422.31(C) Motor-Operated Appliances Rated over 1/8 Horsepower.
Code Change Summary: Disconnection requirements have been simplified for permanently connected, motor operated appliances over 1∕8 horsepower (HP).
Section 422.30 requires a means to simultaneously disconnect each appliance from all ungrounded conductors in accordance with Part III of Article 422. There are several different types of acceptable disconnecting means permitted in Part III (depending on the appliance) In this case, the appliance is operated by a motor rated more than 1/8 HP and is covered in 422.31(C).
The rules in the 2014 NEC® were confusing and appeared to conflict with each other. In the 2017 NEC®, the rules have been set straight and are much easier to read. Now, the disconnecting means must comply with 430.109 and 430.110 (type, amp rating and interrupt capacity). For permanently connected motor-operated appliances with motors rated over 1∕8 hp, the disconnecting means shall be within sight from the appliance or be capable of being locked in the open position in compliance with 110.25.
What isn’t easy to read is the existing exception which was not changed but seems to provide the most controversy, especially when trying to decide if the unit switch for a motor-operated appliance, rated over 1/8 HP, can serve as the actual appliance disconnecting means or if a locking device is required at the circuit breaker. This is a common argument when hard-wiring a dishwasher in a single-family dwelling.
Exception: If an appliance of more than 1⁄8 hp is provided with a unit switch that complies with 422.34(A), (B), (C), or (D), the switch or circuit breaker serving as the other disconnecting means shall be permitted to be out of sight from the appliance.
In order to apply the exception, it needs to be broken down into two parts as follows:
- Compliance with 422.34(A), (B), (C), or (D).
- What is permitted as the “other disconnecting means”.
For the unit switch to comply with 422.34(A), (B), (C), or (D), it must first comply with the parent text of 422.34 which states that the appliance unit switch must have a marked-off position. Some dishwashers have a start-stop button but may not have a marked “off” position.
The permitted type of “other disconnecting means” is dependent on the occupancy type applicable in 422.34. Example: For a single-family dwelling covered in 422.34(C), the disconnect for the appliance could be the unit switch, with a marked-off position, that disconnects all ungrounded conductors as long as there was also a service disconnect for the dwelling in the event that a service technician simply wanted to go and kill the entire service to ensure the circuit being worked on was de-energized.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.
2014 Code Language:
422.31(C) Motor-Operated Appliances Rated over 1∕8 Horsepower. The disconnecting means shall comply with 430.109 and 430.110. For permanently connected motor-operated appliances with motors rated over 1⁄8 hp, the disconnecting means shall meet 422.31(C)(1) or (2).
(1) The branch-circuit switch or circuit breaker shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from the appliance.
(2) The disconnecting means shall be installed within sight of the appliance.
Exception: If an appliance of more than 1⁄8 hp is provided with a unit switch that complies with 422.34(A), (B), (C), or (D), the switch or circuit breaker serving as the other disconnecting means shall be permitted to be out of sight from the appliance.
2017 Code Language:
422.31(C) Motor-Operated Appliances Rated over 1∕8 Horsepower. The disconnecting means shall comply with 430.109 and 430.110. For permanently connected motor-operated appliances with motors rated over 1∕8 hp, the disconnecting means shall be within sight from the appliance or be capable of being locked in the open position in compliance with 110.25.
Exception: If an appliance of more than 1⁄8 hp is provided with a unit switch that complies with 422.34(A), (B), (C), or (D), the switch or circuit breaker serving as the other disconnecting means shall be permitted to be out of sight from the appliance.