Trippin’- Locked on Circuit Breakers                      Wenatchee Home Inspections

Sometimes you have a conversation and you go… DUH!

I had to think… (really I was not thinking).  Well I should have known the answer without thinking… but such are those brain farts.

There are many applications that you would want a locking mechanism for the breaker to be either locked on or locked off.  This is mainly in a commercial setting known as lock out, tag out (LOTO).

 You want to lock “OFF” when you have to work on a particular circuit. You want to lock “ON” if you do not want a particular circuit to be de-energized by accident- such as emergency lighting or security circuits etc…

You will often see these LOTO devices in residential homes for water heaters and dishwashers that are hardwired and not in line of sight of the means of disconnect.

So the next question is what if something happens and the breaker is locked on?

Breakers are designed to trip internally even if the handle is in the locked “ON” position.

From the National Electrical Code (NEC) for circuit breakers-

240.80 Method of Operation.  
“Circuit breakers shall be trip free and capable of being closed and opened by manual operation. Their normal method of operation by other than manual means, such as electrical or pneumatic, shall be permitted if means for manual operation are also provided.”

The term “trip free” means that a circuit breaker is required to open under overcurrent conditions even when the handle is held or locked in the on position.
 

Ancora Imparo

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

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www.ncwhomeinspections.com          509-670-9572