ADOPTS WITH AMENDMENTS:

NFPA 70, 2017

Heads up: There are no amended sections in this chapter.

Part I General

This article covers the installation of conductors, equipment, and field wiring for electric signs, retrofit kits, and outline lighting, regardless of voltage. All installations and equipment using neon tubing, such as signs, decorative elements, skeleton tubing, or art forms, are covered by this article.

Informational Note: Sign and outline lighting illumination systems include, but are not limited to, cold cathode neon tubing, high-intensity discharge lamps (HID), fluorescent or incandescent lamps, light-emitting diodes (LEDs), and electroluminescent and inductance lighting.

LED Sign Illumination System. A complete lighting system for use in signs and outline lighting consisting of light-emitting diode (LED) light sources, power supplies, wire, and connectors to complete the installation.

Neon Tubing. Electric-discharge luminous tubing, including cold cathode luminous tubing, that is manufactured into shapes to illuminate signs, form letters, parts of letters, skeleton tubing, outline lighting, other decorative elements, or art forms and filled with various inert gases.

Photovoltaic (PV) Powered Sign. A complete sign powered by solar energy consisting of all components and subassemblies for installation either as an off-grid stand-alone, on-grid interactive, or non-grid interactive system.

Section Sign. A sign or outline lighting system, shipped as subassemblies, that requires field-installed wiring between the subassemblies to complete the overall sign. The subassemblies are either physically joined to form a single sign unit or are installed as separate remote parts of an overall sign.

Sign Body. A portion of a sign that may provide protection from the weather but is not an electrical enclosure.

Skeleton Tubing. Neon tubing that is itself the sign or outline lighting and is not attached to an enclosure or sign body.

Fixed, mobile, or portable electric signs, section signs, outline lighting, photovoltaic (PV) powered signs, and retrofit kits, regardless of voltage, shall be listed, provided with installation instructions, and installed in conformance with that listing, unless otherwise approved by special permission.
Field-installed skeleton tubing shall not be required to be listed where installed in conformance with this Code.
Outline lighting shall not be required to be listed as a system when it consists of listed luminaires wired in accordance with Chapter 3.
Signs and outline lighting systems shall be listed; marked with the manufacturer's name, trademark, or other means of identification; and input voltage and current rating.
  1. The retrofitted sign shall be marked that the illumination system has been replaced.
  2. The marking shall include the kit providers and installer's name, logo, or unique identifier.
  3. Signs equipped with tubular light-emitting diode lamps powered by the existing sign sockets shall include a label alerting the service personnel that the sign has been modified. The label shall meet the requirements of 110.21(B). The label shall also include a warning not to install fluorescent lamps and shall also be visible during relamping.
Signs and outline lighting systems with lampholders for incandescent lamps shall be marked to indicate the maximum allowable lamp wattage per lampholder. The markings shall be permanently installed, in letters at least 6 mm (1/4 in.) high, and shall be located where visible during relamping.
The markings required in 600.4(A) and listing labels shall not be required to be visible after installation but shall be permanently applied in a location visible during servicing.
Marking labels shall be permanent, durable and, when in wet locations, shall be weatherproof.
All signs, outline lighting, skeleton tubing systems, and retrofit kits shall be marked to indicate that field wiring and installation instructions are required.

Exception: Portable, cord-connected signs are not required to be marked.

Each commercial building and each commercial occupancy accessible to pedestrians shall be provided with at least one outlet in an accessible location at each entrance to each tenant space for sign or outline lighting system use. The outlet(s) shall be supplied by a branch circuit rated at least 20 amperes that supplies no other load. Service hallways or corridors shall not be considered accessible to pedestrians.
Branch circuits that supply signs shall be rated in accordance with 600.5(B)(1) or (B)(2) and shall be considered to be continuous loads for the purposes of calculations.
Branch circuits that supply neon tubing installations shall not be rated in excess of 30 amperes.
Branch circuits that supply all other signs and outline lighting systems shall be rated not to exceed 20 amperes.
Wiring methods used to supply signs shall comply with 600.5(C)(1), (C)(2), and (C)(3).
The wiring method used to supply signs and outline lighting systems shall terminate within a sign, an outline lighting system enclosure, a suitable box, or a conduit body.
Signs and transformer enclosures shall be permitted to be used as pull or junction boxes for conductors supplying other adjacent signs, outline lighting systems, or floodlights that are part of a sign and shall be permitted to contain both branch and secondary circuit conductors.
Metal or nonmetallic poles used to support signs shall be permitted to enclose supply conductors, provided the poles and conductors are installed in accordance with 410.30(B).
Each sign and outline lighting system, feeder conductor(s), or branch circuit(s) supplying a sign, outline lighting system, or skeleton tubing shall be controlled by an externally operable switch or circuit breaker that opens all ungrounded conductors and controls no other load. The switch or circuit breaker shall open all ungrounded conductors simultaneously on multi-wire branch circuits in accordance with 210.4(B). Signs and outline lighting systems located within fountains shall have the disconnect located in accordance with 680.13.

Exception No. 1: A disconnecting means shall not be required for an exit directional sign located within a building.

Exception No. 2: A disconnecting means shall not be required for cord-connected signs with an attachment plug.

Informational Note: The location of the disconnect is intended to allow service or maintenance personnel complete and local control of the disconnecting means.

The disconnecting means shall be permitted to be located in accordance with 600.6(A)(1), (A)(2), and (A)(3):
The disconnect shall be located at the point the feeder circuit or branch circuit(s) supplying a sign or outline lighting system enters a sign enclosure, a sign body, or a pole in accordance with 600.5(C)(3). The disconnect shall open all ungrounded conductors where it enters the enclosure of the sign or pole.

Exception No. 1: A disconnect shall not be required for branch circuit(s) or feeder conductor(s) passing through the sign where enclosed in a Chapter 3 listed raceway or metal-jacketed cable identified for the location.

Exception No. 2: A disconnect shall not be required at the point of entry to a sign enclosure or sign body for branch circuit(s) or feeder conductor(s) that supply an internal panelboard(s) in a sign enclosure or sign body. The conductors shall be enclosed in a Chapter 3 listed raceway or metal-jacketed cable identified for the location. A field-applied permanent warning label that is visible during servicing shall be applied to the raceway at or near the point of entry into the sign enclosure or sign body. The warning label shall comply with 110.21(B) and state the following: "Danger. This raceway contains energized conductors." The marking shall include the location of the disconnecting means for the energized conductor(s). The disconnecting means shall be capable of being locked in the open position in accordance with 110.25.

The disconnecting means shall be within sight of the sign or outline lighting system that it controls. Where the disconnecting means is out of the line of sight from any section that is able to be energized, the disconnecting means shall be lockable in accordance with 110.25. A permanent field-applied marking identifying the location of the disconnecting means shall be applied to the sign in a location visible during servicing. The warning label shall comply with 110.21(B).
The following shall apply for signs or outline lighting systems operated by electronic or electromechanical controllers located external to the sign or outline lighting system:
  1. The disconnecting means shall be located within sight of the controller or in the same enclosure with the controller.
  2. The disconnecting means shall disconnect the sign or outline lighting system and the controller from all ungrounded supply conductors.
  3. The disconnecting means shall be designed such that no pole can be operated independently and shall be lockable in accordance with 110.25.

Exception: Where the disconnecting means is not located within sight of the controller, a permanent field-applied marking identifying the location of the disconnecting means shall be applied to the controller in a location visible during servicing. The warning label shall comply with 110.21(B).

