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Why did my 50 amp breaker trip?

mtlogcabin

mtlogcabin

SAWHORSE
Joined
Oct 17, 2009
Messages
9,536
Location
Big Sky Country
Last night the power went out in my area. I was in the master bedroom upstairs with the lights on watching a DVD and a 1500 watt heater plugged into the wall. Nothing else was on anywhere in the house. This morning i wake up still no power until I go down stairs and the clocks are flashing on the stove and microwave. I check the breaker box and find the 50 amp breaker feeding my upstairs sub-panel tripped.

Any ideas as to why the 50 amp breaker would trip with that little load on it? I thought maybe a power spike but really have no idea but I do need to calm my wife's fear that the house is going to burn down.
 
Sounds like a spike to me as well, especially if everything is back on this morning and

functioning normally. Trying to calm your wife's perceived fears is another story! :eek:

.
 
I would be inclined to ask an electrician.

A spike would result in an increased voltage but I believe that what triggers circuit breakers is amperage which would have to be due to something downstream of the circuit breaker.

The fact that your downstairs clocks were flashing suggests that there might have been an problem with a power outage at the pole.

A bad circuit breaker couled trip at a low load.

A simple test would be to turn off all of the circuit breakers in the main panel except the one to the upstairs. Then turn off everything upstairs and check the meter. If the meter continues to move then you might have a short that normally is not enough to trigger the circuit breaker. An electrician should have a meter that allows him to measure the amount of current you are drawing.
 
Builder Bob said:
Are you having any problems with lights dimming or suddenly getting bright - an open neutral can cause power surges and spikes as well
Click to expand...
Open neutrals burn up things in your house but I have never seen it trip a breaker.

Normally a breaker won't trip from the line side but I suspect there was an anomaly with the outage- I cannot explain it.
 
Found it today It tripped again so I went right to the 50 amp breaker one wire was hot to touch and the other cold. I checked the lugs and found the one with the hot wire had a stripped screw that I could not tighten. Installed new breaker
 
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