Your most pressing National Electrical Code (NEC) questions answered:
All questions and answers based on the 2017 NEC.
Underlined text indicates a change in the rules for the 2017 NEC.
Q. Where does the Code require the use of tamper-resistant receptacles?
A. Nonlocking-type 15A and 20A, 125V and 250V receptacles in the following areas must be listed as tamper resistant [406.12]:
(1) Dwelling unit areas specified in Sec. 210.52 and Sec. 550.13
(2) Hotel and motel guest rooms and guest suites
(3) Child care facilities (Note: A childcare facility is a building or portions thereof used for educational, supervision, or personal care services for five or more children seven years in age or less [406.2].)
(4) Preschools and elementary education facilities
(5) Business offices, corridors, waiting rooms and the like in clinics, medical and dental offices, and outpatient facilities.
(6) Places of awaiting transportation, gymnasiums, skating rinks, and auditoriums
Informational Note: Receptacle types covered by this requirement are identified as 5‑15, 5‑20, 6‑15, and 6‑20 in NEMA WD 6, Wiring Devices—Dimensional Specifications.
Exception to (1) through (7): Receptacles in the following locations aren’t required to be tamper resistant:
(1) Receptacles located more than 5½ ft above the floor.
(2) Receptacles that are part of a luminaire or appliance.
(3) A receptacle located within dedicated space for an appliance that in normal use isn’t easily moved from one place to another.
(4) Nongrounding receptacles used for replacements as permitted in Sec. 406.4(D)(2)(a).
Q. What are the Code requirements for a dwelling unit garage branch circuit?
A. In each attached garage and each detached garage with electric power, at least one receptacle outlet, located not more than 5½ ft above the floor, is required in each vehicle bay [210.52]. At least one 20A, 120V branch circuit is required to supply the receptacle outlet(s) required by Sec. 210.52 in attached garages and detached garages with electric power. This 20A, 120V branch circuit isn’t permitted to serve any other outlet [210.11(C)(4)] (Figure).
Exception: Readily accessible outdoor receptacle outlets (not lighting outlets) can be supplied by the 20A, 120V garage receptacle branch circuit.
Q. What defines the rating of a branch circuit in the eyes of the NEC?
A. The rating of a branch circuit is determined by the rating of the branch-circuit overcurrent protection device, not the conductor ampacity [210.18]. For example, the branch-circuit rating of 10 THHN, rated 30A at 60°C, protected by a 20A circuit breaker is 20A.
Q. Does the Code allow the use of swimming pool reinforcing steel as part of the grounding electrode system?
A. Swimming pool reinforcing steel for equipotential bonding in accordance with Sec. 680.26(B)(1) and 680.26(B)(2) isn’t permitted to be used as a grounding electrode [250.52(B)(3)].
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See the origial article at: http://www.ecmweb.com/national-electrical-code/stumped-code-use-tamper-resistant-receptacles-requirements