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Article 422 covers electric appliances used in any occupancy, if they are fastened in place, permanently connected, or cord and plug. The meat of this article is in Parts II (Installation) and III (Disconnecting Means).
Before installing an appliance, see if it has a label from a recognized labeling authority [90.7]. If it's rated to operate at 50V or more, it must be listed [422.6].
Motor-operated appliances must comply with Article 430, and appliances containing hermetic refrigerant motor compressors must comply with Article 440 [422.3]. Room air-conditioning equipment must be installed per Part VII of Article 440.
GFCI
The following appliances rated not over 250V and 60A, single or three phase, must be GFCI protected [422.5(A)]:
(1) Automotive vacuum machines provided for public use. Figure 01
(2) Drinking water coolers, not drinking water dispensers.
(3) High pressure spray washing machines if cord-and-plug connected.
(4) Tire inflation machines provided for public use.
(5) Vending machines.
The GFCI must be readily accessible, listed, and one or more of the following: [422.5(B)]: Š
(1) GFCI circuit breaker.
(2) GFCI device or receptacle.
(3) GFCI integral with the attachment plug.
(4) GFCI within the supply cord not more than 12 in. from the attachment plug.
(5) Factory installed GFCI within the appliance.
Branch-circuit rating
The branch-circuit ampere rating for an individual appliance can't be less than the branch-circuit rating marked on the appliance [110.3(B)]. The branch-circuit rating for motor-operated appliances must be per 430.6(A) and 430.22. A branch-circuit for an appliance that is not motor-operated, that's a continuous load must be rated not less than 125 percent of the marked ampere rating of the appliance [422.10(A)].
Branch circuits for household ranges and cooking appliances can be sized per Table 220.55 and 210.19(A)(3).
Branch circuits supplying appliances in addition to other loads must be sized as follows [422.10(B)]:
- Cord-and-plug-connected equipment must not be rated more than 80 percent of the branch-circuit ampere rating [210.23(A)(1)].
- Equipment fastened in place must not be rated more than 50 percent of the branch-circuit ampere rating, if the circuit supplies both luminaires and receptacles [210.23(A)(2)].
Overcurrent protection
Branch-circuit conductors must have overcurrent protection per 240.4, and the overcurrent protection device (OCPD) rating must not exceed the rating marked on the appliance [422.11(A)].
For nonmotor appliances, the OCPD must not exceed [422.11(E)]:
(1) The rating marked on the appliance.
(2) 20A if the OCPD rating isn't marked, and the appliance is rated 13.30A or less.
(3) 150 percent of the appliance rated current if the OCPD rating isn't marked, and the appliance is rated over 13.30A. Where 150 percent of the appliance rating doesn't correspond to a standard OCPD ampere rating listed in 240.6(A), the next higher standard rating is permitted.
Central heat
An individual branch circuit must supply central heating equipment [422.12].
- Ex 1: Auxiliary equipment to the central heating equipment, such as pumps, valves, humidifiers, and electrostatic air cleaners, can be connected to the central heater circuit.
- Ex 2: Permanently connected air-conditioning equipment can be connected to the individual branch circuit that supplies central heating equipment.
Install electric space-heating equipment per Article 424.
Storage water heaters
An electric water heater having a capacity of 120 gallons or less is considered a continuous load for the purpose of sizing branch circuits [422.13]. Branch-circuit conductors must have a rating of at least 125 percent of the ampere rating of the load [422.10]. Size the OCPD per 422.11(E)(3) if the manufacturer doesn't provide the minimum OCPD size [422.11(A)].
Central vacuums
Listed central vacuum systems must be on a separate circuit if the rating of the equipment exceeds 50 percent of the ampere rating of the circuit in accordance with 210.23(A) [422.15].
Section 210.23(A)(2) specifies that equipment fastened in place, other than luminaires, must not be rated more than 50 percent of the branch-circuit ampere rating if this circuit supplies both luminaires and receptacles. Thus, a separate 15A circuit is required for a central vacuum receptacle outlet if the rating of the central vacuum exceeds 7.5A. A separate 20A circuit is required for a central vacuum receptacle outlet if the rating of the central vacuum exceeds 10A, but not 16A.
