Regulations as to special purpose outlets are as follows.
(A) Cooking unit. The range receptacle shall be surfaced mounted in such a way as to afford protection to the conductors.
(1) NEC Table 220-19 allows a demand factor for electric ranges, wall-mounted ovens, counter-mounted cooking units and other cooking appliances over 1-3/4 kw rating.
(2) A load of only eight kw (8000 watts) may be used for any range rated at not more than 12 kw (12,000 watts). If the range is rated at over 12 kw, start with eight kw. For each kilowatt or fraction thereof above the 12 kw, add 400 watts (or 5% of 8,000 watts).
(B) Hot water heater. The following National Electric Code sections apply to the load demands on a branch circuit by a water heater.
(1) NEC § 422-14(b) states that “all fixed water heaters having a capacity of 150 gallons or less shall be considered a continuous duty load”.
(2) NEC § 422-5(a) exception 2 states that for a continuous load appliance, “the branch circuit rating shall not be not less than 125% of the marked rating” of the appliance.
(C) Clothes dryer. A separate circuit must be provided for an electric clothes dryer.
(1) NEC § 250-45(C) states “clothes dryers must be grounded”, but may be grounded to the neutral of the circuit wire if the grounded conductor is No. 10 AWG or larger.
(2) NEC § 200-18 requires a circuit with a minimum of 5,000 watts’ capacity or a capacity based on the rating of the dryer, whichever is higher. Dryers are usually installed by using a cord and plug and a receptacle, which must be 30 amperes, three- wire.
(D) Dishwasher. The NEC states that a built-in dishwasher and trash compactor intended for use in a dwelling, if provided with a three-conductor cord terminated with a grounding-type attachment plug, shall be permitted if the cord is three to four feet in length, the receptacle is located to avoid physical damage to the cord and is located in an accessible area in the space occupied by the appliance or adjacent thereto. A split receptacle may be used for both a garbage disposer and a dishwasher when located under or near a sink.
(E) Garbage disposer. The NEC requires running overcurrent protection not to exceed 125% of the full load current rating of the motor.
(1) NEC § 442-8(d) permits a three- conductor cord not less than 18 inches or over 36 inches with a grounding type attached plug to be used; provided, the receptacle is accessible and located so as to avoid physical damage to the flexible cord.
(2) A 20-ampere circuit is sufficient for a 120-volt disposer.
(Prior Code, § 152.34)