Special Equipment (Minnesota Class A Journeyworker)

Learning Objectives

Apply the sign and outline lighting rules of Article 600 and the cord-and-plug limits of Article 605 for office furnishings.

Navigate Article 620 for elevators, escalators, moving walks, and platform lifts, and state the electric vehicle and welder rules of Articles 625 and 630.

Apply the information technology equipment room rules of Article 645 and the irrigation machine rules of Article 675.

Apply Articles 680, 690, 694, and 695 to pools and spas, photovoltaic systems, wind electric systems, and fire pumps.

7.1 Electric Signs and Outline Lighting (Article 600)

600.5(A)(2) — sign and outline lighting outlets need a branch circuit rated at least 20 amperes, supplying no other load.

600.5(C)(1) — branch circuits supplying neon tubing installations shall not be rated in excess of 30 amperes.

600.5(C)(2) — branch circuits supplying all other signs and outline lighting shall not exceed 20 amperes; signs are continuous loads for calculations.

600.21(A) — ballasts, transformers, electronic power supplies, and Class 2 power sources must be accessible and securely fastened in place, with a working space of 900 mm (3 ft) high by 900 mm (3 ft) wide by 900 mm (3 ft) deep at each unit under 600.21(D).

600.21(F) — ballasts, transformers, and electronic power supplies above suspended ceilings must have enclosures securely fastened in place and not dependent on the suspended-ceiling grid for support, and shall not be connected to the branch circuit by flexible cord.

7.2 Office Furnishings (Article 605)

Under 605.9, freestanding-type office furnishings — or groups that are electrically connected and mechanically contiguous — may use a single flexible cord and plug, provided:

605.9(A) — the cord is extra-hard usage type with 12 AWG or larger conductors, not over 600 mm (2 ft) long.

605.9(B) — the supplying receptacle is on a separate circuit serving only the office furnishing, within 300 mm (12 in.).

605.9(C) — the furnishing or group contains not more than 13 15-ampere, 125-volt receptacles.

605.9(D) — multiwire circuits are not permitted.

The group shall not exceed 9.0 m (30 ft) when assembled.

7.3 Elevators, Dumbwaiters, Escalators, Moving Walks, Lifts, and Chairlifts (Article 620)

620.5 — live parts must be enclosed against accidental contact in hoistways, at landings, in or on elevator and dumbwaiter cars, in escalator and moving walk wellways, and in platform lift and stairway chairlift runways and machinery spaces; the informational note to 620.5 points to 110.27 for guarding of live parts at 1000 volts, nominal, or less.

620.6 — working space must be provided about controllers, disconnecting means, and other electrical equipment in accordance with 110.26(A). Working clearances in an elevator machine room are therefore the 110.26 spaces about electrical equipment, not a separate elevator dimension.

620.12(B) — conductors other than those integral to control equipment must be at least 24 AWG copper, though smaller listed conductors are permitted. Traveling cables: (A)(1) at least 14 AWG copper or 20 AWG copper or larger in parallel; (A)(2) 24 AWG for communications; (A)(3) 20 AWG copper for other circuits; (A)(4) no more than 3 paralleled, none smaller than 20 AWG.

620.21 — conductors, cables, and optical fiber cables in hoistways, wellways, machinery spaces, machine rooms, and control rooms (excluding traveling cables) must be in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, rigid nonmetallic conduit, or wireways, or be Type MC, MI, or AC cable; flexible metal conduit is limited to 1.8 m (6 ft).

620.24(A) — separate branch circuits supply pit lighting and pit receptacles, and the required lighting shall not be connected to the load side of a ground-fault circuit interrupter; (B) its switch must be readily accessible from the pit access door; (C) the pit needs one 125-volt, single-phase, 15- or 20-ampere duplex receptacle.

620.7(A) — 125-volt, single-phase, 15- and 20-ampere receptacles in pits, in hoistways, on elevator cars of wind turbine tower elevators, on platform lift and stairway chairlift platforms and runways, and in escalator and moving walk wellways must be listed Class A ground-fault circuit-interrupter type; (B) covers machine rooms, control spaces, machinery spaces, control rooms, and truss interiors.

620.34 — supports for cables or raceways in a hoistway, wellway, or runway must be fastened to the guide rail, the escalator or moving walk truss, or the hoistway, wellway, or runway construction.

