Replacing outside breaker

[Bill Douglas]

Shaun, this ground screw in the blue square has been getting hot. A lot of current has been ripping through it to ground.

[notmytarga]

+1 on needing more than a 100 AMP service here. Three phase - but you are only using two for that 80 amp leg to your dryer. Checking to make sure that the load is balanced on the three phases might spread the current on the main breakers more equitably. Which of those three breakers linked at the main is the hottest when it trips?? Only one may be seeing the peaks and getting fried in the process - I guess the middle one.

[MBAtarga]

Originally Posted by Bill Douglas

Shaun, this ground screw in the blue square has been getting hot. A lot of current has been ripping through it to ground.

I'm not sure that is ground. I think this is 3 phase service- hence that is 1 of the 3.

[Bill Douglas]

Umm, I don't know what it is but current has been ripping through that screw getting it hot, very hot, and it shouldn't.

[Shaun @ Tru6]

wouldn't the black soot feathering out mean sparking? When I think of signs of heat, I see a weld pattern as evidence. this looks different. I can take more pics if anyone wants.

[Bill Douglas]

I had a wire going to the buss bar in the house that wasn't screwed on tightly enough and it had markings something like this. It had got hot enough to melt the plastic on the wire. When I talked to an electrican about it he said something along the lines of very bad and can lead to a house fire. Gulp.

Either way black soot shouldn't be there. For a start maybe (carefully) remove the screw and wire brush the area and do it up firmly, but remember there could be current going through it.

[Shaun @ Tru6]

Originally Posted by notmytarga

+1 on needing more than a 100 AMP service here. Three phase - but you are only using two for that 80 amp leg to your dryer. Checking to make sure that the load is balanced on the three phases might spread the current on the main breakers more equitably. Which of those three breakers linked at the main is the hottest when it trips?? Only one may be seeing the peaks and getting fried in the process - I guess the middle one.

Should I get a larger breaker?

[70SATMan]

Originally Posted by Shaun 84 Targa

wouldn't the black soot feathering out mean sparking? When I think of signs of heat, I see a weld pattern as evidence. this looks different. I can take more pics if anyone wants.

Yep. Could be corrosion between the plates has created high resistance causing the potential to arc across the lower resistance conductor to the plate which is through the screw.

Shaun, is this box only acting as your main disconnect which then routes three phase to another panel???? If so, does your other panel have another three phase main breaker??

If this is your set up I'd think about having that box fully replaced with a switch blade disconnect with in line phase fuses instead of just replacing that breaker.

There is more corrosion in there than should be...

[VINMAN]

Originally Posted by Bill Douglas

Shaun, this ground screw in the blue square has been getting hot. A lot of current has been ripping through it to ground.

That is NOT a ground screw! It is the middle phase! ( with a bad connection..)

[70SATMan]

Originally Posted by Shaun 84 Targa

Should I get a larger breaker?

That is a big NO, NO if your service from the pole is 100A.

[Bill Douglas]

Originally Posted by VINMAN

That is NOT a ground screw! It is the middle phase! ( with a bad connection..)

Umm, thanks, Really all I meant to point out was the screw has had some current through it and it shouldn't. Sincerest apologies.

[Shaun @ Tru6]

Originally Posted by 70SATMan

Yep. Could be corrosion between the plates has created high resistance causing the potential to arc across the lower resistance conductor to the plate which is through the screw.

Shaun, is this box only acting as your main disconnect which then routes three phase to another panel???? If so, does your other panel have another three phase main breaker??

If this is your set up I'd think about having that box fully replaced with a switch blade disconnect with in line phase fuses instead of just replacing that breaker.

There is more corrosion in there than should be...

The entire box is for upstairs (me) and downstairs, the auto parts runner. We of course have separate breakers and meters.

The way it seems to work is the line from the telephone pole goes to this box outside and then this goes to my inside breakers.

I wouldn't mind asking NSTAR to turn off the e- to put anything in, whether a new breaker or a new unit as you describe. If I can install a new breaker while hot, great. NSTAR has a 2 week wait and I need this next week, so there's that.

The face of the building, and this box, is against the constant pattern of weather. it's annoying actually. wind blows against it non-stop which means every single bit of trash 1/2 mile in front ends up on my step. The box cover is a poor excuse for protection with many of the screws not in so that weather will always seep into the cavity.

[RWebb]

you need to pony up and get an electrician over there - money cost will be less if you avoid burning down the building or going to the ER

[VINMAN]

Originally Posted by Bill Douglas

Umm, thanks, Really all I meant to point out was the screw has had some current through it and it shouldn't. Sincerest apologies.

Bill, I apologize. I wasn't yelling at you. I'm just really touchy with this stuff.

Like I said, I'm an electrician ( been doing it for 30 yrs) , but I have a staunch policy against giving people directions on electrical issues. Even If I give the right advice, it may be misinterpreted or they may be an underlying problem that nobody sees. You cant tell just by looking at a picture or by someone's explanation. If a friends house burns down or even worse they get seriously hurt, because of something I said to do, even if I am correct, I'd be devastated.
On my firefighting end of it, I see it happen all the time.

[Bill Douglas]

No need to apologize. All we collectively want to do is give Shaun the info to (a) not get fried (b) not spend money on an electrician if he can safely swap out bits and tighten up screws. It's good to have a REAL electrician around!

[john70t]

It would be wise to get the owner's written consent before making changes.
Just sayin'.

Store off-site.

[dyount]

I'd call an electrician without question. Fine to do a little investigation to eliminate possibles etc. I don't get why this is even a 3ph service with it being used as single phase.
Anyway, the breakers aren't that old but must be getting soft with weather etc.... and I'd rather they be more sensitive rather than never trip (search Federal Pacific electrical panel fire)
My guesses as an electrical inspector btw are: replace breakers after checking amp draw each leg of the sub panel being served. You may have a bad neutral conductor just as easily as a bad breaker. IF the breaker does need replaced it should be easy to get and not all that expensive. DO NOT do it live! Do NOT pull the meter yourself either.

[dyount]

I'm sure pelican won't mind but why not post this instead on Mikeholt.com , They've got some folks there that I turn to for questions. My strong point code wise is not electrical but rather building/fire panic

[GWN7]

Call an electrician. As stated the middle feed is arcing. Look at the metal filings on top of the breakers from the short. The same is happing to the metal bar in the back the screw mounts to. It might be welded to the screw or will break when you try to undo it. If you try to do it hot you might end up with no power at all if things at the back of the box are screwed up.

When you get it repaired build a wood box to cover the breaker box from the weather. This will stop any direct snow/water/debris from coming in to contact with it.

[carambola]

fine, do you really know what you want to do?