Switches, flashers, and similar devices controlling transformers and electronic power supplies shall be rated for controlling inductive loads or have a current rating not less than twice the current rating of the transformer or the electronic power supply.
Metal equipment of signs, outline lighting, and skeleton tubing systems shall be grounded by connection to the equipment grounding conductor of the supply branch circuit(s) or feeder using the types of equipment grounding conductors specified in 250.118.

Exception: Portable cord-connected signs shall not be required to be connected to the equipment grounding conductor where protected by a system of double insulation or its equivalent. Double insulated equipment shall be distinctively marked.

The equipment grounding conductor size shall be in accordance with 250.122 based on the rating of the overcurrent device protecting the branch circuit or feeder conductors supplying the sign or equipment.
Equipment grounding conductor connections shall be made in accordance with 250.130 and in a method specified in 250.8.
Auxiliary grounding electrode(s) shall be permitted for electric signs and outline lighting systems covered by this article and shall meet the requirements of 250.54.
Metal parts of a building shall not be permitted as a secondary return conductor or an equipment grounding conductor.
Metal parts and equipment of signs and outline lighting systems shall be bonded together and to the associated transformer or power-supply equipment grounding conductor of the branch circuit or feeder supplying the sign or outline lighting system and shall meet the requirements of 250.90.

Exception: Remote metal parts of a section sign or outline lighting system only supplied by a remote Class 2 power supply shall not be required to be bonded to an equipment grounding conductor.

Bonding connections shall be made in accordance with 250.8.
Metal parts of a building shall not be permitted to be used as a means for bonding metal parts and equipment of signs or outline lighting systems together or to the transformer or power-supply equipment grounding conductor of the supply circuit.
Listed flexible metal conduit or listed liquidtight flexible metal conduit that encloses the secondary circuit conductor from a transformer or power supply for use with neon tubing shall be permitted as a bonding means if the total accumulative length of the conduit in the secondary circuit does not exceed 30 m (100 ft).
Small metal parts not exceeding 50 mm (2 in.) in any dimension, not likely to be energized, and spaced at least 19 mm (3/4 in.) from neon tubing shall not require bonding.
Where listed nonmetallic conduit is used to enclose the secondary circuit conductor from a transformer or power supply and a bonding conductor is required, the bonding conductor shall be installed separate and remote from the nonmetallic conduit and be spaced at least 38 mm (11/2 in.) from the conduit when the circuit is operated at 100 Hz or less or 45 mm (13/4 in.) when the circuit is operated at over 100 Hz.
Bonding conductors shall comply with (1) and (2).
  1. Bonding conductors shall be copper and not smaller than 14 AWG.
  2. Bonding conductors installed externally of a sign or raceway shall be protected from physical damage.
Signs or outline lighting installed inside a fountain shall have all metal parts bonded to the equipment grounding conductor of the branch circuit for the fountain recirculating system. The bonding connection shall be as near as practicable to the fountain and shall be permitted to be made to metal piping systems that are bonded in accordance with 680.53.

Informational Note: Refer to 600.32(J) for restrictions on length of high-voltage secondary conductors.

Live parts, other than lamps, and neon tubing shall be enclosed. Transformers and power supplies provided with an integral enclosure, including a primary and secondary circuit splice enclosure, shall not require an additional enclosure.
Enclosures shall have ample structural strength and rigidity.
Sign and outline lighting system enclosures shall be constructed of metal or shall be listed.
Sheet copper or aluminum shall be at least 0.51 mm (0.020 in.) thick. Sheet steel shall be at least 0.41 mm (0.016 in.) thick.
Metal parts of equipment shall be protected from corrosion.
Sign or outline lighting system equipment shall be at least 4.3 m (14 ft) above areas accessible to vehicles unless protected from physical damage.
Neon tubing, other than listed, dry-location, portable signs, readily accessible to pedestrians shall be protected from physical damage.

Informational Note: See 600.41(D) for additional requirements.

Signs and outline lighting systems shall be installed so that adjacent combustible materials are not subjected to temperatures in excess of 90°C (194°F).

The spacing between wood or other combustible materials and an incandescent or HID lamp or lampholder shall not be less than 50 mm (2 in.).

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:
  1. Drain holes shall not be larger than 13 mm (1/2 in.) or smaller than 6 mm (1/4 in.).
  2. Every low point or isolated section of the equipment shall have at least one drain hole.
  3. Drain holes shall be positioned such that there will be no external obstructions.
Portable or mobile signs shall be adequately supported and readily movable without the use of tools.
An attachment plug shall be provided for each portable or mobile sign.
Portable or mobile signs in wet or damp locations shall comply with 600.10(C)(1) and (C)(2).
All cords shall be junior hard-service or hard-service types as designated in Table 400.4 and have an equipment grounding conductor.
The manufacturer of portable or mobile signs shall provide listed ground-fault circuit-interrupter protection for personnel. The ground-fault circuit interrupter shall be an integral part of the attachment plug or shall be located in the power-supply cord within 300 mm (12 in.) of the attachment plug.
Portable or mobile signs in dry locations shall meet the following:
  1. Cords shall be SP-2, SPE-2, SPT-2, or heavier, as designated in Table 400.4.
  2. The cord shall not exceed 4.5 m (15 ft) in length.
Field-installed secondary circuit wiring for electric signs, retrofit kits, outline lighting systems, skeleton tubing, and photovoltaic (PV) powered sign systems shall be in accordance with their installation instructions and 600.12(A), (B), or (C).
Neon and secondary circuit wiring of 1000 volts or less shall comply with 600.31.
Neon secondary circuit wiring of over 1000 volts shall comply with 600.32.
Where the installation complies with 600.33 and the power source provides a Class 2 output that complies with 600.24, either of the following wiring methods shall be permitted as determined by the installation instructions and conditions.
  1. Wiring methods identified in Chapter 3
  2. Class 2 cables complying with Table 600.33(A)(1) and Table 600.33(A)(2)
Ballasts, transformers, electronic power supplies, and Class 2 power sources shall be of the self-contained type or be enclosed by placement in a listed sign body or listed separate enclosure.
Ballasts, transformers, electronic power supplies, and Class 2 power sources shall be located where accessible and shall be securely fastened in place.
Ballasts, transformers, electronic power supplies, and Class 2 power sources shall be installed as near to the lamps or neon tubing as practicable to keep the secondary conductors as short as possible.
Ballasts, transformers, electronic power supplies, and Class 2 power sources used in wet locations shall be of the weatherproof type or be of the outdoor type and protected from the weather by placement in a sign body or separate enclosure.
A working space at least 900 mm (3 ft) high × 900 mm (3 ft) wide × 900 mm (3 ft) deep shall be provided at each ballast, transformer, electronic power supply, and Class 2 power source or at its enclosure where not installed in a sign.
Ballasts, transformers, electronic power supplies, and Class 2 power sources shall be permitted to be located in attics and soffits, provided there is an access door at least 900 mm × 562.5 mm (36 in. × 221/2 in.) and a passageway of at least 900 mm (3 ft) high × 600 mm (2 ft) wide with a suitable permanent walkway at least 300 mm (12 in.) wide extending from the point of entry to each component. At least one lighting outlet containing a switch or controlled by a wall switch shall be installed in such spaces. At least one point of control shall be at the usual point of entry to these spaces. The lighting outlet shall be provided at or near the equipment requiring servicing.
Ballasts, transformers, electronic power supplies, and Class 2 power sources shall be permitted to be located above suspended ceilings, provided that their enclosures are securely fastened in place and not dependent on the suspended-ceiling grid for support. Ballasts, transformers, and electronic power supplies installed in suspended ceilings shall not be connected to the branch circuit by flexible cord.
Ballasts shall be identified for the use and shall be listed.
Transformers and electronic power supplies shall be identified for the use and shall be listed.
Transformers and electronic power supplies other than the following shall have secondary-circuit ground-fault protection:
  1. Transformers with isolated ungrounded secondaries and with a maximum open circuit voltage of 7500 volts or less
  2. Transformers with integral porcelain or glass secondary housing for the neon tubing and requiring no field wiring of the secondary circuit
Secondary-circuit voltage shall not exceed 15,000 volts, nominal, under any load condition. The voltage to ground of any output terminals of the secondary circuit shall not exceed 7500 volts, under any load condition.
Transformers and electronic power supplies shall have a secondary-circuit current rating of not more than 300 mA.
Secondary circuit outputs shall not be connected in parallel or in series.
Transformers and electronic power supplies that are equipped with secondary-circuit ground-fault protection shall be so marked.
Class 2 transformers, power supplies, and power sources shall comply with the requirements of Class 2 circuits and 600.24(A), (B), (C), and (D).
Class 2 power supplies and power sources shall be listed for use with electric signs and outline lighting systems or shall be a component in a listed electric sign.
Metal parts of Class 2 power supplies and power sources shall be grounded by connecting to the equipment grounding conductor.
Conductors and equipment on the supply side of the power source shall be installed in accordance with the appropriate requirements of Chapter 3.
Secondary wiring on the load side of a Class 2 power source shall comply with 600.12(C) and 600.33.