620.35 — auxiliary gutters installed as part of an elevator installation are not subject to 366.10(C) (length) or 366.22 (number of conductors).

620.36 — optical fiber cables and conductors for operating devices, operation and motion control, power, signaling, fire alarm, lighting, heating, and air-conditioning circuits of 1000 volts or less may be run in the same traveling cable or raceway system, provided all conductors are insulated for the maximum voltage applied to any conductor in the system and all live parts of the equipment are insulated from ground for that voltage; shielded pairs, coaxial cables, and other communications circuits may also be included.

620.37(C) — feeders supplying power to elevators and dumbwaiters must be installed outside the hoistway, except by special permission in an existing hoistway where the feeders contain no splices, or where the driving machine motor is located in the hoistway or on the car or counterweight. Subsections (A) and (B) are the uses permitted in and the wiring method rules for hoistways, machine rooms, control rooms, machinery spaces, and control spaces.

620.53 — a single means must disconnect all ungrounded car light, receptacle, and ventilation conductors, lockable open per 110.25 and located in the machine room or control room for that car; where none exists outside the hoistway, it is outside the hoistway, accessible to qualified persons only, and numbered to the car.

7.4 Electric Vehicle Power Transfer Systems (Article 625)

625.40 — each outlet supplying EVSE greater than 16 amperes or 120 volts must be an individual branch circuit, except as permitted by 625.42(A) or 625.42(B).

625.41 — EVSE, including bidirectional EVSE, is a continuous load; 625.42 requires the supply circuit to have sufficient rating unless the load is limited through controls.

625.54 — all receptacles installed for electric vehicle charging must have ground-fault circuit-interrupter protection for personnel.

625.42(C)(1) — permanently connected EVSE and WPTE outside one- and two-family dwellings need clearly identified emergency disconnect devices not less than 6.0 m (20 ft) nor more than 30.0 m (100 ft) away and in sight, marked "EVSE EMERGENCY DISCONNECT", of the manual reset type, and lockable open.

7.5 Electric Welders (Article 630)

630.11(A) — supply conductor ampacity for an individual arc welder must be at least the I1eff value on the rating plate; where I1eff is not given, it is the rated primary current times the Table 630.11(A) factor for the duty cycle.

Table 630.11(A) — nonmotor generator factors: 100 percent 1.00; 90 percent 0.95; 80 percent 0.89; 70 percent 0.84; 60 percent 0.78; 50 percent 0.71; 40 percent 0.63; 30 percent 0.55; 20 percent or less 0.45; motor generator factors are 1.00, 0.96, 0.91, 0.86, 0.81, 0.75, 0.69, 0.62, and 0.55.

630.11(B) — for a group of welders the minimum ampacity is 100 percent of the two largest, plus 85 percent of the third, plus 70 percent of the fourth, plus 60 percent of the rest.

630.12(A) — each arc welder needs overcurrent protection rated or set at not more than 200 percent of I1max, or of the rated primary current where I1max is not given.

630.13 — a disconnecting means is required in the supply circuit for each arc welder lacking an integral disconnect; it may be a switch, circuit breaker, or listed cord and plug connector.

7.6 Information Technology Equipment (Article 645)

645.6(E) — where the space under a raised floor of approved construction is accessible and openings minimize the entrance of debris, power-supply cords, communications cables, connecting and interconnecting cables, cord and plug connections, and receptacles of the information technology equipment are permitted under the floor, subject to 645.6(E)(1)-(3).

645.6(E)(1)(b) — in addition to 300.25(C): rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, electrical metallic tubing, electrical nonmetallic tubing, metal and nonmetallic wireway, surface raceways, flexible metal conduit, liquidtight flexible metal and nonmetallic conduit, and Type MI cable.

645.10 — an approved means must disconnect power to all electronic equipment in the room, or in designated zones within the room, and a similar means must disconnect all dedicated HVAC systems serving the room or zones and cause all required fire/smoke dampers to close.

