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

http://forums.pelicanparts.com/uploa...1390245758.jpg

+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.

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

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.

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.

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.

Should I get a larger breaker?

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...

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

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

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

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.

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

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.

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!

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

Store off-site.

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.

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

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.

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

Yes that is a problem the middle phase is arcing. It's time to call building maintenance or if you own the building an electrician. Also I think you had the meter set up wrong not sure as I don't own either of those units. But the meter was on dc mv and was reading a -10 amps or dc mv on the third phase in the first set of pictures. Again I think it's time to get an electrician

Given this set up then to code your inside panel should have the same 100A main breaker to apply power to your individual breakers. Your bad box is just acting like a disconnect which needs to be fused but, not necessarily a breaker. That would be up to your local code.

Tough call here.

I've been here since 2005 and never had a rent increase, even paying well under market. I take care of my floor, patched holes in the roof, installed a hot water heater from scratch (my plumbing is significantly better than the guys who built the building), and the property manager and I are very friendly. When he needed the "forest" cut down out back so the pest control guys could get into the building next to us, I did for him. Was actually a lot of fun. Sawzalls aren't just for cutting cars apart. He never gets a call saying something is broken. I want to keep it this way.

So if I can do this myself, I will. My biggest concern is NSTAR's 2 week timeframe for shutting the e- off.

what if you give the landlord a call out of concern that his bldg might burn down?

you could float the idea of you "taking a look at it" and then either let him pay for an electrician or offer to pay part of it and not that you appreciate him not raising your rent all these years

So if I read the meter right you have 63 milli Amps DC through 2 phases and -10 through the other.

why not set it to the 30 amp range and the meter to AC volts? That way 30A = 300mV. Think it is higher than 30 amps?

Two week wait? What is there only one guy who works for them? It's a 5 minute job to pull a meter.

Line up a electrician. Then call the non emergency number for the fire dept. Tell them the power went out in your building and you traced it to the shutoff. When you reset it there was sparks and ask if they can send someone to check it out as your worried the building will burn down. They will send a truck (no lights or sirens) and they will go "yep it's been arcing" and they will call the E company to pull the meter. Your electrician fixes the problem and meter is replaced. :)

I had some fun today. I wasn't able to fix this when I needed to and ended up just running a HD extension cord from the guys downstairs the few times I needed to. Last few days, one of the three branches was shorting out intermittently, and of course my office & internet are on that circuit. Power would go off and then come back on sometimes instantly, sometimes in a few minutes. So today was the day to tackle the job of replacing the main breaker outside, ol' sparky.

I couldn't the meter off to break the circuit so I just pulled the breaker off the panel. So far so good. Labeled the lines and then did a 1:1 conversion to the new breaker. The blades that insert into breaker were very corroded so I cleaned then as best I could with a little wire brush. Pressed the new breaker in and all is fine.

Thank you everyone for all the help, made a big difference.

Here's what the old breaker looks like. Tons of corrosion.

http://forums.pelicanparts.com/uploa...1401665903.jpg

http://forums.pelicanparts.com/uploa...1401665930.jpg

Yes, corrosion is resistance, and you also have resistance where the screw is making the connection to the breaker. The heat is not from draw, it is from resistance. Carbon is resistance as well.

Don't screw with it unless the meter is pulled.

That's one ugly main.

I ended up replacing the breaker with the meter in place, I couldn't get it off. Did you know you can wire brush the box blades and not die!

I love having uninterrupted electricity again. First World living is pretty good! :)

You do realize the blades were hot while you were brushing them... and hot as in absolutely no breaker between you and the nearest transformer, kill you voltage/amperage. If you couldn't get the meter out at least were you wearing heavy duty electrical rubberized gloves?

yes, that was the fun part! I was standing on a palette, had heavy rubber gloves on, wrapped the plastic handle-metal bristle brush with EPDM and had at it. You could see stuff burning away in the bristles. pretty cool.

Definitely an adventure.

Thanks for the coffee nose shot on that one.... Sounds like something I'd do. Although a headline of "electrical inspector found dead because of not following code" wouldn't do my family any good collecting my insurance policy.

Glad it all worked out well.

'Darwin Strikes Again' was my first thought.

I've done the same with 600 volts. Twice. But not on purpose.

Go buy some lotto tickets because you are one lucky son of a gun.

I have worked around electricity pretty much my whole adult life and done some pretty sketchy things but nothing remotely as crazy as that.

That was some "kill you dead" current & voltage you were playing with right there... as in Bzzz... "we are gathered here today to pay our respects to..."

Mind over matter, right Shaun?
If you don't mind, it don't matter. Try not to kill yourself would ya?

I have learned long ago that I am way too amusing for God to let me off this planet any time soon. Driving to OH now to pick up a tub and back on Sunday. Greater chance of something in a Jersey hotel on the way back killing me than this breaker.

Blue colony diner in CT rocks!