Part II Field-Installed Skeleton Tubing, Outline Lighting, and Secondary Wiring

Part II of this article shall apply to all of the following:
  1. Field-installed skeleton tubing
  2. Field-installed secondary circuits
  3. Outline lighting

These requirements shall be in addition to the requirements of Part I.

Conductors shall be installed using any wiring method included in Chapter 3 suitable for the conditions.
Conductors shall be listed, insulated, and not smaller than 18 AWG.
The number of conductors in a raceway shall be in accordance with Table 1 of Chapter 9.
Conductors shall be installed so they are not subject to physical damage.
Bushings shall be used to protect wires passing through an opening in metal.
Conductors shall be installed in rigid metal conduit, intermediate metal conduit, liquidtight flexible nonmetallic conduit, flexible metal conduit, liquidtight flexible metal conduit, electrical metallic tubing, metal enclosures; on insulators in metal raceways; or in other equipment listed for use with neon secondary circuits over 1000 volts.
Conduit or tubing shall contain only one conductor.
Conduit or tubing shall be a minimum of metric designator 16 (trade size 1/2).
Other than at the location of connection to a metal enclosure or sign body, nonmetallic conduit or flexible nonmetallic conduit shall be spaced no less than 38 mm (11/2 in.) from grounded or bonded parts when the conduit contains a conductor operating at 100 Hz or less, and shall be spaced no less than 45 mm (13/4 in.) from grounded or bonded parts when the conduit contains a conductor operating at more than 100 Hz.
Metal parts of a building shall not be permitted as a secondary return conductor or an equipment grounding conductor.
Conductors shall be insulated, listed as gas tube sign and ignition cable type GTO, rated for 5, 10, or 15 kV, not smaller than 18 AWG, and have a minimum temperature rating of 105°C (221°F).
Conductors shall be so installed that they are not subject to physical damage.
Sharp bends in insulated conductors shall be avoided.
Secondary conductors shall be separated from each other and from all objects other than insulators or neon tubing by a spacing of not less than 38 mm (11/2 in.). GTO cable installed in metal conduit or tubing shall not require spacing between the cable insulation and the conduit or tubing.
Insulators and bushings for conductors shall be listed for use with neon secondary circuits over 1000 volts.
The insulation on all conductors shall extend not less than 65 mm (21/2 in.) beyond the metal conduit or tubing.
Conductors shall be permitted to run between the ends of neon tubing or to the secondary circuit midpoint return of listed transformers or listed electronic power supplies and provided with terminals or leads at the midpoint.
Equipment having an open circuit voltage exceeding 1000 volts shall not be installed in or on dwelling occupancies.
The length of secondary circuit conductors from a high-voltage terminal or lead of a transformer or electronic power supply to the first neon tube electrode shall not exceed the following:
  1. 6 m (20 ft) where installed in metal conduit or tubing
  2. 15 m (50 ft) where installed in nonmetallic conduit
All other sections of secondary circuit conductor in a neon tube circuit shall be as short as practicable.
Splices in high-voltage secondary circuit conductors shall be made in listed enclosures rated over 1000 volts. Splice enclosures shall be accessible after installation and listed for the location where they are installed.
The wiring methods and materials used shall be in accordance with the sign manufacturer's installation instructions using any applicable wiring methods from Chapter 3, Wiring Methods, and the requirements for Class 2 circuits contained in 600.12(C), 600.24, and 600.33(A), (B), (C), and (D).
Class 2 cable listed for the application that complies with Table 600.33(A)(1) or Table 600.33(A)(2) for substitutions shall be installed on the load side of the Class 2 power source. The conductors shall have an ampacity not less than the load to be supplied and shall not be sized smaller than 18 AWG.

Table 600.33(A)(1)
Applications of Power Limited Cable in Signs and Outline Lighting

Location CL2 CL3 CL2R CL3R CL2P CL3P PLTC
Non-concealed spaces inside buildings Y Y Y Y Y Y Y
Concealed spaces inside buildings that are not used as plenums or risers Y Y Y Y Y Y Y
Environmental air spaces plenums- or risers N N N N Y Y N
Wet locations N N N N N N Y
Y = Permitted. N = Not Permitted.