7.7 Electrically Driven or Controlled Irrigation Machines (Article 675)

675.7 — where intermittent duty is not involved, Article 430 supplies the ratings for controllers, disconnecting means, conductors, and the like. Where an irrigation machine has inherent intermittent duty, the equivalent current ratings of 675.7(A) and 675.7(B) must be used: 675.7(A) sets the equivalent continuous-current rating for branch-circuit conductors and OCPDs at 125 percent of the nameplate full-load current rating of the largest motor plus a quantity equal to the sum of each of the other motor nameplate full-load currents, and 675.7(B) sets the equivalent locked-rotor current used for the horsepower rating.

675.8(B) — the main disconnecting means must provide overcurrent protection, be at the point of connection of electric power to the machine or in sight from the machine per 110.29, and be readily accessible and lockable open per 110.25, rated not less than the main controller.

675.13 — a machine requiring grounding must have a non-current-carrying equipment grounding conductor as an integral part of each cord, cable, or raceway, sized not less than the largest supply conductor in each; feeder circuits use a conductor sized per Table 250.122.

675.14 — where electrical grounding is required on an irrigation machine, the metallic structure of the machine, metallic conduit, and metallic sheath of cable must be connected to the equipment grounding conductor. Metal-to-metal contact with a part that is already connected to the equipment grounding conductor, and the non-current-carrying parts of the machine, are acceptable bonding paths.

675.15 — if an irrigation machine has a stationary point, a grounding electrode system in accordance with Article 250 Part III must be connected to the machine at that stationary point for lightning protection.

675.22 — the equivalent current ratings of 675.22(A) and 675.22(B) exist specifically for the inherent intermittent duty of center pivot irrigation machines; 675.22(A) gives the equivalent continuous-current rating used to select branch-circuit conductors and devices, and 675.22(B) the equivalent locked-rotor current.

7.8 Swimming Pools, Spas, Hot Tubs, and Fountains (Article 680)

680.5(A) — Article 680's GFCI and SPGFCI requirements are in addition to those in 210.8. 680.5(B) requires a Class A GFCI on receptacles and outlets at 150 volts or less to ground for circuits of 60 amperes or less, single-phase or 100 amperes or less, 3-phase; over 150 volts to ground up to 480 volts phase-to-phase, 680.5(C) requires special purpose GFCI protection at 20 mA or less.

680.8(A) — fixed or stationary equipment, other than underwater luminaires, for a permanently installed pool is permitted to be connected with a flexible cord and plug to facilitate removal or disconnection for servicing; for other than storable pools the flexible cord shall not exceed 900 mm (3 ft) in length, and (B) requires equipment grounding conductors to be connected to a fixed metal part of the assembly.

680.9(B) — communications, radio, and television coaxial cables within Chapter 8 are permitted at not less than 3.0 m (10 ft) above the maximum water level of pools and of diving structures, observation stands, towers, or platforms.

680.11(A) — underground wiring within 1.5 m (5 ft) horizontally of the pool's inside wall is permitted in rigid metal conduit, intermediate metal conduit, rigid PVC conduit, jacketed Type MC cable listed for burial, or listed liquidtight flexible metal or nonmetallic conduit, installed complete between outlets, junctions, or splicing points; (B) it shall not be under the pool unless needed for pool equipment.

680.13 — one or more maintenance disconnecting means must simultaneously disconnect all ungrounded conductors for all utilization equipment other than lighting. Each means must be readily accessible and within sight from its equipment and located not less than 1.5 m (5 ft) horizontally from the inside wall of the pool, spa, fountain, or hot tub, unless separated from the open water by a permanently installed barrier providing a 1.5 m (5 ft) reach path or greater.

680.21(A)(2) — pool-associated motors are permitted to use cord and plug connections, with a flexible cord that shall not exceed 900 mm (3 ft) in length; (A)(1) permits liquidtight flexible metal conduit, liquidtight flexible nonmetallic conduit, or MC cable suitable for the use where flexible connections are needed at or adjacent to the motor.

680.26(B)(1)(a) — general bonding conductors must be solid copper or 40 percent copper-clad steel, insulated, covered, or bare, and not smaller than 8 AWG; (B)(1)(b)(3) requires a 300 mm (12 in.) by 300 mm (12 in.) grid with a tolerance of 100 mm (4 in.) of minimum 8 AWG bare solid conductors bonded at every crossing, secured no more than 150 mm (6 in.) from the outer contour of the shell. The crossings themselves are bonded in accordance with 250.8, whose (A) lists the permitted connection methods: listed pressure connectors, terminal bars, pressure connectors listed as grounding and bonding equipment, exothermic welding, and machine screw-type fasteners.

