High leg got mismatched with the 120 leg...should I be replacing the breakers?

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SolarCenTex

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I'll spare the details on how this happened except to say that the utility and my journeyman had a communication gap...original high leg wire was moved by the utility during a reconnect call and put into currently-accepted location (right side of meter). My JM put back with assumption that the high leg was going to stay in the middle position where it originally was...I figured my team's fault really for not checking the voltage with a meter immediately and quickly recognizing the error and miscommunication.

So you might imagine what happened. The stove in this old commercial building didn't get its 240 split phase but a 120 / 208 V combo - burnt. Numerous ballasted lights burnt out. All this replaced by me.

My question for all is should the circuit breakers in the main panel be replaced since the leg received high voltage stinger leg and not the 120V. Will / could a breaker be damaged and is it good practice to replace the 20 or so breakers in the panel out of an abundance of caution?

I have not checked the labeling of each breaker but I suspect they are 120/240 dual pole breakers and the single poles (of which there are many) are 120V rated.

Thanks.:?
 
Why would it fry a straight (3 wire) 240V oven? Or did the stinger get connector to the 120V line that is used for the electronics (4 wire oven)?

I wouldnt think the breakers got hurt, just more a listing issue that a slash rated breaker cannot see more than 120V->ground.
 
Stinger leg was reconnected to the 120 leg

Stinger leg was reconnected to the 120 leg

JFletcher said:
Why would it fry a straight (3 wire) 240V oven? Or did the stinger get connector to the 120V line that is used for the electronics (4 wire oven)?

I wouldnt think the breakers got hurt, just more a listing issue that a slash rated breaker cannot see more than 120V->ground.
Click to expand...

Stinger went to a leg that should have been 120V. So yes, those breakers did see more than 120 V to ground, hence my question.
 
I don't think it is an issue for the breakers unless they interrupted high fault current. It is my understanding is that one pole can see more fault current than it was designed for when you use a slash rated breaker on a wild leg system under some fault conditions.

Just the voltage will not be an issue.

A couple of year ago we found a 480 volt panel and found a 240 volt rated breaker that had been in the panel for many years... it was replaced with a correctly rated breaker as part of the project, but there was no apparent issue with it.
 
I agree, voltage ratings on LV breakers matter because it changes how much energy the breaker must interrupt.

A non-electronic breaker will not be hurt by a 73% overvoltage: To get a UL listing those breakers must pass a hipot at more than 1000% of their nameplate voltage.
 
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