Table 600.33(A)(2)
Class 2 Cable Substitutions

Cable Type Permitted Substitutions
CL3P CMP
CL2P CMP, CL3P
CL3R CMP, CL3P, CMR
CL2R CMP, CL3P, CL2P, CMR, CL3R
CL3 CMP, CL3P, CMR, CL3R, CMG, CM, PLTC
CL2 CMP, CL3P, CL2P, CMR, CL3R, CL2R, CMG, CM, PLTC, CL3
CL3X CMP, CL3P, CMR, CL3R, CMG, CM, PLTC, CL3, CMX
CL2X CMP, CL3P, CL2P, CMR, CL3R, CL2R, CMG, CM, PLTC, CL3, CL2, CMX, CL3X
CL2 or CL3, PLTC, or any listed applicable cable for general use shall be installed within and on buildings or structures.
In other locations, any listed applicable cable permitted in 600.33(A)(1), (A)(2), (A)(3), and (A)(4) and Table 600.33(A)(1) and (A)(2) shall be permitted to be used as follows:
  1. CL2P or CL3P — Ducts, plenums, or other spaces used for environmental air
  2. CL2R or CL3R — Vertical shafts and risers
  3. Substitutions from Table 600.33(A)(2)
Class 2 cable used in a wet location shall be listed and marked suitable for use in a wet location.
Class 2 cable exposed to sunlight shall be listed and marked sunlight resistant suitable for outdoor use.
Secondary wiring shall be installed in accordance with (B)(1) and (B)(2).
  1. Wiring shall be installed and supported in a neat and workmanlike manner. Cables and conductors installed exposed on the surface of ceilings and sidewalls shall be supported by the building structure in such a manner that the cable is not damaged by normal building use. The cable shall be supported and secured at intervals not exceeding 1.8 m (6 ft). Such cables shall be supported by straps, staples, hangers, cable ties, or similar fittings designed and installed so as not to damage the cable. The installation shall also comply with 300.4(D).
  2. Connections in cable and conductors shall be made with listed insulating devices and be accessible after installation. Where made in a wall, connections shall be enclosed in a listed box.
Where subject to physical damage, the conductors shall be protected and installed in accordance with 300.4.
Grounding and bonding shall be in accordance with 600.7.
All field wiring of components and subassemblies for an off-grid stand-alone, on-grid interactive, or non-grid interactive PV installation shall be installed in accordance with Article 690, as applicable, 600.34, and the PV powered sign installation instructions.
Inverters, motor generators, PV modules, PV panels, ac PV modules, dc combiners, dc-ac converters, and charge controllers intended for use in PV powered sign systems shall be listed for PV application.
Wiring from a photovoltaic panel or wiring external to the PV sign body shall be:
  1. Listed, labeled, and suitable for photovoltaic applications
  2. Routed to closely follow the sign body or enclosure
  3. As short as possible and secured at intervals not exceeding 0.91 m (3 ft)
  4. Protected where subject to physical damage
Flexible cords and cables shall comply with Article 400 and be identified as extra hard usage, rated for outdoor use, and water and sunlight resistant.
Grounding a PV powered sign shall comply with Article 690, Part V and 600.7.
The disconnecting means for a PV powered sign shall comply with Article 690, Part III and 600.6.
Battery compartments shall require a tool to open.
The length and design of the tubing shall not cause a continuous overcurrent beyond the design loading of the transformer or electronic power supply.
Tubing shall be supported by listed tube supports. The neon tubing shall be supported within 150 mm (6 in.) from the electrode connection.
A spacing of not less than 6 mm (1/4 in.) shall be maintained between the tubing and the nearest surface, other than its support.
Field-installed skeleton tubing shall not be subject to physical damage. Where the tubing is readily accessible to other than qualified persons, field-installed skeleton tubing shall be provided with suitable guards or protected by other approved means.
Where the high-voltage secondary circuit conductors emerge from the wiring methods specified in 600.32(A), they shall be enclosed in a listed assembly.
Terminals of the electrode shall not be accessible to unqualified persons.
Connections shall be made by use of a connection device, twisting of the wires together, or use of an electrode receptacle. Connections shall be electrically and mechanically secure and shall be in an enclosure listed for the purpose.
Neon secondary conductor(s) shall be supported not more than 150 mm (6 in.) from the electrode connection to the tubing.
Electrode receptacles shall be listed.
Where electrodes penetrate an enclosure, bushings listed for the purpose shall be used unless receptacles are provided.
A listed cap shall be used to close the opening between neon tubing and a receptacle where the receptacle penetrates a building. Where a bushing or neon tubing penetrates a building, the opening between neon tubing and the bushing shall be sealed.
Electrode enclosures shall be listed.
Electrode enclosures that are listed, labeled, and identified for use in dry, damp, or wet locations shall be permitted to be installed and used in such locations.
Electrode enclosures installed in damp and wet locations shall be specifically listed, labeled, and identified for use in such locations.

Informational Note: See 110.3(B) covering installation and use of electrical equipment.

The provisions of this article apply to field-installed wiring using off-site manufactured subassemblies for branch circuits, remote-control circuits, signaling circuits, and communications circuits in accessible areas.

Manufactured Wiring System. A system containing component parts that are assembled in the process of manufacture and cannot be inspected at the building site without damage or destruction to the assembly and used for the connection of luminaires, utilization equipment, continuous plug-in type busways, and other devices.

Manufactured wiring systems and associated components shall be listed.

Informational Note: ANSI/UL 183, Standard for Manufacturing Wiring Systems, is a safety standard for manufactured wiring systems.

Manufactured wiring systems shall be secured and supported in accordance with the applicable cable or conduit article for the cable or conduit type employed.
Manufactured wiring systems shall be permitted in accessible and dry locations and in ducts, plenums, and other air-handling spaces where listed for this application and installed in accordance with 300.22.

Exception No. 1: In concealed spaces, one end of tapped cable shall be permitted to extend into hollow walls for direct termination at switch and outlet points.

Exception No. 2: Manufactured wiring system assemblies installed outdoors shall be listed for use in outdoor locations.

Manufactured wiring system types shall not be permitted where limited by the applicable article in Chapter 3 for the wiring method used in its construction.
Cable shall be one of the following:
  1. Listed Type AC cable containing nominal 600-volt, 8 to 12 AWG insulated copper conductors with a bare or insulated copper equipment grounding conductor equivalent in size to the ungrounded conductor.
  2. Listed Type MC cable containing nominal 600-volt, 8 to 12 AWG insulated copper conductors with a bare or insulated copper equipment grounding conductor equivalent in size to the ungrounded conductor.
  3. Listed Type MC cable containing nominal 600-volt, 8 to 12 AWG insulated copper conductors with a grounding conductor and armor assembly listed and identified for grounding in accordance with 250.118(10). The combined metallic sheath and grounding conductor shall have a current-carrying capacity equivalent to that of the ungrounded copper conductor.

Other cables as listed in 725.154, 800.113, 820.113, and 830.179 shall be permitted in manufactured wiring systems for wiring of equipment within the scope of their respective articles.

Conduit shall be listed flexible metal conduit or listed liquidtight flexible conduit containing nominal 600-volt, 8 to 12 AWG insulated copper conductors with a bare or insulated copper equipment grounding conductor equivalent in size to the ungrounded conductor.

Exception No. 1 to (1) and (2): A luminaire tap, no longer than 1.8 m (6 ft) and intended for connection to a single luminaire, shall be permitted to contain conductors smaller than 12 AWG but not smaller than 18 AWG.

Exception No. 2 to (1) and (2): Listed manufactured wiring assemblies containing conductors smaller than 12 AWG shall be permitted for remote-control, signaling, or communication circuits.

Exception No. 3 to (2): Listed manufactured wiring systems containing unlisted flexible metal conduit of noncircular cross section or trade sizes smaller than permitted by 348.20(A), or both, shall be permitted where the wiring systems are supplied with fittings and conductors at the time of manufacture.

Flexible cord suitable for hard usage, with minimum 12 AWG conductors, shall be permitted as part of a listed factory-made assembly not exceeding 1.8 m (6 ft) in length when making a transition between components of a manufactured wiring system and utilization equipment not permanently secured to the building structure. The cord shall be visible for the entire length, shall not be subject to physical damage, and shall be provided with identified strain relief.

Exception: Listed electric-discharge luminaires that comply with 410.62(C) shall be permitted with conductors smaller than 12 AWG.

Busways shall be listed continuous plug-in type containing factory-mounted, bare or insulated conductors, which shall be copper or aluminum bars, rods, or tubes. The busway shall be provided with an equipment ground. The busway shall be rated nominal 600 volts, 20, 30, or 40 amperes. Busways shall be installed in accordance with 368.12, 368.17(D), and 368.30.
Prewired, modular, surface-mounted raceways shall be listed for the use, rated nominal 600 volts, 20 amperes, and installed in accordance with 386.12, 386.30, 386.60, and 386.100.
Each section shall be marked to identify the type of cable, flexible cord, or conduit.
Receptacles and connectors shall be of the locking type, uniquely polarized and identified for the purpose, and shall be part of a listed assembly for the appropriate system. All connector openings shall be designed to prevent inadvertent contact with live parts or capped to effectively close the connector openings.
Other component parts shall be listed for the appropriate system.
This article covers electrical equipment, lighting accessories, and wiring systems used to connect, contained within, or installed on office furnishings.

Office Furnishing. Cubicle panels, partitions, study carrels, workstations, desks, shelving systems, and storage units that may be mechanically and electrically interconnected to form an office furnishing system.

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.