Flexible cords
Flexible cords are permitted to facilitate [422.16(A)]:
(1) Frequent interchange, or to prevent the transmission of noise and vibration [400.10(A)(6) and 400.10(A)(7)].
(2) Removal of appliances fastened in place, where the fastening means and mechanical connections are specifically designed to permit ready removal [400.12(A)(8)].
Flexible cords are permitted for specific appliances as follows [422.16(B):
A flexible cord is permitted for an in sink waste disposer if the [422.16(B)(1)]:
(1) Flexible cord has a grounding type attachment plug.
(2) Flexible cord length is between 18 in. and 3 ft.
(3) The receptacle is located so as to protect against damage to the flexible cord.
(4) The receptacle is accessible.
A flexible cord is permitted for a dishwasher or trash compactor if the flexible cord has a grounding type attachment plug [422.16(B)(2)(1).
- Receptacles must be located so as to protect the flexible cord from physical damage [422.16(B(2)(4).
For a trash compactor, the flexible the length of the flexible cord must be between 3ft and 4 ft, measured from the rear plane of the appliance [422.16(B)(2)(2)]. The receptacle must be in the space occupied by the trash compactor or in the space adjacent to the trash compactor [422.16(B)(2)(5)].
For a built in dishwasher, the length of the flexible cord must be between 3 ft and 6 ft 6 in., measured from the face of the attachment plug to the plane of the rear of the appliance [422.16(B)(2)(3)]. The receptacle must be in the space adjacent to the space occupied by the dishwasher [422.16(B)(2)(6)]
Wall mounted ovens and counter mounted cooking units can be cord and plug connected [422.16(B)(3).
Range hoods can be cord and plug connected if all of the following are met [422.16(B)(4)]:
(1) The flexible cord for the range hood terminates with a grounding type attachment plug
(2) The length of the flexible cord for the range hood is between 18 in. and 48 in.
(3) The receptacle for the range hood is located so as to protect it from physical damage.
(4) The range hood receptacle is accessible.
(5) The range hood receptacle is supplied by an individual branch circuit.
Paddle fans
Ceiling paddle fans must be supported independently of an outlet box or by one of the following [422.18]:
(1) A listed outlet box or listed outlet box system marked as suitable for ceiling paddle fan support of not more than 70 lb. Outlet boxes for a ceiling paddle fan that weighs more than 35 lb must include the maximum weight to be supported in the required marking per 314.27(C).
(2) A listed outlet box system, locking support and mounting receptacle, and compatible factory installed attachment fitting designed for support, identified for the use, and installed per 314.27(E).
Disconnecting means
Each appliance must have a means that disconnects simultaneously all ungrounded circuit conductors [422.30].
For 300 VA or 18 horsepower or less appliances, a circuit breaker can serve as the disconnect means if it's one of the following [422.31(A)]:
- Within sight from the appliance.
- Lockable with provisions for locking to remain in place whether the lock is installed or not per 110.25.
For permanently connected appliances rated over 300 VA, a switch or circuit breaker meeting either of the above requirements can serve as the disconnect means [422.31(B)].
For motor operated appliances rated over 18 horsepower, you have to use an actual disconnect (not a switch or breaker), and it must meet either of the above requirements [422.31(C)].
Ex: An appliance of more than 1/8 hp containing a unit switch that complies with 422.34 can serve as the disconnecting means.
The disconnection of an accessible cord-and-plug connection or attachment fitting connection of the appliance can serve as the appliance disconnecting means. [422.33(A)].
Doing a good job
For any type of appliance, certain rules always apply. For example, install GFCI protection where required [422.5]. Some types of appliances have specific requirements for overcurrent protection [422.11(B) through (G)]. Additional requirements may affect your installation [422.12 through 422.48], depending on what you're installing and whether you're using flexible cord. Characterize the installation, then follow the rules that apply to it.
Code compliance is only one requirement for doing a good job. It's also important to pay attention to the details of craftsmanship. For example, you install a flexible cord to an undercounter dishwasher. Pull the extra on through the hole and loop it nicely behind the dishwasher, rather than have it bundled up under the sink.
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