11.1 Signs, Cranes, Elevators, EV Charging, Welders, IT Rooms & Industrial Machinery (Articles 600-670)

Electric signs and outline lighting (Article 600)

Washington (WAC 296-46B-600):

• All signs and outline lighting, regardless of voltage, must be listed or field evaluated.
• A portable outdoor sign needs a weatherproof GFCI receptacle within 6 ft, and extension cords may not supply it.
• LED retrofits of listed signs may be done in place by an 01 general or 04 sign contractor using listed kits, with a required warning label.

Cranes and hoists (Article 610)

• Runway conductor disconnect (610.31): readily accessible and operable from the ground or floor, lockable open, opens all ungrounded conductors, and within sight of the runway contact conductors.
• Crane disconnect (610.32): a motor-circuit switch, breaker, or molded-case switch in the leads from the runway contact conductors, lockable open. It must be readily accessible from the crane cab or operating station unless an exception applies.
• Crane motor conductors are sized with the special tables of 610.14, which account for short-time duty ratings.

Elevators, escalators, and similar equipment (Article 620)

• Main-line disconnect (620.51): a single disconnecting means for each unit disconnects the main power supply to the motor and controller. It must be a fused motor-circuit switch or circuit breaker, lockable open.
• No remote operation: the disconnect may not be opened or closed from any other part of the premises. The one allowance is sprinklers in the hoistway, machine room, or pit: the disconnect may then automatically open the power supply (shunt trip) before water is applied. The disconnect must be within sight of the motor controller.
• Separate branch circuits: car lighting, receptacles, ventilation, and alarms need their own branch circuits (620.22). Machine room and machinery space lighting and receptacles need a separate branch circuit, with the lighting switch at the point of entry (620.23).
• GFCI: 125 V, single-phase, 15 A and 20 A receptacles in pits, in hoistways, and on car tops need GFCI protection (620.85).

Washington (WAC 296-46B-620): the main-line disconnect is inside the machine room door on the strike side, not more than 24 in. from the door to the handle, and 36 to 66 in. above the floor.

Electric vehicle power transfer (Article 625)

Washington: installation of EVSE on public works must be done by people certified through the Electric Vehicle Infrastructure Training Program or a similar nationally recognized program (RCW 19.28.285, 2025). Supervised apprentices are covered when their supervising journey level electrician holds the certification.

Electric welders (Article 630)

Transformer and rectifier arc welders (630.11):

• One welder: supply conductor ampacity is at least the rated primary current multiplied by the Table 630.11(A) factor for the welder's duty cycle. For example, the factor is 1.00 at 100 percent duty cycle and smaller at lower duty cycles.
• A group of welders: conductor ampacity is at least 100 percent of the two largest welders, 85 percent of the third, 70 percent of the fourth, and 60 percent of all the rest (630.11(B)), each based on its individual calculated value.
• Overcurrent protection: each welder is protected at no more than 200 percent of its rated primary current (or I1max). The supply conductors are protected at no more than 200 percent of their ampacity (630.12).
• Resistance welders (630.31): conductors are sized at no less than 70 percent of rated primary current for seam and automatically fed welders, and 50 percent for manually operated nonautomatic welders.

Worked example: a feeder serves four arc welders with calculated values of 40, 35, 30, and 30 A.

• 40 + 35 (two largest at 100%) = 75 A
• 0.85 x 30 (third) = 25.5 A
• 0.70 x 30 (fourth) = 21 A
• Minimum feeder ampacity = 75 + 25.5 + 21 = 121.5 A

Information technology equipment rooms (Article 645)

Article 645 is optional. It applies only if the room meets all the conditions of 645.4:

• a disconnecting means complying with 645.10;
• a dedicated HVAC system (or specific fire and smoke dampers);
• listed IT equipment;
• occupied only by people needed to operate and maintain the equipment;
• separated by fire-resistance-rated walls, floors, and ceilings.

In exchange, it relaxes some wiring rules, such as allowing certain cables under raised floors. The remote disconnect controls (645.10) at approved, readily accessible locations must disconnect power to all electronic equipment in the room and shut down the dedicated HVAC system, unless the critical operations data system alternative applies.

Industrial machinery (Article 670)

• Nameplate (670.3): the machine's nameplate lists the supply voltage, phase, frequency, full-load current, the maximum ampere rating of the short-circuit and ground-fault protective device, the short-circuit current rating, and the largest motor data.
• Supply conductors (670.4(A)): ampacity at least 125 percent of the full-load current of all resistance heating loads, plus 125 percent of the full-load current of the highest-rated motor, plus the full-load currents of all other connected motors and apparatus that may run at the same time.
• SCCR (670.5): the machine may not be installed where the available fault current exceeds its short-circuit current rating.

Other Chapter 6 articles to recognize