These assemblies shall be installed and used only as provided for by this article.
Where used in hazardous (classified) locations, these assemblies shall comply with Articles 500 through 517 in addition to this article.
All conductors and connections shall be contained within wiring channels of metal or other material identified as suitable for the conditions of use. Wiring channels shall be free of projections or other conditions that might damage conductor insulation.
The electrical connection between office furnishings shall be a flexible assembly identified for use with office furnishings or shall be permitted to be installed using flexible cord, provided that all the following conditions are met:
  1. The cord is extra-hard usage type with 12 AWG or larger conductors, with an insulated equipment grounding conductor.
  2. The office furnishings are mechanically contiguous.
  3. The cord is not longer than necessary for maximum positioning of the office furnishing but is in no case to exceed 600 mm (2 ft).
  4. The cord is terminated at an attachment plug-and-cord connector with strain relief.
Lighting equipment shall be listed, labeled, and identified for use with office furnishings and shall comply with 605.6(A), (B), and (C).
A means for secure attachment or support shall be provided.
Where cord and plug connection is provided, it shall comply with all of the following:
  1. The cord length shall be suitable for the intended application but shall not exceed 2.7 m (9 ft) in length.
  2. The cord shall not be smaller than 18 AWG.
  3. The cord shall contain an equipment grounding conductor, except as specified in 605.6(B)(4).
  4. Cords on the load side of a listed Class 2 power source shall not be required to contain an equipment grounding conductor.
  5. The cord shall be of the hard usage type, except as specified in 605.6(B)(6).
  6. A cord provided on a listed Class 2 power source shall be of the type provided with the listed luminaire assembly or of the type specified in 725.130 and 725.127.
  7. Connection by other means shall be identified as suitable for the conditions of use.
Receptacles shall not be permitted in lighting accessories.
Office furnishings that are fixed (secured to building surfaces) shall be permanently connected to the building electrical system by one of the wiring methods of Chapter 3.
Office furnishings of the freestanding type (not fixed) shall be permitted to be connected to the building electrical system by one of the wiring methods of Chapter 3.
Individual office furnishings of the freestanding type, or groups of individual office furnishings that are electrically connected, are mechanically contiguous, and do not exceed 9.0 m (30 ft) when assembled, shall be permitted to be connected to the building electrical system by a single flexible cord and plug, provided that all of the conditions of 605.9(A) through (D) are met.
The flexible power supply cord shall be extra-hard usage type with 12 AWG or larger conductors, with an insulated equipment grounding conductor, and shall not exceed 600 mm (2 ft) in length.
The receptacle(s) supplying power shall be on a separate circuit serving only the office furnishing and no other loads and shall be located not more than 300 mm (12 in.) from the office furnishing that is connected to it.
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.
An individual office furnishing or groups of interconnected office furnishings shall not contain multiwire circuits.

Informational Note: See 210.4 for circuits supplying office furnishings in 605.7 and 605.8.

Part I General

This article covers the installation of electrical equipment and wiring used in connection with cranes, monorail hoists, hoists, and all runways.

Informational Note: For further information, see ASME B30, Safety Standards for Cableways, Cranes, Derricks, Hoists, Hooks, Jacks, and Slings.

Festoon Cable. Single- and multiple-conductor cable intended for use and installation in accordance with Article 610 where flexibility is required.

All equipment that operates in a hazardous (classified) location shall conform to Article 500.
Equipment used in locations that are hazardous because of the presence of flammable gases or vapors shall conform to Article 501.
Equipment used in locations that are hazardous because of combustible dust shall conform to Article 502.
Equipment used in locations that are hazardous because of the presence of easily ignitible fibers or flyings shall conform to Article 503.
Where a crane, hoist, or monorail hoist operates over readily combustible material, the resistors shall be located as permitted in the following:
  1. A well ventilated cabinet composed of noncombustible material constructed so that it does not emit flames or molten metal
  2. A cage or cab constructed of noncombustible material that encloses the sides of the cage or cab from the floor to a point at least 150 mm (6 in.) above the top of the resistors

Part II Wiring

Conductors shall be enclosed in raceways or be Type AC cable with insulated grounding conductor, Type MC cable, or Type MI cable unless otherwise permitted or required in 610.11(A) through (E).
Contact conductors shall not be required to be enclosed in raceways.
Short lengths of exposed conductors at resistors, collectors, and other equipment shall not be required to be enclosed in raceways.
Where flexible connections are necessary, flexible stranded conductors shall be used. Conductors shall be in flexible metal conduit, liquidtight flexible metal conduit, liquidtight flexible nonmetallic conduit, multiconductor cable, or an approved nonmetallic flexible raceway.
Where multiconductor cable is used with a suspended pushbutton station, the station shall be supported in some satisfactory manner that protects the electrical conductors against strain.
Where flexibility is required for power or control to moving parts, listed festoon cable or a cord suitable for the purpose shall be permitted, provided the following apply:
  1. Suitable strain relief and protection from physical damage is provided.
  2. In Class I, Division 2 locations, the cord is approved for extra-hard usage.
Conductors leaving raceways or cables shall comply with either 610.12(A) or (B).
A box or terminal fitting that has a separately bushed hole for each conductor shall be used wherever a change is made from a raceway or cable to exposed wiring. A fitting used for this purpose shall not contain taps or splices and shall not be used at luminaire outlets.
A bushing shall be permitted to be used in lieu of a box at the end of a rigid metal conduit, intermediate metal conduit, or electrical metallic tubing where the raceway terminates at unenclosed controls or similar equipment, including contact conductors, collectors, resistors, brakes, power-circuit limit switches, and dc split-frame motors.
Conductors shall comply with Table 310.104(A) unless otherwise permitted in 610.13(A) through (D).
A conductor(s) exposed to external heat or connected to resistors shall have a flame-resistant outer covering or be covered with flame-resistant tape individually or as a group.
Contact conductors along runways, crane bridges, and monorails shall be permitted to be bare and shall be copper, aluminum, steel, or other alloys or combinations thereof in the form of hard-drawn wire, tees, angles, tee rails, or other stiff shapes.
Where flexibility is required, listed flexible cord or cable, or listed festoon cable, shall be permitted to be used and, where necessary, cable reels or take-up devices shall be used.
Conductors for Class 1, Class 2, and Class 3 remote-control, signaling, and power-limited circuits, installed in accordance with Article 725, shall be permitted.
The allowable ampacities of conductors shall be as shown in Table 610.14(A).

Informational Note: For the ampacities of conductors between controllers and resistors, see 430.23.

Table 610.14(A) Ampacities of Insulated Copper Conductors Used with Short-Time Rated Crane and Hoist Motors. Based on Ambient Temperature of 30°C (86°F).

