2016 Code Revision and Interpretation Committee Code Interpretation (Last Updated: February 8, 2019)

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)

Section 110.25 - (6/1/2016)

  1. As part of a NYCHA's Hurricane Sandy Resiliency program, we are replacing and elevating existing electrical service and distribution equipment in the main electrical rooms to mutli-family housing buildings that were constructed during the late 1950's. Some of the building's main electrical service room share space with existing gas service and gas meter and also security system equipment for the main lobby door access and surveillance cameras. We previously issued an ED76 form for the same project verifying that the existing low pressure gas service for cooking can remain in the same room as the electrical service. The response was "yes, when the gas service in not a high pressure gas service. The required clearance must be verified with the utility company."The existing security panel is being replaced with a new panel. The new security equipment is for surveillance cameras and main lobby door access (power supplies and network connections). Per section 110.25:
      1. Can the security panel that is being replaced and upgraded remain in the shared gas and electrical room?
        Yes, if original work was inspected and approved.

    1. In cases where the existing security equipment is located in a dedicated electrical room, can the security panel that is being replaced and upgraded remain in the dedicated electrical room?
      See No. 1.

Section 110.25 - (10/5/2016)

  1. As part of a NYCHA's Hurricane Sandy Resiliency program, we are replacing and elevating existing electrical service and distribution equipment in the main electrical rooms to mutli-family housing buildings that were constructed during the late 1950's. Some of the building's main electrical service room share space with existing gas service and gas meter and also security system equipment for the main lobby door access and surveillance cameras. We previously issued an ED76 form for the same project verifying that the existing low pressure gas service for cooking can remain in the same room as the electrical service. The response was "yes, when the gas service in not a high pressure gas service. The required clearance must be verified with the utility company." The existing security panel is being replaced with a new panel. The new security equipment is for surveillance cameras and main lobby door access (power supplies and network connections). Per section 110.25:
      1. Can the security panel that is being replaced and upgraded remain in the shared gas and electrical room?

    1. In cases where the existing security equipment is located in a dedicated electrical room, can the security panel that is being replaced and upgraded remain in the dedicated electrical room?
      No. The section 110.25 permits limited system to be installed. Refer to 770.133(D), 800.133(D), and 820.133(D), and 830.133(D).

Section 110.26(C ) - (10/5/2016)

  1. Are we allowed to install 1200A electrical service in Subcellar if there is only one exit/entrance from Cellar through hatch installed on slab in Cellar. Attached please find three (3) blue prints with new service location.
    Yes. The electric room or space must allow unobstructed egress from the working space in accordance with section 110.26(C)(1), in addition, equipment with OCPD 1200 amp and larger shall comply with section 110.26(C)(3) where personal door within 25 ft. of edge of the working space must open with the direction of egress and be equipped with panic bars or hardware. Please note that your equipment as indicated on attached plans don't comply with subsection 110.26(E), headroom requirement.

Section 110.26(F)(1) - (2/3/2016)

  1. Question is regarding Dedicated Electrical Space, sub-section 110.26(F)(1)(a), adding electrical equipment above or below existing equipment that either the existing or the new equipment will be within the dedicated electrical space.
    Because the code mentions foreign systems (piping, ducts leak detection etc.) are not allowed and doesn't specifically mention whether other electrical equipment (panelboards, transformers, switches etc.) are or are not allowed in this space the following questions have arise. Condition that raised this question is as follows: there is an existing transformer ceiling/wall mounted at a height of 9' to the bottom of the transformer.
      1. Does the transformer require the dedicated space as per (F)(1)(a)?

    1. Can the following electrical equipment some of which require dedicated elec space be installed under this transformer were the 6' dedicated space above will not be maintained.
        1. A 6" deep panelboard that is not connected or part of the transformer?
          Yes, where the head room is maintained.

        1. A panelboard that is either connected to the line side or load side of the transformer?
          See i.

      1. A Disconnect switch that is either connected to the line/load side or not part of transformer at all nor required as per the exception noted under (F) in the code?
        See i.

Chapter 2: Wiring and Protection (Code Section 200.1 to 285.28)

Section 210.52(A) - (2/3/2016)

  1. Section 210.52(A) outlined required receptacle spacing for dwelling unit such that no point measured horizontally along the floor line in any wall space is more than 6 ft from a receptacle outlet. It also defined wall space in 210.52(A)(2) as any space 2 ft or more in width and unbroken along the floor line, space occupied by fixed panels in exterior walls, and space afforded by fixed room dividers. The NEC handbook includes the following in section 210.52(A) "The word usable does not appear at all in 210.52 as a condition for determining compliance with the receptacle spacing requirements. As an example, to correctly determine the dimension of the wall line in a room, the wall space behind the swing of a door is included in the measurement. This does not mean that the receptacle outlet has to be located in that space, only that the space has been included in the wall-line measurement."
      1. Does an opening in floor (doorways, fireplaces and similar openings) resets the receptacle placement requirement such that each unbroken wall space is considered as an individual separated wall spaces and that receptacle is needed in each individual separated wall space?

      1. A wall is separated by (2) doors such that the wall space between the doors is 2'-0", does this section of the wall required dedicated receptacle? Does a receptacle 1'-0" from the edge of the other side of either door meets the intent of the code such that any point on the 2'-0" wall is no greater than 6'-0" along the floor line from a receptacle?
        Yes. This is a separate wall space and requires a receptacle. No, a receptacle that is 1'-0" from the edge of the other side of either door doesn't meet the code intent.

