Electrical issues in a main breaker panel - help

[Anonymous-0]

Last couple of days we have had half the power go out in our house with no breakers tripped. The power eventually comes back on, apparently when the pump-trol switch on the pressure tank for the well flips on.

Today I noticed some "sizzle" and "crackle" noises in the main breaker box. So I tested for a hot panel, shut the main breaker off, and took a look under the panel front cover. I found that some significant arcing has been going on at the point that one of the line-in wires is going into the main breaker, which is a SquareD 2-pole 240V/150A main. By the smoke marks around the terminal on the breaker and the panel area behind it, it looks like the arc is occurring between the line-in terminal and the panel itself, over about a 1in gap.

I tested all the load circuits for shorts and didn't find any, so I know the problem is at the panel or before that point. I suspect the main breaker since that is where the arcing is occurring. Any other ideas? Or should I just go ahead and try a new main breaker?

 

[Tramway Guy]

Aluminum wire going in to the breaker??? Sounds like either the wire is broken or oxidized or the terminal is loose or something in the breaker is bad.
I am not an electrician, however.

 

[Stephen Newell]

Sometimes when the screws are't tightened down good enough it will burn up the breaker. It sound like you just need a new main breaker. If you have enough slack on the wire, cut some off so you have a fresh end to use.

 

[Anonymous-0]

Yes, AL line-in wire.

 

[Philip Doolittle]

#1 Be very careful because you are working on a HOT- ENERGISED panel where you can get Shocked,ARC FLASH BURNED,or killed !!! #2 If you are not experienced or qualfied DO NOT ATTEMPT to do this yourself. #3 You will need to shut off the incoming Electrical power. Depending on your Electrical Service provider (REMC,Public or private Elec. Service Company) YOU should CONTACT THEM IMMEDIATELY to disconnect service or pull the electric meter ! PLEASE DO NOT ATTEMPT TO PULL THE METER YOURSELF. You could make an additional problem. #4 With the incoming power Off, check with a good meter that there is NO Electrical Power on ANY of the service conductors or to ground. At this point you can then investigate the damage and correction(s) to be made. To advise further you need PHOTO'S of the panel for any suggestions as to repair or replacement. Please email me for further help or advice. This advice is from an Professional Electrical Eng'r with 45 yr's of experience in this field and are only suggestions, if in doubt hire a Licensed Electrican

 

[Mike M]

Sounds similar to what I just wnet through this weekend.
See tractor talk "100 amp main" started on friday and I posted some updates. Got lots of good advice and even caused a fight ! Ya I know what else is new ? LOL

 

[Anonymous-0]

Thanks for the advice Philip, much appreciated! I am aware that the panel is hot when the arcing occurs, and I have taken appropriate precautions to protect myself while working on the panel. I have called the power company and will be coordinating a disconnection at the meter with them, that is their turf anyway. I'll send you a couple photos via email.

 

[buickanddeere]

Good to hear you are correctly handling the issue. Too often "myway" is more important than the right way. Check the neutral Connections when everything is apart. It is possible to over tighten an aluminum connection and cold forge the AL into trouble.

 

[jbp]

Better call a qualified electrician before you have to call the fire department.

 

[paul]

What Phillip said, sounds like you are on the good path.

Al service wire is good, but it needs the right grease on it and be connected to the right type of connectors. It likes to expand and contract a lot, and an oxide (rust if it were iron...) likes to form on it, and it will oxide worse if it is in contact with the wrong type of connectors - dissimilar metals type of issues.

Any f that leads to arcing and heating which keeps making itself worse.

Sounds like some of that might be going on, but wouldn't really know unless we see it up close and personal? Once it's arcing, it can mess itself up with pitting to where you need to start fresh, can't just grease it and tighten down. The metal changes some, or erodes away to where you can't get a good connection.

Glad you are getting the good folks involved, might cost a few bucks but will let you sleep peacefully at night and family & friends & belongings will remain safe.

--->Paul

 

[Pappy]

Our shop has 100 amp service wire supplied by the power company. We use a 70 amp main breaker.
The lights are on two separate circuits (15 amp).
One day, half the lights would not turn on, but when I turned on the air compressor, (220 volt) all the lights came on. Feedback through air compressor. New breaker cured the problem.

 

[John T]

Okay, sounds like a loose arcing connection (wiring terminations or breaker or both).

NOTE unless you pull the meter those two big input wires that connect into lugs up near the main breaker ARE HOT MIND YOU theres 240 volts across them and 120 volt from either to Neutral or case Ground.

A possibility, especially if aluminum wire is used, is a loose connection or perhaps the aluminum anti oxidant isnt there or the terminals arent torqued properly and there has been burning arcing heat and wire deterioration where the lead in hot wires are secured ID CHECK THAT FIRST and then reconnect the wires using anti oxidant and torque to the correct value.

In a previous discussion the loose connection was where the main braker plugged in and the bars had burned arced and deteriorated. In that case a good clean up and a new tighter fitting breaker might posibly remedy the situation.

In either case for no more then the cost and since breakers can go bad and if yours has been overheating ID GET A NEW MAIN BREAKER

If the connections and incoming wires are burned and pitted Id replace all that and use anti oxidant if aluminum is used and torque to the correct values.

If theres any burning or pitting Id clean all that up

While a it Id check alllllllll connections for tightness and look for evidence or burning arcing or pitting AND INSURE THE NEUTRALS AND GROUNDS ARE INTACT AND TIGHT

IF IN DOUBT OR YOURE NOT COMPETENT TO FIX THIS HIRE AN EXPERIENCED COMPETENT QUALIFIED PROFESSIONAL ELECTRICIAN and since he can be there to actually look and see whats wrong (and we cant) VALUE HIS OPINION OVER ANY OF OURS

John T

 

[dhermesc]

X2

That would have been the first thing I did before turning on my computer to ask about it on this website.

 

[barnE]

Make sure lugs have dual AL/CU if you are using aluminum wire. No markings means only Copper. Dave