Maximum Operating Temperature Up to Four Simultaneously Energized Conductors in Raceway or Cable1 Up to Three ac2 or Four dc1 Simultaneously Energized Conductors in Raceway or Cable Maximum Operating Temperature
75°C (167°F) 90°C (194°F) 125°C (257°F)
Size (AWG or kcmil) Types MTW, RHW, THW, THWN, XHHW, USE, ZW Types TA, TBS, SA, SIS, PFA, FEP, FEPB, RHH, THHN, XHHW, Z, ZW Types FEP, FEPB, PFA, PFAH, SA, TFE, Z, ZW Size (AWG or kcmil)
60 Min 30 Min 60 Min 30 Min 60 Min 30 Min
16 10 12 16
14 25 26 31 32 38 40 14
12 30 33 36 40 45 50 12
10 40 43 49 52 60 65 10
8 55 60 63 69 73 80 8
6 76 86 83 94 101 119 6
5 85 95 95 106 115 134 5
4 100 117 111 130 133 157 4
3 120 141 131 153 153 183 3
2 137 160 148 173 178 214 2
1 143 175 158 192 210 253 1
1/0 190 233 211 259 253 304 1/0
2/0 222 267 245 294 303 369 2/0
3/0 280 341 305 372 370 452 3/0
4/0 300 369 319 399 451 555 4/0
250 364 420 400 461 510 635 250
300 455 582 497 636 587 737 300
350 486 646 542 716 663 837 350
400 538 688 593 760 742 941 400
450 600 765 660 836 818 1042 450
500 660 847 726 914 896 1143 500
AMPACITY CORRECTION FACTORS
Ambient Temperature (°C) For ambient temperatures other than 30°C (86°F), multiply the ampacities shown above by the appropriate factor shown below. Ambient Temperature (°F)
21—25 1.05 1.05 1.04 1.04 1.02 1.02 70—77
26—30 1.00 1.00 1.00 1.00 1.00 1.00 79—86
31—35 0.94 0.94 0.96 0.96 0.97 0.97 88—95
36—40 0.88 0.88 0.91 0.91 0.95 0.95 97—104
41—45 0.82 0.82 0.87 0.87 0.92 0.92 106—113
46—50 0.75 0.75 0.82 0.82 0.89 0.89 115—122
51—55 0.67 0.67 0.76 0.76 0.86 0.86 124—131
56—60 0.58 0.58 0.71 0.71 0.83 0.83 133—140
61—70 0.33 0.33 0.58 0.58 0.76 0.76 142—158
71—80 0.41 0.41 0.69 0.69 160—176
81—90 0.61 0.61 177—194
91—100 0.51 0.51 195—212
101—120 0.40 0.40 213—248
Note: Other insulations shown in Table 310.104(A) and approved for the temperature and location shall be permitted to be substituted for those shown in Table 610.14(A). The allowable ampacities of conductors used with 15-minute motors shall be the 30-minute ratings increased by 12 percent.
1 For 5 to 8 simultaneously energized power conductors in raceway or cable, the ampacity of each power conductor shall be reduced to a value of 80 percent of that shown in this table.
2 For 4 to 6 simultaneously energized 125°C (257°F) ac power conductors in raceway or cable, the ampacity of each power conductor shall be reduced to a value of 80 percent of that shown in this table.
Where the secondary resistor is separate from the controller, the minimum size of the conductors between controller and resistor shall be calculated by multiplying the motor secondary current by the appropriate factor from Table 610.14(B) and selecting a wire from Table 610.14(A).

Table 610.14(B)
Secondary Conductor Rating Factors

Time in Seconds Ampacity of Wire in Percent of Full-Load Secondary Current
On Off
5 75 35
10 70 45
15 75 55
15 45 65
15 30 75
15 15 85
Continuous Duty 110
Conductors external to motors and controls shall be not smaller than 16 AWG unless otherwise permitted in (1) or (2):
  1. 18 AWG wire in multiconductor cord shall be permitted for control circuits not exceeding 7 amperes.
  2. Wires not smaller than 20 AWG shall be permitted for electronic circuits.
Contact wires shall have an ampacity not less than that required by Table 610.14(A) for 75°C (167°F) wire, and in no case shall they be smaller than as shown in Table 610.14(D).

Table 610.14(D)
Minimum Contact Conductor Size Based on Distance Between Supports

Minimum Size of Wire (AWG) Maximum Distance Between End Strain Insulators or Clamp-Type Intermediate Supports
6 9.0 m (30 ft) or less
4 18 m (60 ft) or less
2 Over 18 m (60 ft)

Table 610.14(E)
Demand Factors

Number of Cranes or Hoists Demand Factor
2 0.95
3 0.91
4 0.87
5 0.84
6 0.81
7 0.78
For one motor, 100 percent of motor nameplate full-load ampere rating shall be used.
For multiple motors on a single crane or hoist, the minimum ampacity of the power supply conductors shall be the nameplate full-load ampere rating of the largest motor or group of motors for any single crane motion, plus 50 percent of the nameplate full-load ampere rating of the next largest motor or group of motors, using that column of Table 610.14(A) that applies to the longest time-rated motor.
For multiple cranes, hoists, or both, supplied by a common conductor system, calculate the motor minimum ampacity shall be calculated for each crane as defined in 610.14(E), added them together, and the sum multiplied by the appropriate demand factor from Table 610.14(E).
Additional loads, such as heating, lighting, and air conditioning, shall be provided for by application of the appropriate sections of this Code.
Each crane, monorail, or hoist shall be provided with a visible nameplate marked with the manufacturer's name, rating in volts, frequency, number of phases, and circuit amperes as calculated in 610.14(E) and (F).
Where a crane or hoist is operated by more than one motor, a common-return conductor of proper ampacity shall be permitted.

Part III Contact Conductors

Contact conductors shall comply with 610.21(A) through (H).
Runway contact conductors shall be guarded, and bridge contact conductors shall be located or guarded in such a manner that persons cannot inadvertently touch energized current-carrying parts.
Wires that are used as contact conductors shall be secured at the ends by means of approved strain insulators and shall be mounted on approved insulators so that the extreme limit of displacement of the wire does not bring the latter within less than 38 mm (11/2 in.) from the surface wired over.
Main contact conductors carried along runways shall be supported on insulating supports placed at intervals not exceeding 6.0 m (20 ft) unless otherwise permitted in 610.21(F).

Such conductors shall be separated at not less than 150 mm (6 in.), other than for monorail hoists where a spacing of not less than 75 mm (3 in.) shall be permitted. Where necessary, intervals between insulating supports shall be permitted to be increased up to 12 m (40 ft), the separation between conductors being increased proportionately.

Bridge wire contact conductors shall be kept at least 65 mm (21/2 in.) apart, and, where the span exceeds 25 m (80 ft), insulating saddles shall be placed at intervals not exceeding 15 m (50 ft).
Conductors along runways and crane bridges, that are of the rigid type specified in 610.13(B) and not contained within an approved enclosed assembly, shall be carried on insulating supports spaced at intervals of not more than 80 times the vertical dimension of the conductor, but in no case greater than 4.5 m (15 ft), and spaced apart sufficiently to give a clear electrical separation of conductors or adjacent collectors of not less than 25 mm (1 in.).
Monorail, tram rail, or crane runway tracks shall be permitted as a conductor of current for one phase of a 3-phase, ac system furnishing power to the carrier, crane, or trolley, provided all of the following conditions are met:
  1. The conductors supplying the other two phases of the power supply are insulated.
  2. The power for all phases is obtained from an insulating transformer.
  3. The voltage does not exceed 300 volts.
  4. The rail serving as a conductor shall be bonded to the equipment grounding conductor at the transformer and also shall be permitted to be grounded by the fittings used for the suspension or attachment of the rail to a building or structure.
All sections of contact conductors shall be mechanically joined to provide a continuous electrical connection.
Contact conductors shall not be used as feeders for any equipment other than the crane(s) or hoist(s) that they are primarily designed to serve.
Collectors shall be designed so as to reduce to a minimum sparking between them and the contact conductor; and, where operated in rooms used for the storage of easily ignitible combustible fibers and materials, they shall comply with 503.155.