      1. A wall include a bump out in the center, the bump out is measured along the floor line such that is it 1'-0" depth and 2'-0" width. The walls to the left and right of the bump out are 4'-6" each. Is 1'-0" depth floor lines required in the wall space calculation as it is less than 2'-0"?

    1. A receptacle is place 1'-0" away from the handle side of the door opening. The wall space for the wall behind the door swing is 2'-0". Is a receptacle needed on the 2'-0" wall?
      Yes, if the wall space in question is a separate wall space.

Section 210.52(B) - (2/3/2016)

  1. We have an existing multifamily building constructed around 1970 with only (1) one appliance 20A branch circuit for the kitchen countertop receptacles in each dwelling unit.
    We are replacing the kitchen cabinets, installing one new outlet for the gas stove and replacing the existing (Federal pacific) apartment panels. The existing apartment feeders will not be upgraded. Based on the aforementioned scope of work:
      1. Is a new 120vac 20A appliance branch circuit required in the kitchen?
        No, if only the kitchen cabinet being replaced in-kind (no reconfiguration of kitchen layout).

      1. Are new outlets required to be installed to serve existing countertop to meet current code standards?
        See answer to a.

      1. Can the existing appliance branch circuit be extended to serve new gas stove receptacle?

    1. If the answer to question #3 is NO, can the existing raceway for the existing appliance branch circuit be used to run new 20A branch circuit to serve new gas stove outlet?

Section 210.52(C) - (4/6/2016)

  1. Question pertains to new construction of a dwelling unit in a high-rise (70 story) residential (R-2) building in Manhattan. Specifically referring to the code requirement for receptacles required on an island countertop space. Does the receptacle location on the (see attached) rendering and sketch comply with 210.52(C) Exception to (5), which states: Receptacles mounted below a countertop in accordance with this exception shall not be located where the countertop extends more than (6 in.) beyond its support base. Note: The receptacle has access from the side and front. From the side, the countertop extends less than 6 in. From the front, the countertop extends 2 ft.

Section 210.52(E)(3) – (12/7/2016)

  1. The comment on 2011 Amendments "Subsection 210.52(E)(3)- Delete the exception in its entirety. I interpret this to mean "regardless of SQ. FTage, a GFCI receptacle is required.
    We have small balconies that extend less than 2' out from building (roughly 180 SQ.FT) are we required to have receptacle.

Section 210.52(H) - (2/3/2016)

  1. Within the typical bedrooms, the entrance of the bedroom has a foyer/hallway 3'-6" wide of varying lengths. Is this space considered a "hallway" and does section 210.52(H) apply?
    This space is part of the bedroom, and section 210.52(H) is not applicable.

Sections 210.60 - (8/3/2016)

  1. An existing R2 occupancy, which has BEC approval, but whose outlet locations do not comply with current NYC Electric Code requirements of 210.52 (A & B) is being converted via filing an ALT1 to a R1 occupancy. Work within the existing units consists of installation of a Fire Alarm System as required for a R1 occupancy. For the project described above, must the quantity of outlets be increased to comply with 210.60, If:
      1. No additional work is done within the unit.
        This is a change in occupancy and receptacles must comply with section 210.60 and section 210.52 if such spaces are provided with permanent provision for cooking.

      1. Select receptacles are to be added to accommodate specific equipment locations. New Receptacles will be on new Arc-Fault type circuit breakers.
        See answer to a above.

    1. The existing unit panels are to be replaced such that arc-fault type protection is provided per section 210.18 for the existing receptacle circuits and any new.
      Panelboard must accommodate the requirement for the new wiring of the new work.

Section 210.60 – (12/7/2016)

  1. There is a building with a residential type J-3 occupancy. This building will be occupied by Jesuits (priests). Floors 4 thru 6 are studio rooms with bathrooms. These studios do NOT have living rooms, nor permanent kitchens within them. There are Living rooms in common areas on each floor 4 thru 6. There are 2 kitchens, 1 located on 2nd floor and 1 on 3rd floor, with dining areas next to each kitchen. All above will receive new branch circuit wiring. We are trying to determine the wiring method to use. Should this building be wired as we would
      1. a residential dwelling unit?

    1. a guest suite, guest room, dormitory etc?
    The occupancy described above is a similar occupancy to guest rooms or guest suites, and shall comply with section 210.60.

Sections 220.42 - (8/3/2016)

  1. Can microwave 1550 Wats, 1PH, 2W installed over range and fastened in place be calculated at 1500 Wats appliances line and for feeder load calculation added to general lighting load as per 220.42 by taking 35% demand factor?
    No. Such load is a part of fastened-in-place appliances load and demand factor in accordance with section 220.53 may be used.

Section 220.61 - (6/1/2016)

  1. We are performing a partial renovation to a single family dwelling townhouse where the existing risers to various sub panels throughout the dwelling have existing feeders that are fused at three phase 150 amp with 2/0 current carrying conductors and with a #4 derated neutral. We are extending the location of the riser and circuit breaker panel as well as replacing the main distribution panel from where the risers originate from. Can the #4 derated neutral remain and be fused at 150 amps?
    No. unless you provide calculated neutral loads to support your installation.

Section 230.46 - (6/1/2016)

  1. In NYC's amendment to Article 230.46, splices in service entrance cable are not permitted before terminating at the service disconnecting means, with four exceptions. When installing a Photo Voltaic System feeder to the AlC Disconnect for the Photo Voltaic System is a Line side tap (w/o splicing the service entrance conductors) permitted within the Service Disconnect equipment?
    Yes. Photovoltaic system line side tap is allowed.

