Stumped by the Code? Receptacle Outlets Installed on Permanently Installed Baseboard Electric Heaters
All questions and answers are based on the 2017 NEC.
Q. What does the Code allow in regard to receptacle outlets installed on permanently installed baseboard electric heaters?
A. If a permanently installed electric baseboard heater has factory-installed receptacle outlets, the receptacles aren’t permitted to be connected to the heater circuits [Sec. 424.9]. Informational Note: Listed baseboard heaters include instructions that prohibit their installation below receptacle outlets.
Q. According to the NEC, overcurrent protection devices must be placed at what location in branch-circuit or feeder conductors?
A. Except as permitted by Sec. 240.21(A) through (H), overcurrent protection devices must be placed at the point where the branch-circuit or feeder conductors receive their power. Taps and transformer secondary conductors aren’t permitted to supply another conductor (tapping a tap isn’t permitted) [Sec. 240.21] (Figure).
Branch-circuit tap conductors are permitted in accordance with Sec. 210.19 and can have overcurrent protection as required by Sec. 210.20 [Sec. 240.21(A)].
Conductors can be tapped from a feeder (feeder taps) as specified in Sec. 240.21(B)(1) through (B)(5). The “next size up overcurrent protection rule” of Sec. 240.4(B) isn’t permitted for tap conductors [Sec. 240.21(B)].
10-ft feeder tap rule
Feeder tap conductors up to 10 ft long are permitted without overcurrent protection at the tap location if the tap conductors comply with the following [Sec. 240.21(B)]:
(1) The tap conductors must have an ampacity not less than:
a. The calculated load in accordance with Art. 220, and
b. The rating of the overcurrent protection device termination or equipment containing overcurrent protection devices supplied by the tap conductors. Exception to (b): Listed equipment, such as a surge protection device, can have their conductors sized in accordance with the manufacturer’s instructions.
(2) The tap conductors must not extend beyond the equipment they supply.
(3) The tap conductors are installed within a raceway when they leave the enclosure.
(4) The tap conductors must have an ampacity not less than 10% of the rating of the overcurrent protection device that protects the feeder. Informational Note: See Sec. 408.36 for the overcurrent protection requirements for panelboards.
25-ft feeder tap rule
Feeder tap conductors up to 25 ft long are permitted without overcurrent protection at the tap location if the tap conductors comply with the following [Sec. 240.21(B)(2)]:
(1) The ampacity of the tap conductors aren’t permitted to be less than one-third the rating of the overcurrent protection device that protects the feeder.
(2) The tap conductors terminate in an overcurrent protection device rated no more than the tap conductor ampacity in accordance with Sec. 310.15 [Table 310.15(B)(16)].
Outside feeder taps of unlimited length rule
Outside feeder tap conductors can be of unlimited length, without overcurrent protection at the point they receive their supply, if they comply with all of the following [Sec. 240.21(5)]:
(1) The outside feeder tap conductors are protected from physical damage within a raceway or manner approved by the authority having jurisdiction.
(2) The outside feeder tap conductors terminate at a single overcurrent protection device that limits the load to the ampacity of the outside feeder tap conductors.
(3) The terminating overcurrent protection device for the outside feeder tap conductors is part of the building feeder disconnect.
(4) The building feeder disconnecting means is readily accessible, either outside the building, or nearest the point of entrance of the outside feeder tap conductors.
These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.
