We feel that this product can only be used under any of the 4 conditions listed; otherwise, it should not be used. For example, VitaLink MC cables should not be used for the non-power limiting cables to a fire alarm control panel.
Are VitaLink MC cables acceptable for use in Hospital for critical branch and life safety feeders?
Is “Vitalink MC” where installed as a feeder, considered mechanically protected to satisfy section 517.30?
Would installation of Vitalink MC be acceptable where installed as a line side feeder to a panelboard serving EES loads in a functioning Hospital, class I-2 occupany?
Code section 517.30 states:
517.30 Essential Electrical Systems for Hospitals. (C) Wiring Requirements.
(3) Mechanical Protections of the Emergency System.
The wiring of the emergency system in hospitals shall be mechanically protected. Where installed as branch circuits in patient care areas, the installation shall comply with the requirements of 517.13(A) and (B). The following wiring methods shall be permitted:
(1) Nonflexible metal raceways. Type MI cable, or Schedule 80 PVC conduit. Nonmetallic raceways shall not be used for branch circuits that supply patient care areas.
No. Mechanical protection for feeders are required by section 517.30(C)(3). Since your product is listed as an MC cable, it is only permitted to be installed in accordance with 517.30(C)(3)(3).
Chapter 6: Special Equipment (Code Section 600.1 to 695.14)
In a R-3 building (single-family townhouse) equipped with a sprinkler booster pump not exceeding 30HP, located in the cellar level, and serving sprinklers only:
We are replacing existing Power Distribution Units for a customer in a data center space where there is an existing Emergency Power Off system. We reviewed the existing space and determined that the installations in the space meet the requirements of the primary chapters of the NEC and did not take advantage of the allowances of Article 645. We would like to ask the Committee the below:
We are designing a balanced power isolated grounding system.
NYC EC 647.7 (A) (4) indicates:
(4) All 125-volt receptacles used for 60/120-volt technical power shall have a unique configuration and be identified for use with this class of system. All 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlets and attachment plugs that are identified for use with grounded circuit conductors shall be permitted in machine rooms, control rooms, equipment rooms, equipment racks, and other similar locations that are restricted to use by qualified personnel.
In areas where non-qualified personnel have access (in this particular case this is a recording studio utilized by non-qualified personnel) will the following be considered receptacles with a “unique configuration”?
620.37 Allows wiring for fire detection system to be located in the hoistway.
How has DOB interpreted this?
While the elevator was being renovated the elevator mechanic found this existing wiring inside the hoistway. I am now being asked to re-support this cable to the wall, exposed open with no conduit.
Before I inherit this project, I want to know if DOB has any objection based on 620.37 or the building code?
I do no know if this is circuit integrity cable per amendments 760.53.
Answer 1 and 2, only wiring for signal or communication including fire alarm that are used directly in connection with the elevator (cab) are permitted. Wiring for signal or communication or fire alarm passing thru the elevator shaft are not permitted.
Existing approved electrical installations is permitted to remain.
Chapter 7: Special Conditions (Code Section 700.1 to 770.182)
NEMA Bulletin #112 October 2017 (attached) explains selection and installation of type "MC-PCS" cable and its acceptance as per Article 725.136(I)(1).
U.L. 1569 Certification Requirement Decision dated 2014-12-19 (attached) explains the "Rationale For Decision" concerning MC-PCS cable. (Jacket thickness and conductor insulation rating) (industry manufactured standard is 30 mil and 1 pair 16 awg TFFN)
Article 725.136(I)(2) allows Class 2 or 3 circuits to be run in same raceway as light and power, etc. when separated by permanent and fixed non-conductor.
Can a non-conductive jacketed cable with a minimum jacket thickness of 30 mil and 600 volt rated conductors be installed in a raceway with light and power conductors and used as a class 2 circuit as per Article 725.136(I)(2) (i.e. Type TC-TFFN)?
No. Unless cables are listed for such installation.
We are in the design phase of a large campus centralized multi generator plant, distributing EM and standby power to various campus buildings via a paralleling switchgear.
The NYC Amendment to the NEC in section 700.10, (D) states; Fire system pumps or fire protection pumps requiring connection directly to the emergency generator as defined in the New York City Construction Codes shall be connected as follows: (1) Circuits supplying fire system pumps shall be connected directly to the emergency generator with only one over-current protective device which shall be rated at not less than 150 percent and not more than 600 percent of the pump full load current. (2) Where multiple generators are paralleled, the connection for the fire system pumps shall be taken from the generator paralleling bus. This causes a requirement for a separate emergency Fire Pump feeder to each building.