Sections 230.46 - (8/3/2016)

  1. Section 230.46 Unspliced Conductors. Service entrance conductors shall not be spliced before terminating at the service disconnecting means, except for the following terminations that are permitted:
      1. In a service end line box.

      1. Taps supplying two to six service disconnecting means when grouped.

      1. Approved terminals in meter enclosures.

    1. Service-entrance conductors in the form of busway, shall be connected as required in order to assemble the various fittings and sections.
    As it pertains to this section of code, for a 3000A, 208V, 3-Ph, 4-W service entering a facility from a Con Edison vault in the street, the service entrance conductors run approx. 200' in underground duct bank from the vault to a manhole located adjacent to the building. From this vault the cables run in duct bank under the existing foundation into the buildings switchgear located in the basement. In the late 1990's a fire within the Con Ed vault damaged these cables and ultimately the section of cable from the vault to the manhole located adjacent to the building were replaced. This introduced a splice joint connection within the manhole adjacent to the building. For work being conducted now associated with this service switchgear and conductors, would this condition be grandfathered and the splice joint be allowed within the service conductors within this manhole adjacent to the building or would a service end line box or service disconnecting means need to be installed at this location to avoid the splice joint.
    Unmodified, undisturbed, permitted and signed-off electrical work can remain.

Sections 240.21(B)(2) - (8/3/2016)

  1. NYC Electrical Code Section 240.21(B)2. Taps Not over 25 ft Long says:
    "Where the length of the tap conductors does not exceed 25 ft and the tap conductors comply with all the following:
      1. The ampacity of the tap conductors is not less than one-third of the rating of the overcurrent device protecting the feeder conductors.

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

    1. The tap conductors are protected from physical damage by being enclosed in an approved raceway or by other approved means."
    We have a case on the existing project where 500KCMIL feeder is tapped off the existing 800AMP Motor Control Center bus. This tap terminates in a single set of fuses (350AMP), as indicated on the attached sketch SKE-100. Is such installation code compliant?
    No. Your equipment grounding conductor shall comply with subsection 250.122(G), and a 1/0 CU or 3/0 AL, EGC is required.

Section 250.21(A)(2) - (2/3/2016)

  1. The violation we have received states that our motor control isolation transformers are a separately derived system. NEC 2008 ARTICLE 100 - definitions - defines a separately derived system as "A premise wiring system whose power is derived from a source of electric energy or equipment other than a service". ARTICLE 100 further defines "premise wiring" with the following exceptions, "Such wiring does not include wiring internal to Appliances, Luminaires, Motors, Controllers, Motor Control Centers & Similar Equipment". Based on the above definitions, our transformer, because it is an integral part of our motor control center & motor controller, is not a separately derived system (See Figure 620.13 from the CODE), which shows, in this one line diagram, that the transformer is located after the disconnect & short circuit protection and therefore a part of our control center/motor controller. Section 250.21(A)(2); "separately derived systems used exclusively for rectifiers that supply only adjustable – speed drives" do not require grounding. In the case of elevator drive systems, the transformer secondary is directly wired to the industrial drive that controls the speed of the elevator. In addition, 250.21 A (3), also exempts separately drive systems supplied by transformers if conditions (a),(b),(c) are met. In the case of elevators it is our opinion these three conditions are met.
    Subsection 250.21(A)(2) permits a separately derived systems used exclusively for rectifier that supply adjustable –speed drives. Section 250.30 is not applicable.

Section 250.30 - (4/6/2016)

  1. We have inverter-based, CHP systems installed throughout the city. The generators operate in parallel with the grid, and also have the ability to operate in a standby capacity during a power outage. The standby loads and generator are isolated from the building during a power outage by opening the 3 phase conductors, but the neutral is solid through the entire installation and is not switched. The neutral is grounded and bonded at the service entrance. The installation consists of a permanent magnet generator feeding an AC-DC-AC inverter system. The inverter produces 480V, 3 wire power which is connected to the delta side of an isolation/step down transformer. The wye side of this transformer feeds the building at the building voltage. The building neutral is connected to the center point of the transformer, but is not grounded or bonded. This allows both single and 3 phase loads to be fed by the generator during a power outage. Recently we received a violation from an inspector for having no water main ground or neutral-ground connection on the building side of the isolation transformer, with the inspector interpreting it as being a separately derived system. While we agree that the inverter side of the isolation transformer is a separately derived system, we believe that the building side is part of the building system, and cannot meet the definition of a separately derived system as defined in article 100 because the neutral (and 3 phase conductors in grid-parallel operation) do have a direct electrical connection to the service. Is the building side of the isolation transformer a separately derived system? Should the neutral be bonded and grounded to building steel/water main at the transformer?
    No, it isn't considered a separately derived system. No, the grounding as per the provided schematic is acceptable.

Section 250.52 and 250.53 - (2/3/2016)

  1. When an underground water pipe is used as the grounding electrode, it needs to be supplemented by an electrode listed in 250.52(a)(2) through (a)(8). This eliminates the possibility of using another underground water pipe as the supplemental grounding electrode. In the past we were told in the field that the use of the sprinkler main coming into the building, when entering as separate service, was acceptable as the supplemental since 250.52(a)(8) allows "other local metal underground systems or structures". Please confirm if the sprinkler main, when entering the building as a separate service, is acceptable as a supplemental grounding electrode.
    Sprinkler water supply pipe complying with this article is acceptable, unless such metal pipe is provided with nonconductive protective material or layer. Note; removing such protective material to make contact is not allowed.

