20amp SqD QO burnout....and breaker life poll!
From my Private Idaho thread...
Yesterday after installing a new circuit for my master bedroom, I was using a receptacle on the new circuit to run my shop vac and clean up.
After about 10 minutes or so, the vac suddenly quit. I shut it off, turned it back on and it only ran for a second or so then quit again.
I went to the panel to check the breaker to see if it tripped for some reason...the Visi-Trip wasn't showing. Huh. So I tried to reset it but the handle just flopped like it wasn't connected to anything....and the breaker felt warm.
I moved the circuit to another breaker and it worked fine.
So today I took the bad breaker apart and found a few surprises:
Lots of arc damage, the braided pigtail had burned off of the overload element:
![]()
Notice all the arc damage on the overload element on the left side of the left half:
![]()
All of the current carrying parts and the Visi-Trip, all are damaged badly, note the condition of the fixed contact (bottom left):
![]()
My thought on this is that this breaker had been subjected into multiple closings into a fault (as evidenced by the damage to the fixed contact and the movable contact), and the braided pigtail was weakened and finally failed under the load of the shop vac.
This was one of the original breakers in the panel (from roughly 1981-83 based on the inspection tag). Because of this, and the fact that I am anal about how a panel looks I plan on replacing ALL of the old breakers to prevent this from happening again.
I also want to point out that, I feel this is a graphic example of two "rules":
Yesterday after installing a new circuit for my master bedroom, I was using a receptacle on the new circuit to run my shop vac and clean up.
After about 10 minutes or so, the vac suddenly quit. I shut it off, turned it back on and it only ran for a second or so then quit again.
I went to the panel to check the breaker to see if it tripped for some reason...the Visi-Trip wasn't showing. Huh. So I tried to reset it but the handle just flopped like it wasn't connected to anything....and the breaker felt warm.
I moved the circuit to another breaker and it worked fine.
So today I took the bad breaker apart and found a few surprises:
Lots of arc damage, the braided pigtail had burned off of the overload element:
Notice all the arc damage on the overload element on the left side of the left half:
All of the current carrying parts and the Visi-Trip, all are damaged badly, note the condition of the fixed contact (bottom left):
My thought on this is that this breaker had been subjected into multiple closings into a fault (as evidenced by the damage to the fixed contact and the movable contact), and the braided pigtail was weakened and finally failed under the load of the shop vac.
This was one of the original breakers in the panel (from roughly 1981-83 based on the inspection tag). Because of this, and the fact that I am anal about how a panel looks I plan on replacing ALL of the old breakers to prevent this from happening again.
I also want to point out that, I feel this is a graphic example of two "rules":
- Do NOT keep reclosing a breaker into a fault; and
- The reason why some manufacturers say to replace this class of breaker after it has cleared more than two serious faults.
Attachments
1 - 20 of 62 Posts
Joined
·
39,532 Posts
Joined
·
3,452 Posts
Don't you roll your eyes at me.:jester:
Joined
·
6,226 Posts
QO breakers are great, but 30 years, probably loads of time feeding electric space heaters, and probably being reset into faults multiple times, shows what ya get for a $5 circuit breaker. :laughing:
Joined
·
3,452 Posts
Don't you roll your eyes at me:jester:
Joined
·
3,452 Posts
Was this a used QO?
Nope but one of the originals from 1981-83.
Uhhhhh, no....
Yeah like I said it's one of the originals from the early 80's, it was in the panel when I bought the house.
:laughing:Your beginning to worry me MX...againUhhhhh, no....
Yeah like I said it's one of the originals from the early 80's, it was in the panel when I bought the house.
:jester:First thing I would've done would be changing every single breaker to a new sealed in box genuine certified QO. Never reuse old equipment, for that reason. Most QOs fail in the off position, which is all the more reason why I like them.
1 - 20 of 62 Posts
