Letting the smoke out. Utility phase melting

Status
Not open for further replies.
L

LAmetalbender

Member
Location
Los Angeles, CA, USA
Los Angeles CA. Journeyman Inside Wireman and cable Splicer. 120/208 3p 4wire. On a small building remodel. I notice a plastic smell lingering. The total load during the remodel is a little over 5 amps on average.

i open the cover for the main breaker and find one leg is cooking on the utility side.
no tripped breakers.

Utility has been called.

Any ideas?
 

Attachments

  • image.jpg
    image.jpg
    127.2 KB · Views: 0
Loose connection, or it could have been over torqued and damaged the cable, both would cause arcing.
 
The total load is around three amps and has been that way for two days now. Lights and light power tools. Checked the voltages and they are normal. Uncle Ed (so cal Edison) can tighten or adjust the lugs. Nothing out of the ordinary happened today other than the framers actually got some work done.

Will let let you know. thanks for the responses.
 
The termination bolt looks discolored as well. The loose connection may be in the breaker it self.
 
I don't think the utility is going to be of much help. Terminations on circuit breakers are the customers responsibility. In CA the utilities responsibility ends at the weather head connections for overhead feeds or in underground pull sections for underground feeds.

You state that the load is only 5 amps but this damage has probably occurred over a long period of time when the load was larger. The only acceptable repair is to replace the breaker and cut the wire back to where it is undamaged or replace the wire. Do not just tighten the existing termination.
 
I see this on mains every once in a while. I've never totally figured out if it's a loose connection at the lug or a corroded contact inside the breaker due to never being cycled on/off.
 
curt swartz said:
I don't think the utility is going to be of much help. Terminations on circuit breakers are the customers responsibility. In CA the utilities responsibility ends at the weather head connections for overhead feeds or in underground pull sections for underground feeds.

You state that the load is only 5 amps but this damage has probably occurred over a long period of time when the load was larger. The only acceptable repair is to replace the breaker and cut the wire back to where it is undamaged or replace the wire. Do not just tighten the existing termination.
Click to expand...

Agree. :thumbsup::thumbsup:
 
LAmetalbender said:
Los Angeles CA. Journeyman Inside Wireman and cable Splicer. 120/208 3p 4wire. On a small building remodel. I notice a plastic smell lingering. The total load during the remodel is a little over 5 amps on average.

i open the cover for the main breaker and find one leg is cooking on the utility side.
no tripped breakers.

Utility has been called.

Any ideas?
Click to expand...
Being that the issue is on the line side of the breaker it has no reason to trip. The heating is located at loose line aside terminal. My biggest concern is the damage that could have been done to the breaker. There appears to have been enough heat generated that the heat may have been great enough to conduct to the stationary(lower) contact up to the moving contact and weakening the spring that holds the moving contact closed. The will cause the moving and stationary contacts to eventually fail.
As such it is imperative to be suspect for internal damage that msy have been done.
With the power deenergized remove the cover of the breaker if it isn't sealed grab the arc chute and remove it an inspect that pole for damage.
 
LAmetalbender said:
Los Angeles CA. Journeyman Inside Wireman and cable Splicer. 120/208 3p 4wire. On a small building remodel. I notice a plastic smell lingering. The total load during the remodel is a little over 5 amps on average.

i open the cover for the main breaker and find one leg is cooking on the utility side.
no tripped breakers.

Utility has been called.

Any ideas?
Click to expand...
Mine was a duplicate response so it was deleted.
 
And the winner is

And the winner is

All of you were correct and the suggestions were perfect. Edison came out. They had to open the meter side of the enclosure to disconnect the conductors before the main service disconnect. Once that was done it became easy to find out why. The connection was loose. Not the lug itself but the internal connections within the disconnect. Cool. I told the owner he was buying a new breaker and all he asked for was the receipt. And the framers went home early. All good.

Thank you as always.
 
Status
Not open for further replies.
Top