Section 250.92(B) and 250.96 - (4/6/2016)

  1. I have a question regarding whether a current installation in a new construction building is considered to be mechanically grounded. This is a building that has Con-Edison meterbanks installed on a floor. From that meter bank there is 7-wire feeder scheme to pick up (3)-vertical apartments at 208/1PH. From the meterbank to the first panel there is a ground wire that terminates on a ground lug at this first panel. So from up to the first panel the grounding is sufficient. However, after the first panel we have the following condition. There is EMT conduit that is joining the 1st panel to the 2nd panel and the 2nd panel to the 3rd panel. The EMT conduit has the same set up at each eccentric KO entering and leaving each panel for the rest of the riser. The EMT conduit has a set screw connecter, reducing washer, eccentric KO (without all the tabs removed) on the QO wide gutter load center, reducing washer, locknut & then plastic bushing. See (attached) pictures for more clarification. It seems clear per 250.92(B) that this would not suffice for a service ground without the addition of a bonding bushing and bonding jumper. However, this is not service equipment and it doesn't seem so clear in 250.96 (Bonding Other Enclosures) if this would be an approved method of mechanical grounding or if you would in fact require a bonding bushing with bonding jumper to satisfy the grounding requirements.
      1. Is this an approved method of grounding at the panel?
        Yes where listed washers are installed on non-service equipment, and all concentric and eccentric knockouts have been removed.

    1. If not would a split ring bonding bushing with a bonding jumper satisfy the requirement?
      All listed bonding material and fittings are approved when used according to its listing.

Sections 250.92(B) and 250.102(C) - (6/1/2016)

  1. The following questions pertain to the use of the ungrounded conductor for bonding in the end line box. In this instance we have an end line box feeding our main 3200 amp Service switch 200' away. End line box load has 10 parallel sets of RNC (incased in 2" of concrete) with 4x500 kcmil in each 4" PVC conduit. We intended to bond the neutral in SEB and again in our main service switch, from out Service switch to the water main and grounding electrode.
      1. Is it okay to use the ungrounded conductor (Neutral) to bond in the end line box?
        Yes. You can use the grounded conductor.

      1. Do we need to carry another grounding or bonding conductor from our Main service switch to End line box?

      1. RNC have no metal parts thus no need for a 5th ground wire, because we are on the service side.
        No, see b.

      1. When calculating the service equipment bonding jumper based on 250.102C we have 2 options. One is to calculate the total kcmil per phase (500kcmil x 10 sets x 12.5%) and only using one grounding conductor if we have a cable tray or trough.
        You may use one bonding conductor if sized in accordance with code. Note that cable tray is not permitted as a wiring method.

      1. My question is with option #2; We have 10 parallel runs as mention above we can run one 1/ort copper based on table 250.66 in each set.

    1. Or must we sum up the total Kcmil in each set/conduit) 500kcmil x 4 wires 2000kcmil x 12.5% and use the appropriate wire)?
      No, the correct calculation is 500 Kcmil x 10 x 12.5% = 625 Kcmil.

Chapter 3: Wiring Methods and Materials (Code Section 300.1 to 398-104)

Section 330.12 - (4/6/2016)

  1. All questions pertain to new construction of a high-rise (70 story) residential (R-2) building in Manhattan.
      1. Can PVC-coated MC cable be used for branch circuits if routed with a concrete slab and in a minimum of 2" concrete cover?

      1. Can MC cable be used for feeders?
        Yes, when installed in accordance with Article 330. Note, when paralleling MC cables; the grounding equipment conductor may not be adequate, and when MC cables are used in riser applications, they must be listed for such application.

    1. Can PVC-coated AC cable be used for branch circuits if routed with a concrete slab and in a minimum of 2" concrete cover?
      N/A. The product does not exist.

Sections 300.10 and 300.12 - (6/1/2016)

  1. Please confirm whether the following installation meets the NYC / NFPA Electrical Codes? Please see installation description below along with attached document and photo's. Contractor Installation Example. Contractor has conduits poking down/out through the concrete slab approximately 1" to 1 1/2" extended beyond the slab. The contractor would then cut out the bottom/back of the box to expose the conduit and concrete above, a big enough area for all the conduits to fit through the cut out into the box. The contractor would then mount the box to the slab and bonds the equipment grounding conductor to the metal box. The installation is then considered complete. With this installation unused openings are not closed, conduits are not properly terminated with connectors into the box. It is WSP's opinion that this installation meets the following codes and listings, can you confirm?
    Article 110 Requirements for electrical installation - 110.2, 110.3 & 110.12
    Article 300 Wiring Methods - 300.4
    Article 314 Outlet, Devices, Pull & Junction Boxes, Conduit Bodies - 314.40 & 314.72.
    UL-50.5 Construction General - 5.1, 5.3 & 5.5
    UL-50.6 Enclosures General - 6.1
    UL-50.8 Openings In Enclosures - 8.5
    UL-50.27 Connection For Wiring Systems - 27.1 & 27.2
    No. The conduits are not continuous as required by section 300.10 and 300.12.