The NYC Amendment to the NEC in section 760.41, (D), (2) states; (2) The primary and secondary power source shall each be provided with a means of disconnect from the fire alarm system. Each disconnect shall consist of a fused disconnect switch, locked in the ON position and the key shall be kept on premises and made accessible only to authorized personnel. Such disconnect shall be painted red and permanently identified as a fire alarm circuit and labeled as to system/location served, with a means of interrupting the unfused grounded and all ungrounded conductors. This causes a requirement for a separate emergency Fire Alarm feeder to each building.
Similar to the way normal power is distributed to each building, for the sake of simplicity and economy, can a single EM/Standby feeder be distributed to each building, where it would be separated into an emergency fire pump feeder, an emergency fire alarm feeder, a required standby feeder and an optional standby feeder, utilizing a primary building over-current device (a lockable fused switch for fire alarm and an appropriately sized device for the fire pump), at the building perimeter? Does it make a difference if the EM power is transmitted at 480V or 4160V?
One emergency feeder is acceptable to provide backup to all emergency loads listed in your inquiry when installed in accordance with NYC Electrical Code. Transforming power down to utilization voltage is acceptable.
Contract drawings reflect to remove the existing copper tie between the existing service switch and existing switchboard bus. Extend the service load conductors to an ATS, MTS and then back to the switchboard. Please see attached riser. The following are our questions:
Note, the electrical modification shall be evaluated by an NRTL and assuming the alternate power source is an Optional Standby System, grounding is addressed, then our responses are as follows;
Please confirm Article 358 (EMT) is an acceptable means for protecting non power limited circuits.
No. EMT is not one of the acceptable wiring methods in section 760.46, but the Department will accept EMT for NPLFA for installation other than the following;
Regarding to fire protection on emergency feeder circuit wiring – NEC 2008 – 700.9(D)(1)(1), please clarify on the following statement, “To be installed in spaces or areas that are fully protected by an approved automatic fire suppression system.”
If I have emergency feeders running above the suspended ceiling, but the area has sprinkler coverage with heads pointing down. Does the area above ceiling also needs to be sprinklered too, in order to considered “fully protected”?
Space above the acoustical ceiling is not considered protected by the sprinklers below the ceiling. See the requirements for concealed spaces in NFPA 13 and the commentary in NEC 2014 Handbook under subsection 700.10(D)(1)(1).
Chapter 8: Communications Systems (Code Section 800.1 to 830.179)
With the reduction in lighting fixture power requirements, as a result of the advancement of LED technology, the ability to use network switches as a power supply for lighting fixtures is a reality. There are existing installations in NYC and the interest in pursuing this type of distribution is growing.
Accordingly, if a new building is planning for LED fixtures to be served from the Power over Ethernet (PoE) ports of a network switch, then the electrical design will be revised to eliminate power panels that previously were included as part of the building distribution to support the lighting system.
With this advent of POE lighting via network switches, there new Code related questions have arisen, for which we are seeking direction:
We failed an electrical inspection as follows, “Fail GND Communication equipment and equipment and cable install in electric room 800.133” Code attached. The room is presently labeled as an IT/Elec room an currently consists of a rack with communications equipment and cabling, fire alarm panel, lighting control panel, and (3) supporting panelboards. The panel boards, (3) 208/120V branch circuit panels, are not dedicated to serving IT loads only within the server room. This room does not have typical attributes of the dedicated electrical closet/room – substantial electrical distribution equipment, vertical risers, bus ducts, transformers, distribution panels, or high voltage panels, as defined by Section 110.25. Thus, we do not qualify the space as an electrical closet but as an IT room similar to a typical mechanical room with electrical distribution panels in the same space.
We believe that the room does not meet the definition of electrical closet. Can the above equipment all be located in the same room per 800.13(D) Communications equipment and cabling shall not be installed in electric closet.
The described room is not an electrical closet.
We are building a new building in NYC.
We are having a fiber optic cable pass through the main electric service room.
But the cable will be encased in ridged metallic conduit.
Is this permissible?? NYC electric code 800.133D states “not in electrical rooms”
Administrative: General Requirements
Copies of the NYC 2011 Electrical Code (only the amendments to the NEC 2008 Electrical Code) and the New York City Electrical Code (the amendments and the NEC 2008 Electrical Code) can be purchased at the CityStore.