12.1 Signs, Cranes, Elevators, Electric Vehicle Charging and Welders

Article 600 — Electric Signs and Outline Lighting

600.5(A) Required Branch Circuit. 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.

600.5(B)(1) Rating. Branch circuits that supply signs shall be rated not to exceed 20 amperes for circuits supplying ballasts, transformers, LED drivers, or electronic power supplies; and not to exceed 30 amperes for circuits supplying incandescent or LED lamps and lampholders.

220.14(F) requires the load for the required sign or outline lighting outlet to be computed at a minimum of 1200 volt-amperes for each required branch circuit.

600.5(C)(3) Ground-Fault Circuit-Interrupter Protection. All 15- and 20-ampere, 125-volt through 250-volt receptacles installed in accordance with 600.5(A) shall have GFCI protection for personnel integral to the receptacle or the branch circuit.

600.6 Disconnects. Each sign and outline lighting system, feeder circuit, or branch circuit supplying a sign, outline lighting system, or skeleton tubing shall be controlled by an externally operable switch or circuit breaker that will open all ungrounded conductors and controls no other load. The disconnect shall be capable of being locked in the open position in accordance with 110.25.

600.6(A)(1) At Point of Entry to a Sign Enclosure. The disconnect shall be within sight of the sign or outline lighting system it controls. Where the disconnect is out of the line of sight from any section that is able to be energized, the disconnecting means shall be capable of being locked in the open position.

600.7 Grounding and Bonding. Signs and metal equipment of outline lighting systems shall be grounded and bonded as specified in the section. 600.7(B)(1) requires bonding of metal parts and equipment of signs and outline lighting systems. 600.7(B)(5) requires the bonding conductor to be copper, not smaller than 14 AWG.

600.10 Portable or Mobile Signs. Portable or mobile signs shall meet the requirements of the section, including GFCI protection where in a wet or damp location, with the GFCI to be an integral part of the attachment plug or located in the power-supply cord within 300 mm (12 in.) of the attachment plug.

Article 610 — Cranes and Hoists

610.11 Wiring Method. Conductors shall be enclosed in raceways or be Type AC cable with insulated equipment grounding conductor, Type MC cable, or Type MI cable, unless otherwise permitted or required.

610.14(A) Ampacity of Conductors. The allowable ampacities of conductors shall be as shown in Table 610.14(A), which gives values for conductors used with short-time-rated motors on 30-, 60-, and continuous-duty cycles.

610.14(E) Multiple Motors. Conductors supplying more than one motor shall have an ampacity at least equal to the sum of the nameplate current ratings of all motors on the panel, plus a percentage of the nameplate current rating of the largest motor.

610.32 Disconnecting Means for Runway Conductors. A readily accessible disconnecting means shall be provided between the runway contact conductors and the power supply. Such disconnecting means shall consist of a motor-circuit switch, circuit breaker, or molded case switch, shall be lockable open in accordance with 110.25, and shall open all ungrounded conductors simultaneously.

610.33 Rating of Disconnecting Means. 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.

Article 620 — Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts

620.21 Wiring Methods. Conductors and optical fibers located in hoistways, in escalator and moving walk wellways, in platform lifts, stairway chairlift runways, machinery spaces, control spaces, in or on cars, in machine rooms and control rooms, not including the traveling cables connecting the car or counterweight and hoistway wiring, shall be installed in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or wireways, or shall be Type MC, MI, or AC cable, unless otherwise permitted in 620.21(A) through (C).

620.22(A) Car Light Source. A separate branch circuit shall supply the car lights, receptacle(s), auxiliary lighting power source, and ventilation on each elevator car. The overcurrent device protecting each branch circuit shall be located in the elevator machine room or control room.

620.23 requires a separate branch circuit for the machine room or control room lighting and receptacles, and 620.24 for the hoistway pit lighting and receptacles. The lighting switch shall be readily accessible from the point of entry, and the required lighting shall not be connected to the load side of a ground-fault circuit interrupter.

620.51 Disconnecting Means. A single means for disconnecting all ungrounded main power supply conductors for each unit shall be provided and be designed so that no pole can be operated independently. Where multiple driving machines are connected to a single elevator, escalator, moving walk, or pumping unit, there shall be one disconnecting means to disconnect the motor(s) and control valve operating magnets.