Section 314.29 and Def. 100 - (6/1/2016)

  1. A 12'L x 10'W x 3'D rectangular metal pull box will be installed in the ceiling of a building lobby. The pull box will be secured to the slab above and the bottom of the pull box will consist of (4) removable access panels and (1) non-removable support strip (refer to attachment "SK-001-1"). A linear return diffuser / lighting device strip will be installed 10" below the pull box and will be located directly under the non-removable support strip (refer to attachment "SKE-001-2"). The ceiling below the pull box is removable and fully accessible except for the linear return diffuser / lighting device strip. It is WSP's opinion that neither the non-removable support strip nor the linear diffuser / lighting device strip located below the pull box, renders the wiring methods located inside of the pull box inaccessible. Is the pull box in question accessible (as applied to wiring methods) and does it meet NYC / NFPA electrical codes, particularly the following code sections? Article 314.29 - Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible
    Article 100 - Definition of "accessible (as applied to wiring methods)"
    As long the pull box cover(s) can be removed, the installation is acceptable.

Sections 352.10 - (8/3/2016)

  1. Section 352.10(J) allows the use of PVC conduits in non-residential buildings over 3 stories high provided it is concealed within non-plenum walls, floors and ceilings that provide a thermal barrier of at least one hour rating. Given a condition where PVC conduit is installed in a manner as described above, but where such system utilizes PVC junction boxes, pull boxes, or switch and receptacle boxes where the rims of such boxes are flush with the wall or floor or ceiling, would such installation meet the intent of the code? P.S. The cover plates of boxes mentioned above would be metallic.
    No. The intent of the code is to provide one hour thermal barrier between the room and the PVC.

Sections 320.10(4) & 320.12(1) - (10/5/2016)

  1. Please advise/confirm on the following as an installation method in a "ground up" health care facility in mechanical rooms. Does Art. 320.10 (1) and 320.12 (1) include mechanical rooms if armored cable (Type AC) wiring is installed above 8FT?
    Yes, as long such wiring or branch circuits are not part of the emergency system and serving patient care areas.

Sections 330.10(4) & 330.12(1) - (10/5/2016)

  1. Please advise/confirm on the following as an installation method in a "ground up" health care facility in mechanical rooms. Does Art. 330.10 (4) and 330. 12 (1) include mechanical rooms if metal clad cable (Type Me) wiring is installed above 8FT?
    Yes, as long such wiring or branch circuits are not part of the emergency system and serving patient care areas.

Section 300.3 - (12/7/2016)

  1. (4) 4.16KV Main Switchgear Substations are feeding (4) corresponding 4.16KV Distribution Switchgears MVS-1A, MVS-1B, MVS-2A AND MVS-2B (see attached single line diagram). Can the load conductors from MVS-1A, 1B, 2A & 2B share a common Pull Box without barriers between them?
    No. Secondary of transformers are not allowed to share raceways or pull boxes per subsection 300.3(C)(1)(a).

Chapter 4: Equipment for General Use (Code Section 400.1 to 490.74)

Sections 430.102(A) - (8/3/2016)

  1. We are the consulting engineers working on project in NYC downtown and would like to clarify the following: Exception No. 2 to 430.102(A) says that: "A single disconnecting means shall be permitted for a group of coordinated controllers that drive several parts of a single machine or piece of apparatus. The disconnecting means shall be located in sight from the controllers, and both the disconnecting means and the controllers shall be located in sight from the machine or apparatus."
    See SKE-100 - question 2:
    We have a case where existing Outside Air Unit was upgraded and equipped with new Fan Wall consisting of 15 fans (motors) acting as a single machine. The Outside Air Unit may deliver up to 140,000 CFM. In order to prevent any servicing attempts on single fan without the disconnecting power to the entire Outside Air Unit, individual fan motors were not equipped with individual disconnecting means, claiming exception No. 2 to 430.102(A). There is a controller and the main disconnect switch located within site from the Outside Air Unit. Based on the above please advise whether such installation is code compliant.
    Yes, where the Fan Wall Control disconnecting means capable of being located in open position and disconnects all ungrounded conductors to all the fan motors in accordance with section 430.102(B), Exception (a).

Sections 406.5(F)(1) - (10/5/2016)

  1. Is the 'Twine' corded system described below allowed for use in New York City? Per the manufacturer, the product is ETL Listed in compliance with UL 962a - 'Furniture Power Distribution Units'. The product will be permanently fixed to the underside of a bar counter in a retail space. Its outlets will be surface mounted to the counter underside & will be faced outward towards seated customers. The Bar & its associated counter will be fixed mounted to the floor. Power to the product will be provided via its standard grounded 3-pronged 120V, 15A plug & plugged into a hardwired 15A, 120V rated receptacle, supplied via a 120V, 15A rated dedicated circuit. Utilizing the 'Twine' Product, power will be provide to general convenience loads (ie customer phone/laptop chargers) & permanently installed, plug in lighting loads. Per the manufacturers specification, each plug-in Twine system will have the following:
    • Total length of the system cord will not exceed 25 Feet in length

    • Branch lengths of cord are not to exceed 6 Feet in length

    • Maximum of 6 total branches per system.

    • Each branch will terminate to a fixed, surface mounted 'Minitap' outlet.

    • A maximum of 8 power outlets total will be provided per system.
    Attached for reference:
    Manufacturer provided system cut under 'Twine'& Byrne Twine Brochure.
    Branch outlet cut 'Byrne SurfaceMount_MiniTap2.
    Excerpt from the UL White Book 2015-2016 citing the UL 962a Section
    'Furniture Power Distribution Units.'
    No. Please verify the listing of the product.

