Changing Circuit Breakers

[Craigv]

You're forgetting the cost of rebuilding and destroyed inventory after the fire because the breakers which were not designed to operate for so many cycles failed and stayed locked on during an overload.

Not impossible, but highly unlikely.

Anecdotal, but: Every time I've replaced a breaker that was used as a switch for years and failed, the complaint was that the breaker was tripping excessively. Checked and found no overload condition in the circuit. Installed new breaker, back in business. Recommend switch install (I like to upsell where it makes sense) and that's usually declined. No further tripping, so we can surmise that the claims manufacturers that their breakers are designed to fail safe is true.

Some plausible facts:
https://electrical-engineering-port...cuit-breakers-due-to-the-switching-operations

 

[Frank DuVal]

Yes, I learned this back in the Edison base fuse days. Great tip.

I also use a headlamp with leads to replace a blown fuse in a car for the same troubleshooting tip. Wiggle harness and look for change in headlamp brightness.:thumbsup:

I have a 50 watt 250 volt bulb handed down by my grandfather for use on 240 volt circuit troubleshooting, no need for series 120 volt bull balls....

 

[petersonra]

Cbs are typically only rated for a few, maybe only one, trip from a dead short. if you suspect a dead short is what tripped a breaker changing it out makes sense.

 

[jumper]

Cbs are typically only rated for a few, maybe only one, trip from a dead short. if you suspect a dead short is what tripped a breaker changing it out makes sense.

Two.

 

[Coppersmith]

Two.

Well, there's an upsell opportunity. If you see a tripped breaker, reset it, and it trips again due to a dead short, the breaker should be replaced.

I'd be curious to see documentation of this limit of two trips.

 

[John120/240]

Well, there's an upsell opportunity. If you see a tripped breaker, reset it, and it trips again due to a dead short, the breaker should be replaced.

I'd be curious to see documentation of this limit of two trips.

And I always thought that was what the 15 or 20 number on the handle meant. After 15 trips it is no longer reliable, must replace. /jk

 

[ptonsparky]

And I always thought that was what the 15 or 20 number on the handle meant. After 15 trips it is no longer reliable, must replace. /jk

What if you don’t know? At least twice on this. Older Nutone Heat /vent/light.

 

[jim dungar]

Well, there's an upsell opportunity. If you see a tripped breaker, reset it, and it trips again due to a dead short, the breaker should be replaced.

I'd be curious to see documentation of this limit of two trips.

The two trips is part of the test procedure in UL Listing standards. Ii is based on a maximum bolted fault current value. For a typical residential 20A breaker, this means in can interrupt 10,000A only two times. The test says nothing about how many times it can interrupt a much lower value, like 2000A or even 200A.