• (A) Type. The disconnecting means shall be an enclosed externally operable fused motor-circuit switch or circuit breaker, lockable open in accordance with 110.25.
• (C) Location. The disconnecting means shall be located where it is readily accessible to qualified persons, in the specified locations for each type of equipment.
• (D) Identification and Signs. Where there is more than one driving machine in a machine room, the disconnecting means shall be numbered to correspond to the identifying number of the driving machine that they control.

620.62 Selective Coordination. Where more than one driving machine disconnecting means is supplied by a single feeder, the overcurrent protective devices in each disconnecting means shall be selectively coordinated with any other supply-side overcurrent protective devices. Selective coordination shall be selected by a licensed professional engineer or other qualified person engaged primarily in the design, installation, or maintenance of electrical systems, and the selection shall be documented and made available to those authorized to design, install, inspect, maintain, and operate the system.

Article 625 — Electric Vehicle Power Transfer System

625.40 Electric Vehicle Branch Circuit. Each outlet installed for the purpose of charging electric vehicles shall be supplied by an individual branch circuit. Each circuit shall have no other outlets.

625.41 Overcurrent Protection. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply equipment or wireless power transfer equipment shall be sized for continuous duty and shall have a rating of not less than 125 percent of the maximum load of the equipment. Where noncontinuous loads are supplied from the same feeder or branch circuit, the overcurrent device shall have a rating of not less than the sum of the noncontinuous loads plus 125 percent of the continuous loads.

625.42 Rating. Electric vehicle supply equipment and wireless power transfer equipment shall have sufficient rating to supply the load served. Electric vehicle charging loads shall be considered continuous loads. Where an automatic load management system is used, the maximum equipment load on a service or feeder shall be the maximum load permitted by the automatic load management system.

625.43 Disconnecting Means. For equipment rated more than 60 amperes or more than 150 volts to ground, the disconnecting means shall be provided and installed in a readily accessible location. The disconnecting means shall be capable of being locked in the open position.

625.44 Equipment Connection. (A) Portable equipment shall be permitted to be cord-and-plug connected to a receptacle outlet. (B) Fastened-in-place equipment rated 250 volts or less shall be permitted to be cord-and-plug connected where the cord does not exceed 1.8 m (6 ft) and the receptacle is located to avoid physical damage. (C) Fixed equipment shall be permanently connected and fastened in place.

625.54 Ground-Fault Circuit-Interrupter Protection for Personnel. All receptacles installed for the connection of electric vehicle charging that are rated 125 volts, single phase, 15, 20, or 30 amperes shall have ground-fault circuit-interrupter protection for personnel.

625.48 Interactive Systems. Electric vehicle supply equipment and other parts of a system, either on-board or off-board the vehicle, that are identified for and intended to be interconnected to a vehicle and also serve as an optional standby system or an electric power production source or provide for bidirectional power feed, shall be listed as suitable for that purpose and shall comply with Article 705.

Article 630 — Electric Welders

630.11(A) Individual Welders (AC Transformer and DC Rectifier Arc Welders). The ampacity of the supply conductors shall be not less than the current values determined by multiplying the rated primary current by the factor from Table 630.11(A) based on the duty cycle of the welder:

The logic is duty-cycle diversity: a welder that operates only 30 percent of the time heats its supply conductors far less than its rated primary current would suggest.

630.11(B) Group of Welders. The ampacity of conductors that supply a group of welders shall be permitted to be less than the sum of the currents, based on 100 percent of the two largest welders, plus 85 percent of the third largest, plus 70 percent of the fourth largest, plus 60 percent of all remaining welders.

630.12 Overcurrent Protection. (A) For Welders. Each welder shall have overcurrent protection rated or set at not more than 200 percent of the rated primary current, with the next higher standard rating permitted where the value does not correspond to a standard size. Overcurrent protection is not required where the welder is provided with integral protection. (B) For Conductors. Conductors that supply one or more welders shall be protected by an overcurrent device rated or set at not more than 200 percent of the conductor ampacity.

630.13 Disconnecting Means. A disconnecting means shall be provided in the supply circuit for each arc welder that is not equipped with a disconnect mounted as an integral part of the welder. The disconnecting means shall be a switch or circuit breaker, and its rating shall be not less than that necessary to accommodate overcurrent protection as specified under 630.12.

630.31 and 630.32 contain the parallel rules for resistance welders, using a different set of multipliers based on the duty cycle in Table 630.31(A)(2).

630.15 Grounding of Welder Secondary Circuit. The secondary circuit conductors of an arc welder, consisting of the electrode conductor and the work conductor, shall not be considered as premises wiring for the purpose of applying Article 250.