Section 406.3(D)(3)(b) – (12/7/2016)

  1. Is it acceptable in NYC electrical code to use a GFCI to replace ungrounded two prong receptacle in old buildings and label it "no Ground"?
    Yes, in accordance with subsection 406.3(D)(3)(b)

Sections 450.3(B) & 240.21(C ) – (12/7/2016)

  1. Please see attached letter for full summary of violation, as well as electrical single line. The contractor has received the following violation for the electrical installation:

    75kVA transformer: Combined OCP on secondary is greater than rated ampacity on secondary (450.5 notes)

    We believe the referenced section 450.5 may have been a typo, and that the actual objection is to section 450.3(B), note #2. In either case, we believe the installation to be code compliant, based on the following analysis. Article 450.3(B) - Primary protection has been provided through a 125 amp circuit breaker in 277/480V panel 'LP-HN'. Per table 450.3(B), only primary protection is required when the primary OCPD size does not exceed 125% of the transformer's rated current. For our 75kVA transformer, the rated current at 125% is 112.9 amps. With the allowance in table 450.3(B) note 1, we can use the next higher standard size overcurrent protection device, which gives the maximum allowed primary OCPD size of 125 amps. Since we have not exceeded this rating, secondary protection is not required, and table 450.3(B) note 2 does not apply. This satisfies all requirements for transformer protection. Article 240.21(C)(6) - We have 3 sets of secondary conductors, each serving a separate panel with a 100A MCB. Each set of conductors complies with each provision of this section, meaning no overcurrent protection is required at the transformer secondary for any of these sets. Based on the above information, we believe the installation to be code compliant. Do you believe the installation, as described, is code compliant?
    No. The primary protection only protects the transformer's secondary side only. Your OCPDs are not located at the source of power so the secondary conductor is not protected as required by subsection 240.4(F). Your transformer secondary conductors are indeed tap conductors and you must comply with the tap rules.

Chapter 5: Special Occupancies (Code Section 500.1 to 590.7)

Section 517.13 - (2/3/2016)

  1. Is the provision of section 517.13 required in a veterinarian hospital?
    No. Article 517 is for facilities that treats human.

Section 517.18(B) - (2/3/2016)

  1. Are Hospital Grade Receptacles required in a dental Facility?
    No; unless they are required by dental equipment manufacturers.

Sections 517.30(B)(3) & 517.32(C)(3) - (10/5/2016)

  1. Please advise/confirm on the following for installation in the construction of a new "ground up" health care facility on patient care floors:
      1. Can the line voltage wiring for Variable Air Volume (VAV) boxes supplied by an "equipment system" ATS and part of the "essential electrical system" powered by an alternate source (emergency generator) be wired in HFC MC or AC cabling?

      1. If the answer to question#1 is no, shall the wiring be harnessed in a nonflexible metal raceway (EMT)?

      1. Can the line voltage wiring for fire/smoke dampers (FSD) supplied by an "equipment system" ATS and part of the "essential electrical system" powered by an alternate source (emergency generator) be wired in HFC MC or AC cabling?

    1. If the answer to question#3 is no, shall the wiring be harnessed in a nonflexible metal raceway (EMT)?

Chapter 6: Special Equipment (Code Section 600.1 to 695.14)

Sections 605.6 - (10/5/2016)

    1. At one time in the NYC electrical code a junction box was required between the modular connector and the whip that connects to the branch circuit in the building for an infeed when used in Office Furnishings as noted in the NYC amendments to article 605 of the National Electrical Code. Is this still required? I have attached an example of this to the E-mail I have sent.
      A junction or splice box is required to provide access to conductor splices and limit conduit bends to 360 degrees. If your installation does not contain conductor splices or within allowed maximum conduit bens, then such splice or junction box is not required.

  1. Section 605.6 also states "where liquidtight flexible metal conduit is used, the maximum length shall be 18 inches". Typically 18 inches will not be long enough to connect to the branch circuit in the floor, wall, or ceiling. The other option is to use flexible metal conduit. Is Flexible Metal Conduit approved for use on the floor if the attachment to the branch circuit is in the floor? (Typically we use liquidtight on the floor due to spill hazards but 18 inches is typically not long enough for our applications.)
    Yes, when installation is in compliance section 605.6.

Section 695.5 - (2/3/2016)

  1. Our question pertains to using transformers to utilize 480V riser to feed 208V Fire Pumps (see sketch). The Electrical Engineer has asked us to look into taking the 208V feed for the Fire Pumps on the roof and use a transformer in the service room to step up to 480V, then use a transformer at the Dire Pump, before the controller to step back down to 208V. 695.5(A) states that secondary disconnecting and over-current is not permitted.
      1. Is the over-current device on the primary side of the second transformer considered also on the secondary side of the first transformer?
        Additional OCPD shall not be permitted to be installed in a fire pump circuit; other than the fire pump service switch.

    1. Is this installation acceptable?
      No. Use of transformers for the reason described in your inquiry and a remote service switch is not permitted under current NYC electrical code.

Section 695.6 - (12/7/2016)

  1. We respectfully request a code interpretation on the following scenario: Is it permissible to install Type RHH Draka "Lifeline" 2 hour rated cable installed in EMT conduit with compression fittings in a UL FHIT.25A assembly? This would be in lieu of MI Cable for a 2 hour rated protection for a fire pump conductor or any Emergency conductors. The feeder is a completely horizontal run except for final connections at the Fire Pump Service Switch & Fire Pump Controller? Attached herewith are the cut sheets for the cable and the UL FHIT.25a sheet for reference.
    Yes. RHH-2 is acceptable for your application horizontally for Fire Pump circuit when installed in accordance with UL FHIT system 25A.