Part IV Disconnecting Means

A disconnecting means that has a continuous ampere rating not less than that calculated in 610.14(E) and (F) shall be provided between the runway contact conductors and the power supply. The disconnecting means shall comply with 430.109. This disconnecting means shall be as follows:
  1. Readily accessible and operable from the ground or floor level
  2. Lockable open in accordance with 110.25
  3. Open all ungrounded conductors simultaneously
  4. Placed within view of the runway contact conductors

Exception: The runway conductor disconnecting means for electrolytic cell lines shall be permitted to be placed out of view of the runway contact conductors where either of the following conditions are met:

  1. Where a location in view of the contact conductors is impracticable or introduces additional or increased hazards to persons or property
  2. In industrial installations, with written safety procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment
A disconnecting means in compliance with 430.109 shall be provided in the leads from the runway contact conductors or other power supply on all cranes and monorail hoists. The disconnecting means shall be lockable open in accordance with 110.25.

Where a monorail hoist or hand-propelled crane bridge installation meets all of the following, the disconnecting means shall be permitted to be omitted:

  1. The unit is controlled from the ground or floor level.
  2. The unit is within view of the power supply disconnecting means.
  3. No fixed work platform has been provided for servicing the unit.

Means shall be provided at the operating station to open the power circuit to all motors of the crane or monorail hoist.

The continuous ampere rating of the switch or circuit breaker required by 610.32 shall not be less than 50 percent of the combined short-time ampere rating of the motors or less than 75 percent of the sum of the short-time ampere rating of the motors required for any single motion.

Part V Overcurrent Protection

The runway supply conductors and main contact conductors of a crane or monorail shall be protected by an overcurrent device(s) that shall not be greater than the largest rating or setting of any branch-circuit protective device plus the sum of the nameplate ratings of all the other loads with application of the demand factors from Table 610.14(E).
Where more than one feeder circuit is installed to supply runway conductors, each feeder circuit shall be sized and protected in compliance with 610.41(A).
Branch circuits shall be protected in accordance with 610.42(A). Branch-circuit taps, where made, shall comply with 610.42(B).
Crane, hoist, and monorail hoist motor branch circuits shall be protected by fuses or inverse-time circuit breakers that have a rating in accordance with Table 430.52. Where two or more motors operate a single motion, the sum of their nameplate current ratings shall be considered as that of a single motor.
Where two or more motors are connected to the same branch circuit, each tap conductor to an individual motor shall have an ampacity not less than one-third that of the branch circuit. Each motor shall be protected from overload according to 610.43.
Where taps to control circuits originate on the load side of a branch-circuit protective device, each tap and piece of equipment shall be protected in accordance with 430.72.
Each motor, motor controller, and branch-circuit conductor shall be protected from overload by one of the following means:
  1. A single motor shall be considered as protected where the branch-circuit overcurrent device meets the rating requirements of 610.42.
  2. Overload relay elements in each ungrounded circuit conductor, with all relay elements protected from short circuit by the branch-circuit protection.
  3. Thermal sensing devices, sensitive to motor temperature or to temperature and current, that are thermally in contact with the motor winding(s). Hoist functions shall be considered to be protected if the sensing device limits the hoist to lowering only during an overload condition. Traverse functions shall be considered to be protected if the sensing device limits the travel in both directions for the affected function during an overload condition of either motor.
If the motor is manually controlled, with spring return controls, the overload protective device shall not be required to protect the motor against stalled rotor conditions.
Where two or more motors drive a single trolley, truck, or bridge and are controlled as a unit and protected by a single set of overload devices with a rating equal to the sum of their rated full-load currents, a hoist or trolley shall be considered to be protected if the sensing device is connected in the hoist's upper limit switch circuit so as to prevent further hoisting during an overtemperature condition of either motor.
Hoists and monorail hoists and their trolleys that are not used as part of an overhead traveling crane shall not require individual motor overload protection, provided the largest motor does not exceed 71/2 hp and all motors are under manual control of the operator.

Part VI Control

Each motor shall be provided with an individual controller unless otherwise permitted in 610.51(A) or (B).
Where two or more motors drive a single hoist, carriage, truck, or bridge, they shall be permitted to be controlled by a single controller.
One controller shall be permitted to be switched between motors, under the following conditions:
  1. The controller has a horsepower rating that is not lower than the horsepower rating of the largest motor.
  2. Only one motor is operated at one time.
Conductors of control circuits shall be protected against overcurrent. Control circuits shall be considered as protected by overcurrent devices that are rated or set at not more than 300 percent of the ampacity of the control conductors, unless otherwise permitted in 610.53(A) or (B).
Taps to control transformers shall be considered as protected where the secondary circuit is protected by a device rated or set at not more than 200 percent of the rated secondary current of the transformer and not more than 200 percent of the ampacity of the control circuit conductors.
Where the opening of the control circuit would create a hazard, as for example, the control circuit of a hot metal crane, the control circuit conductors shall be considered as being properly protected by the branch-circuit overcurrent devices.
The dimension of the working space in the direction of access to live parts that are likely to require examination, adjustment, servicing, or maintenance while energized shall be a minimum of 750 mm (21/2 ft). Where controls are enclosed in cabinets, the door(s) shall either open at least 90 degrees or be removable.

Part VII Grounding

All exposed non-current-carrying metal parts of cranes, monorail hoists, hoists, and accessories, including pendant controls, shall be bonded either by mechanical connections or bonding jumpers, where applicable, so that the entire crane or hoist is a ground-fault current path as required or permitted by Article 250, Parts V and VII.

Moving parts, other than removable accessories, or attachments that have metal-to-metal bearing surfaces, shall be considered to be electrically bonded to each other through bearing surfaces for grounding purposes. The trolley frame and bridge frame shall not be considered as electrically grounded through the bridge and trolley wheels and its respective tracks. A separate bonding conductor shall be provided.

Part I General

This article covers the installation of electrical equipment and wiring used in connection with elevators, dumbwaiters, escalators, moving walks, platform lifts, and stairway chairlifts.

Informational Note No. 1: For further information, see ASMEA17.1-2013/CSA B44-13, Safety Code for Elevators and Escalators.

Informational Note No. 2: For further information, see CSA B44.1-11/ASME-A17.5-2014, Elevator and Escalator Electrical Equipment.

Informational Note No. 3: The term wheelchair lift has been changed to platform lift. For further information, see ASME A18.1-2014, Safety Standard for Platform Lifts and Stairway Chairlifts.

Informational Note No. 1: The motor controller, motion controller, and operation controller are located in a single enclosure or a combination of enclosures.

Informational Note No. 2: Informational Note Figure 620.2, No. 2 is for information only.

Control Room (for Elevator, Dumbwaiter). An enclosed control space outside the hoistway, intended for full bodily entry, that contains the elevator motor controller. The room could also contain electrical and/or mechanical equipment used directly in connection with the elevator or dumbwaiter but not the electric driving machine or the hydraulic machine.

Informational Note Figure 620.2, No. 2 Control System.

Control Space (for Elevator, Dumbwaiter). A space inside or outside the hoistway, intended to be accessed with or without full bodily entry, that contains the elevator motor controller. This space could also contain electrical and/or mechanical equipment used directly in connection with the elevator or dumbwaiter but not the electrical driving machine or the hydraulic machine.

Control System. The overall system governing the starting, stopping, direction of motion, acceleration, speed, and retardation of the moving member.

Controller, Motion. The electrical device(s) for that part of the control system that governs the acceleration, speed, retardation, and stopping of the moving member.

Controller, Motor. The operative units of the control system comprised of the starter device(s) and power conversion equipment used to drive an electric motor, or the pumping unit used to power hydraulic control equipment.

Controller, Operation. The electrical device(s) for that part of the control system that initiates the starting, stopping, and direction of motion in response to a signal from an operating device.

Machine Room (for Elevator, Dumbwaiter). An enclosed machinery space outside the hoistway, intended for full bodily entry, that contains the electrical driving machine or the hydraulic machine. The room could also contain electrical and/or mechanical equipment used directly in connection with the elevator or dumbwaiter.

