Let the magic smoke out of electrical components

taiwanluthiers

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I think it bears repeating, I blew the breaker when wiring up some contactors because this contactor has nonstandard designs. So when I pushed the start button instead of starting anything up I ended up letting sparks fly and blew the breaker for the whole house. Turns out the contactor has their coil leads on both the top and the bottom of the contactor (normally there's L1 at top, and L2 at bottom), and I just happened to wire both L1 and L2 at the same side at the top and the bottom (thinking that they are just two leads of the same side) and created a short.

Now I have to see if I let the magic smoke out of anything...

For the record I was trying to automate the start capacitor disconnect of a static phase converter. Otherwise I had to throw a frankenstein switch then cut it off shortly after. I still got the job done but did not use the main contactor for turning the phase converter on thinking I might have smoked it. So I still used the original frankstein switch on the phase converter...
 
Oh , that's not good!
Question, why would the whole house breaker go? Is this not on its own circuit? Not trying to be mean, but Might be time to call an electrician to check over everything.
Martin
 
I don't know... but all the breakers in the path tripped. I guess it depends on which one sees the short first or something.
 
Always do meter checks before applying power :)
Be certain of contacts and coil terminals beforehand and write them down
 
For the record, coil connections are A1 and A2
L1,L2,L3 are line in
T1,T2,T3 are motor connections
13,14 are auxiliary normally open
21,22 are auxiliary normally closed
 
Wow! To blow the main house breaker as well as all intermediate breakers must mean you pulled some SERIOUS current through that contactor. The only way that happens is if you pulled 300%+ of the highest breaker rated current and tripped all the breakers on magnetic trips (as opposed to the "slower" thermal trips). If you have a 200A panel then you probably pulled 600A or more.

Breakers did what they are supposed to, so that is good. I'm still surprised you could get that much instantaneous current into the house. You must have a sizeable transformer upstream without too much run to your house. Nearby business or school perhaps?
 
Wow! To blow the main house breaker as well as all intermediate breakers must mean you pulled some SERIOUS current through that contactor. The only way that happens is if you pulled 300%+ of the highest breaker rated current and tripped all the breakers on magnetic trips (as opposed to the "slower" thermal trips). If you have a 200A panel then you probably pulled 600A or more.

Breakers did what they are supposed to, so that is good. I'm still surprised you could get that much instantaneous current into the house. You must have a sizeable transformer upstream without too much run to your house. Nearby business or school perhaps?
I'm located in an industrial area. Main breaker is 70 amp. Neighbors have more than 200 amp three phase, at least most of them, a nursing home across the street.

Good thing I didn't trip anything beyond the main breaker because I'm sure everyone would be ****** at the power outage.
 
Just my guess, since it was a dead short across the power lead, most likely no damage to the components.

Unrelated but similar, while wiring a generator transfer panel for my home, I decided to add a power back alarm. It was pretty simple, so I was working hot. I dropped a hot 16 ga. wire that grounded against the box. It didn't melt the wire, it didn't blow the breaker for that circuit, nor did it blow the mains. It didn't even blow the fuses on the transformer, it blew the transfomer itself. The PG&E repairman told me I was lucky. The transformer was obviously on its last leg and if it had gone out when there was snow on the ground it could have been weeks before they could replace it.
 
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