Chapter 7: Special Conditions (Code Section 700.1 to 770.182)

Section 700.6(F),(G) – (12/7/2016)

  1. A custodial residential project on client has requested a connection for a portable generator. The client also requested a voluntarily installed complete code-complying fire alarm system for the residence. The residence has 2 separate dwelling units located on the street floor. We intend to place a NEMA 3R disconnect outdoors and for break-before-make operation, a manual transfer switch (MTS) inside the building.
      1. Can the MTS be an electrically operated switch sized to carry the entire service load?

      1. Does the fire alarm system require a separate MTS as for a required fire alarm system?
        If the optional fire alarm system was permitted to be installed, then a separate ATS may be provided.

    1. Do the MTS units have to be in a separate 2 hour rated enclosure as if they were automatic transfer switches?
      No. Optional standby are not required to have 2 hour rated enclosure.

Sections 700.10 - (10/5/2016)

  1. Is there a code requirement for an elevator feeder to be in an individual, dedicated conduit, where all feeders emanate from a common emergency distribution board?
    No, where ampacity adjustment is addressed and fire protection for emergency feeders are is provided

Section 701 and 702 – (12/7/2016)

    1. Can the one specified 300KW gas generator equipped w/two properly rated circuit breakers supply electric power two (2) individual electric loads in the case of a utility power failure?
      Yes, where the gas generator is supplying Standby and/ or Optional Standby Systems.

    1. Can both ATS switches be located in the existing service (1200A) and dist. room?
      Yes, for optional loads only.

    1. Within the existing service & dist.rm mentioned above now exist a gas hot water tank and a gas circulation hot water system both 5' or more away from the service & dist. equipment, both systems are located on the opposite wall of the electrical equipment, is this allowed?
      Mechanical equipment are allowed to occupy the same space as the electric service as long as the total electric service is less than 1000 kVA, and they don't interfere or located in the dedicated equipment space, working space, or egress, and the gas pressure is under 15 psi.

    1. The 300KW gas generator is sized as per electrical code requirements and is approved for its use to meet all NYC & NEC codes, is there any other laws that need to be addressed?
      If the gas generator is to serve Standby loads, the generator and the ATSs shall be listed in accordance with UL 2200. Contact DOB for additional construction permits required.

  1. Does all the above meet the code requirements in Chapter 27 electrical section BC 2702 emergency and standby generators and Article 11, emergency power, 27-396.4 Requirements, 27-396.5 Registration, and 27-396.6 Applicability.
    If this alternative power source is to provide emergency power to the building, then gas generators are not acceptable cor other than R-2 occupancies. Chapter 27, section 2702.1.1 does not permit gas as a fuel supply. In addition, section 2702.2.1 shall apply to the Assembly Occupancy and emergency power shall be provided in accordance with section 907. If this alternative power source is in fact Standby System ( Article 701) and/ or Optional Standby System (Article 702); then it would be allowed in accordance with sections 2702.1.1 and 2704.4 and re-identifying the loads as such.

Section 701 and 702 – (12/7/2016)

  1. Gas driven generator for both emergency and standby power.
    Proposed installation of a 300kw gas generator equipped with two (2) CB to provide electric power to an emergency panel & a house panel via transfer switches. The generator is to be mounted on an engineered certified steel structure built on a roof no more than 45 feet high.

    Building characteristics:
    • Built: 1928, OC was issued March 1st 1929.

    • 27-237 occupancy classification.

    • Occupancy group: F-4.

    • (2008 BC 303.1 equivalent A2).

    • Classification: Assembly.

    • Fire index: 1
    Per section 27-258, F-4 shall include buildings and spaces in which persons assemble for dancing or for the consumption of food or drink. The purpose of this inquiry is to make sure it meets all related codes. Does anything within Title Article 27/ subchapter 6 and or specifically Article 11 Emergency power or anywhere else in the code prevent us from installing the 300KW gas generator on the roof as submitted? Note: See attached one line diagram.
    2014 BC section 28-101.4.3 allows the optional use of previous code (1968 BC) unless the installation meets one of the exceptions, then you must follow the current building code. If this alternative power source is to provide emergency power to the building, then gas generators are not acceptable per Chapter 27, section 2702.1.1 does not permit gas as a fuel supply. In addition, section 2702.2.1 shall apply to the Assembly Occupancy and emergency power shall be provided in accordance with section 907. If this alternative power source is in fact Standby System (Article 701) and/ or Optional Standby System (Article 702); then it would be allowed in accordance with sections 2702.1.1 and 2704.4 and re-identifying the loads as such.

Section 701.10 – (12/7/2016)

  1. We are the electrical contractor bidding on a job to furnish and install an emergency lighting central inverter, no permit issued as of yet. Can the existing circuit in conduit system be split into normal and emergency as stated in electrical code Section 701.10? If no, do we have to follow section 700.9B?
    Section 701.10 addresses Legally Required Standby and not emergency circuits. The installation shall comply with subsection 700.9(B).

Section 702.5 - (4/6/2016)

  1. We are installing an Optional Standby Generator to backup sump & ejector pumps. As per 2702.4 of the 2014 NYC Building code we are required to put the fire alarm system on this generator. We are providing a separate transfer switch for the fire alarm system. Are we required to install the transfer switch in a separate 2HR rated "emergency" service room?
    This is a Building Code question and we are providing an answer as guidance only; All life safety transfer equipment are to be located out of the primary electric service room in a two hours rated enclosure.