680.42(A)(1) — listed packaged spa or hot tub assemblies may use liquidtight flexible metal or nonmetallic conduit; 680.42(A)(2) permits a cord not longer than 4.6 m (15 ft) with a GFCI protected connection.

680.43(A) — for an indoor spa or hot tub, one 125-volt, 15- or 20-ampere general-purpose receptacle must be not less than 1.83 m (6 ft) from, and not exceeding 3.0 m (10 ft) from, the inside wall; (A)(1) all receptacles at least 1.83 m (6 ft) away; (A)(2) GFCI or SPGFCI protection within 3.0 m (10 ft); (A)(3) 150 volts to ground maximum; (C) switches at least 1.5 m (5 ft) away.

7.9 Solar Photovoltaic Systems (Article 690)

690.13(D) — the disconnecting means for each PV system installed per 690.4(C) shall be not more than six switches or six sets of circuit breakers in a single enclosure or a group of separate enclosures; 690.12(C)(3) applies the same limit to grouped rapid shutdown initiation devices.

690.13(A) — the PV system disconnecting means must simultaneously disconnect ungrounded PV system conductors from all conductors of other wiring systems; (C) requires the marking "PV SYSTEM DISCONNECT".

690.31(D)(1) — PV dc circuits exceeding 30 volts or 8 amperes inside buildings must be in metal raceways, in Type MC cable complying with 250.118(A)(10)b. or 250.118(A)(10)c., or in metal enclosures; nonmetallic-sheathed cable, electrical nonmetallic tubing, and nonmetallic wireways are not permitted.

7.10 Wind Electric Systems (Article 694)

694.12(B)(1) — wind turbine electric system currents are continuous; 694.12(B)(2) requires conductors and OCPDs to carry not less than 125 percent of the maximum current of 694.12(A), with an exception for assemblies listed for 100 percent continuous operation.

694.22(C)(1) — the disconnecting means must be at a readily accessible location either on or adjacent to the turbine tower, on the outside of a building or structure, or inside at the point of entrance of the wind system conductors; the exception refers to installations complying with 694.30(C), which permit the disconnecting means to be located remotely from the point of entry.

240.4(B) and 240.4(C) — the rating or setting of the wind electric system OCPDs is permitted in accordance with 240.4(B) and 240.4(C). Those conductor-protection rules of Article 240 work together with the 125 percent sizing rule of 694.12(B)(2) rather than being replaced by it: 240.4(B) permits the next higher standard OCPD rating above the conductor ampacity where its conditions are met.

7.11 Fire Pumps (Article 695)

695.5(B)(2)(a)(2) — overcurrent protection must be an assembly listed for fire pump service: it shall not open within 2 minutes at 600 percent of the full-load current of the fire pump motor(s), shall not open with a re-start transient of 24 times that current, shall not open within 10 minutes at 300 percent of it, and shall not be field adjustable.

695.4(F) — transfer between the individual source and one alternate source must take place within the pump room, and (G) requires a transfer switch listed for fire pump service.

695.3 — reconditioned fire pump controllers and transfer switches shall not be installed; 695.4(I) — phase converters shall not be used for a fire pump; 695.4(D)(2) — a tap ahead of the generator disconnect shall not be required.

Code Navigation

Topic	NEC Section	What you find there
Signs	600.5(A)(2), (C)(1), (C)(2), 600.21(F)	20 amperes with no other load; 30 amperes neon; 20 amperes other signs; no grid support
Office furnishings	605.9(A)-(D)	9.0 m (30 ft); 12 AWG, 600 mm (2 ft); 13 receptacles
Elevator wiring and circuits	620.6, 620.12(B), 620.21, 620.24, 620.36, 620.37	Working space per 110.26(A); 24 AWG copper; RMC, IMC, EMT, RNC, wireways, Type MC; separate pit circuits; mixed systems in one traveling cable; feeders outside the hoistway
Elevator disconnects and GFCI	620.7, 620.34, 620.53	Class A GFCI; guide rail supports; single car light disconnect
Reference sections cited alongside elevator, pool, and irrigation rules	110.26(A), 110.27, 240.4(B), 240.4(C), 250.8	Working space about equipment; guarding of live parts; next higher standard OCPD rating; permitted connection methods for grounding and bonding
EVSE and welders	625.40, 625.54, 630.11, 630.12(A)	Individual branch circuit over 16 amperes or 120 volts; 200 percent of I1max
IT equipment rooms	645.6(E), 645.10	Raised-floor cords; electronic equipment, HVAC, fire/smoke dampers
Pools and spas	680.5(B), 680.11, 680.26(B)(1)(b)(3)	60/100 amperes Class A GFCI; 1.5 m (5 ft); 300 mm (12 in.) grid
PV, wind, fire pumps	690.13(D), 694.12(B)(2), 695.5(B)(2)(a)(2)	Six devices; 125 percent; 2 minutes at 600 percent

