ABB Enclosed Disconnects

NEC Code 2011 Disconnect Requirements



Articles 422 through 450


422.31 Disconnection of Permanently Connected Appliances (A) Rated at Not Over 300 Volt-Amperes or 1/ 8 Horsepower For permanently connected appliances rated at not over 300 volt-amperes or1/ 8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means. (B) Appliances Rated Over 300 Volt-Amperes or 1/ 8 Horsepower For permanently connected appliances rated over 300 volt-amperes or 1/ 8 hp, 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 or is capable of being locked in the open position. The provision for locking or adding a lock to the disconnecting means shall be installed on or at the switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lock installed.


Section 422.31(B) has been expanded to increase safety to maintenance and service personnel working on electrical appliances. The requirement now provides detailed information pertaining to the method of providing the disconnection required by 


Article 422, Part III. A device that is attached to the circuit breaker handle by a set screw is not an acceptable means to serve as a safe method of locking the device in the off position. The device must have provisions for placement of a lock on it to secure the device in the off position. The lock-out device must be part of the disconnect assembly and must remain in place after the padlock is removed, whether it is a fused disconnect switch, a single circuit breaker, or a circuit breaker in a panelboard.

422.32 Disconnecting Means for Motor-Driven Appliance If a switch or circuit breaker serves as the disconnecting means for a permanently connected motor-driven appliance of more than 1/ 8 hp, it shall be located within sight from the motor controller and shall comply with Part IX of Article 430.

The NEC used the terms in sight from, within sight from, or within sight of the mean the same thing.. terms mean that the equipment must be visible and within fifty feet. Not further than 50 feet There must be a clear line of sight between two pieces of equipment Video - Article 110 for Locking Disconnects One of the changes in the 2014 edition of the National Electrical Code (NEC) was a new section in Article 110 pertaining to lockable disconnecting means. This is significant because a number of sections throughout the Code contain requirements for disconnecting means. It is important to have a good understanding of these requirements


For example, 430.102(B) and (B)(1) state a disconnecting means is required to be located in sight from the motor location and the driven machinery location. Article 100 is needed to clarify the meaning of the term “in sight from” used in this section. As stated in Article 100, where the NEC specifies that one piece of equipment shall be “in sight from,” “within sight from,” “within sight of,” and so forth, the specified equipment is to be visible and not more than 50 feet from the other. In accordance with the main rule in 430.102(B)(1), a disconnecting means (for the motor) shall be visible and located no more than 50 feet from the motor (see Figure 1).