Section 760 - (6/1/2016)

  1. A NYC Master Electrician's License is required for the installation of a Fire Alarm System as required by the NYC Administrative Code and indicated by the Department of Buildings rule 36-04. "VESDA" and "FAAST" are smoke detection aspiration systems and as such are part of a building fire alarm system. Is a NYC Master's License required for the installation of these smoke detection aspiration systems which are a component of a building Fire Alarm system.
    The installation requires a NYC Licensed Master Electrician.

Section 760.41 - (6/1/2016)

  1. Section 760.41 (B) states that "where an emergency system is provided or required to be provided for emergency system loads, the fire alarm system shall be provided with a secondary power source. Batteries shall not be a substitute for connection to a secondary power source".
    In a non-high rise (less than 75ft) Group A occupancy building where an emergency power system is required to be provided for the fire alarm system in accordance with Section 2702.2.1 of the 2014 NYC Building Code:
      1. Is a captive source (diesel) generator required to provide secondary power to the fire alarm system?
        Yes, when emergency power is required by Building Code.

    1. If the answer to 1 is 'No', can batteries be used?
      See answer to a.

Section 760.41 - (10/5/2016)

  1. There are three new high rise buildings, Building #1, Building #2 and Building #3. The buildings are approximately 800,000sf each, located on separate block/tax lots. Con Edison is providing one electrical service for all three buildings. The main electrical service is located in Building #1. Building #2 and Building #3 main switchboards, located in their respective main electrical rooms, are served from the Building #1 main electrical service. Each building has a separate and independent Fire Alarm System. Building #1 fire alarm service switch is tapped ahead of the Building #1 main service switchboard. Can Building #2 and Building #3 fire alarm service switch be tapped ahead of their respective main switchboard located in the their main electrical room? Or do they have to be tapped ahead of Building #1 main service switchboards and located in Building #1 main electrical room?
    Where the three buildings are under same ownership, have an easement to be treated as one property, a letter of no objection from the borough office, and comply with Part II of Article 225, then Fire Pump and Fire Alarm may be connected ahead of the main disconnecting means of their respective building they serve.

Section 760.130 – (12/7/2016)

  1. Regarding 760.130 Wiring Methods and Materials on Load Side of PLFA Power Source, with specific regards to what type of conductors can be run in conduit for fire alarm. "Fire alarm circuits on the load side of the power source shall be permitted to be installed using wiring methods and materials in accordance with 760.130(A), (B) or a combination of (A) and (8)" (760.130) (A) Indicates that "Conductors shall be type THHN, .'" TFN, ... " (NYC Amendment 760.48(8)) (B) Indicates that "cables shall be installed in raceway as per Article 342, 344, 358 (EMT), or 386" (NYC Amendment 760 .130(1)) Is it permissible to run PLFA wiring using THHN and TFN 600V conductors in EMT above 8' in a fully sprinkled machine room in a fully sprinkled new building?
    PLFA is permitted to be installed in accordance with 760.130(1) where 760.46 is reference as the wiring method, also applying Exception No. 1, sections 760.48 thru 760.53. Section 760.52(A) permits your proposed installation.

Chapter 8: Communications Systems (Code Section 800.1 to 830.179)

Section 800.48 and 801.2 - (6/1/2016)

  1. Article 800.48 limits the distance of an unlisted outside plant communications cable entering a building to a maximum of 50 feet. The distance is measured from the cable's point of entrance into the building. The point of entrance is defined in Article 801.2 as a the point within a building at which the cable emerges from an external wall, from a concrete floor slab, or from a rigid metal conduit (Type RMC) or an intermediate metal conduit (Type IMC) connected by a grounding conductor to an electrode. Given a condition where the length of Type RMC or Type IMC for continuing the unlisted cable from the foundation wall to a telephone service room is, for example a 100 feet, are intermediate pull boxes permitted?


Articles 517 & 700 - (10/5/2016)

  1. Per to NYC 2011 Electrical Code Article 701: "legally required standby systems. delete the article in its entirety and add FPN to read as follows: FPN: All legally required standby systems are classified as emergency systems". Per NFPA 70 (2008) Article 700.9 (B) c: "Legally required and optional standby circuits shall not originate from the same vertical switchboard section, panelboard enclosure, or individual disconnect enclosure as emergency circuits." Per NFPA 70 (2008) Article 517.30 (C) (1): "Separation from Other Circuits. The life safety branch and critical branch of the emergency system shall be kept entirely independent of all other wiring and equipment and shall not enter the same raceways, boxes, or cabinets with each other or other wiring.
      1. Is the Life Safety Branch and Critical Branch in health care permitted to originate from the same vertical switchgear section?
        No. Life Safety and Critical branches are both subsystems of the emergency system.

      1. If the circuit breakers are compartmentalized?

    1. And/if the control and power wiring is compartmentalized?
      Question not clear.

Administrative: General Requirements

Section General – Administrative - (6/1/2016)

  1. I am installing a solar of system for a customer that owns a legal 2 family home with 2 utility meters. He is requesting that we combine his 1st and 2nd floor panels by re feedings his sub panel from the 1st floor panel and , and to eliminate 1 utility meter , so that we can back feed solar power to the entire house with 1 system. Can you please clarify if this is going to change the home from a legal 2 family, to a 1 family? Will this change the c of o? And what is the proper procedure.
    What is the code for this issue according To DOB, as I cannot find the answer in the code book.
    Such installation does not change the Certificate of Occupancy, but you will be in violation with NYC Energy Conservation Code.

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.

Other Code Interpretation Links