Machinery Space (for Elevator, Dumbwaiter). A space inside or outside the hoistway, intended to be accessed with or without full bodily entry, that contains elevator or dumbwaiter mechanical equipment, and could also contain electrical equipment used directly in connection with the elevator or dumbwaiter. This space could also contain the electrical driving machine or the hydraulic machine.

Operating Device. The car switch, pushbuttons, key or toggle switch(s), or other devices used to activate the operation controller.

Remote Machine Room and Control Room (for Elevator, Dumbwaiter). A machine room or control room that is not attached to the outside perimeter or surface of the walls, ceiling, or floor of the hoistway.

Remote Machinery Space and Control Space (for Elevator, Dumbwaiter). A machinery space or control space that is not within the hoistway, machine room, or control room and that is not attached to the outside perimeter or surface of the walls, ceiling, or floor of the hoistway.

Signal Equipment. Includes audible and visual equipment such as chimes, gongs, lights, and displays that convey information to the user.

The supply voltage shall not exceed 300 volts between conductors unless otherwise permitted in 620.3(A) through (C).
Branch circuits to door operator controllers and door motors and branch circuits and feeders to motor controllers, driving machine motors, machine brakes, and motor-generator sets shall not have a circuit voltage in excess of 1000 volts. Internal voltages of power conversion equipment and functionally associated equipment, and the operating voltages of wiring interconnecting the equipment, shall be permitted to be higher, provided that all such equipment and wiring shall be listed for the higher voltages. Where the voltage exceeds 600 volts, warning labels or signs that read "DANGER — HIGH VOLTAGE" shall be attached to the equipment and shall be plainly visible. The danger sign(s) or label(s) shall comply with 110.21(B).
Lighting circuits shall comply with the requirements of Article 410.
Branch circuits for heating and air-conditioning equipment located on the elevator car shall not have a circuit voltage in excess of 1000 volts.
All live parts of electrical apparatus in the hoistways, at the landings, in or on the cars of elevators and dumbwaiters, in the wellways or the landings of escalators or moving walks, or in the runways and machinery spaces of platform lifts and stairway chairlifts shall be enclosed to protect against accidental contact.

Informational Note: See 110.27 for guarding of live parts (1000 volts, nominal, or less).

Working space shall be provided about controllers, disconnecting means, and other electrical equipment in accordance with 110.26(A).

Where conditions of maintenance and supervision ensure that only qualified persons examine, adjust, service, and maintain the equipment, the clearance requirements of 110.26(A) shall not be required where any of the conditions in 620.5(A) through (D) are met.

Electrical equipment in (A)(1) through (A)(4) is provided with flexible leads to all external connections so that it can be repositioned to meet the clear working space requirements of 110.26:
  1. Controllers and disconnecting means for dumbwaiters, escalators, moving walks, platform lifts, and stairway chairlifts installed in the same space with the driving machine
  2. Controllers and disconnecting means for elevators installed in the hoistway or on the car
  3. Controllers for door operators
  4. Other electrical equipment installed in the hoistway or on the car
Live parts of the electrical equipment are suitably guarded, isolated, or insulated to reduce the likelihood of inadvertent contact with live parts operating at voltages greater than 30 volts ac rms, 42 volts ac peak, or 60 volts dc, and the equipment can be examined, adjusted, serviced, or maintained while energized without removal of this protection.
Electrical equipment is not required to be examined, adjusted, serviced, or maintained while energized.
Uninsulated parts are at a voltage not greater than 30 volts rms, 42 volts peak, or 60 volts dc.

Part II Conductors

The insulation of conductors shall comply with 620.11(A) through (D).

Informational Note: One method of determining that the insulation of conductors is flame retardant is by testing the conductors or cables to the VW-1 (Vertical-Wire) Flame Test in ANSI/UL 1581-2011, Reference Standard for Electrical Wires, Cables, and Flexible Cords.

The conductors to the hoistway door interlocks from the hoistway riser shall be one of the following:
  1. Flame-retardant and suitable for a temperature of not less than 200°C (392°F). Conductors shall be Type SF or equivalent.
  2. Physically protected using an approved method, such that the conductor assembly is flame-retardant and suitable for a temperature of not less than 200°C (392°F).
Traveling cables used as flexible connections between the elevator or dumbwaiter car or counterweight and the raceway shall be of the types of elevator cable listed in Table 400.4 or other approved types.
All conductors in raceways shall have flame-retardant insulation.

Conductors shall be Type MTW, TF, TFF, TFN, TFFN, THHN, THW, THWN, TW, XHHW, hoistway cable, or any other conductor with insulation designated as flame retardant. Shielded conductors shall be permitted if such conductors are insulated for the maximum nominal circuit voltage applied to any conductor within the cable or raceway system.

All conductors shall have an insulation voltage rating equal to at least the maximum nominal circuit voltage applied to any conductor within the enclosure, cable, or raceway. Insulations and outer coverings that are marked for limited smoke and are so listed shall be permitted.
The minimum size of conductors, other than conductors that form an integral part of control equipment, shall be in accordance with 620.12(A) and (B).
For lighting circuits, 14 AWG copper, 20 AWG copper or larger conductors shall be permitted in parallel, provided the ampacity is equivalent to at least that of 14 AWG copper.
For other circuits, 20 AWG copper.
24 AWG copper. Smaller size listed conductors shall be permitted.
Conductors shall have an ampacity in accordance with 620.13(A) through (D). With generator field control, the conductor ampacity shall be based on the nameplate current rating of the driving motor of the motor-generator set that supplies power to the elevator motor.

Informational Note No. 1: The heating of conductors depends on root-mean-square current values, which, with generator field control, are reflected by the nameplate current rating of the motor-generator driving motor rather than by the rating of the elevator motor, which represents actual but short-time and intermittent full-load current values.

Informational Note No. 2: See Informational Note, Figure 620.13, No. 2.

Conductors supplying a single motor shall have an ampacity not less than the percentage of motor nameplate current determined from 430.22(A) and (E).

Informational Note: Some elevator motor currents, or those motor currents of similar function, exceed the motor nameplate value. Heating of the motor and conductors is dependent on the root-mean square (rms) current value and the length of operation time. Because this motor application is inherently intermittent duty, conductors are sized for duty cycle service as shown in Table 430.22(E).

Conductors supplying a single motor controller shall have an ampacity not less than the motor controller nameplate current rating, plus all other connected loads. Motor controller nameplate current ratings shall be permitted to be derived based on the rms value of the motor current using an intermittent duty cycle and other control system loads, if present.
Conductors supplying a single power transformer shall have an ampacity not less than the nameplate current rating of the power transformer plus all other connected loads.

Informational Note No. 1: The nameplate current rating of a power transformer supplying a motor controller reflects the nameplate current rating of the motor controller at line voltage (transformer primary).

Informational Note No. 2: See Informative Annex D, Example No. D10.

FIGURE 620.13 Informational Note Single-Line Diagram, No. 2.

Conductors supplying more than one motor, motor controller, or power transformer shall have an ampacity not less than the sum of the nameplate current ratings of the equipment plus all other connected loads. The ampere ratings of motors to be used in the summation shall be determined from Table 430.22(E), 430.24, and 430.24, Exception No. 1.

Informational Note: See Informative Annex D, Example Nos. D9 and D10.

Feeder conductors of less ampacity than required by 620.13 shall be permitted, subject to the requirements of Table 620.14.

Table 620.14
Feeder Demand Factors for Elevators

Number of Elevators on a Single Feeder Demand Factor*
1 1.00
2 0.95
3 0.90
4