Common Exam Traps

Swapping the 600.5(C) limits. Neon tubing takes 30 amperes; other signs take 20 amperes, and 600.5(A)(2) requires a 20-ampere outlet supplying no other load.

Confusing the elevator wiring minimum with the traveling-cable minimum. 620.12(B) sets 24 AWG copper and allows smaller listed conductors; 14 AWG and 20 AWG belong to traveling cables under 620.12(A).

Putting elevator pit lighting on the GFCI load side. 620.24(A) states the required lighting shall not be connected to the load side of a ground-fault circuit interrupter.

Reversing the welder duty-cycle factor. A lower duty cycle gives a smaller Table 630.11(A) multiplier: 0.45 at 20 percent or less against 1.00 at 100 percent.

Believing a fire pump breaker may be field adjusted. 695.5(B)(2)(a)(2) prohibits a field-adjustable trip point, and 695.3 prohibits reconditioned controllers and transfer switches.

Treating working clearance in an elevator room as an elevator-only dimension. 620.6 provides working space about controllers, disconnecting means, and other electrical equipment in accordance with 110.26(A), and the informational note to 620.5 sends you to 110.27 for guarding of live parts at 1000 volts or less.

Placing a pool or spa maintenance disconnect beside the water. 680.13 requires each means to be readily accessible, within sight of its equipment, and not less than 1.5 m (5 ft) horizontally from the inside wall unless a permanently installed barrier gives the reach path; 680.8(A) and 680.21(A)(2) both limit the associated flexible cord to 900 mm (3 ft).

Sizing an irrigation machine from Article 430 alone. Where the machine has inherent intermittent duty, the equivalent current ratings of 675.7(A)/675.7(B) (or 675.22(A)/675.22(B) for center pivot machines) govern; when grounding is required, 675.14 bonds the machine's metallic structure, conduit, and cable sheath and 675.15 requires a grounding electrode system at the stationary point.

Practical Field Points

Read the sign outlet requirement before rough-in. The 600.5(A)(2) outlet is a dedicated 20-ampere branch circuit supplying no other load, and signs are continuous loads.

Test elevator pit receptacles as Class A GFCI devices. 620.7(A) covers pits, hoistways, and wellways, while 620.24(A) keeps pit lighting off the GFCI load side.

Label and lock the PV disconnect. 690.13(C) requires the marking and 690.13(D) caps the disconnect at six switches or six sets of circuit breakers.

Verify the fire pump controller listing. The overcurrent assembly must be listed for fire pump service with a non-adjustable trip point holding 2 minutes at 600 percent of full-load current.

Summary

Article 600 caps sign branch circuits at 30 amperes for neon under 600.5(C)(1) and 20 amperes for other signs under 600.5(C)(2). Article 620 sets the elevator wiring minimum at 24 AWG copper under 620.12(B), requires Class A GFCI receptacles in pits under 620.7(A), and keeps pit lighting off the GFCI load side under 620.24(A). Article 625 requires an individual branch circuit above 16 amperes or 120 volts with GFCI protection, and Article 630 caps welder overcurrent protection at 200 percent of I1max. Article 680 requires Class A GFCI at 60 amperes single-phase or 100 amperes 3-phase, a 300 mm (12 in.) bonding grid in 8 AWG, and a 4.6 m (15 ft) spa cord; Article 690 limits the PV disconnect to six devices and requires metal wiring methods over 30 volts or 8 amperes; and Article 695 requires a fire-pump-listed assembly holding 2 minutes at 600 percent and 10 minutes at 300 percent.

Special Equipment