Unique problem - House main trips, but nothing else - only when dryer is on

Andy in ATL

Did you buy them between '05 and 06? These aren't actually Sq. D. breakers being recalled. They were counterfeits.

On another note...can you push my app. to your forum thru?

s0lidgr0und

Oh. Good point. That whole electrical system was put in around 2000. Maybe I should learn to read more than just the first three lines of anything.

Sure thing. Give me two seconds to log in.

AllanJ

I thought aluminum produces only white corrosion as opposed to green. If there was green corrosion, that was from a nearby copper conductor or copper mounting bracket.

All the oxidation has to be cleaned off before a correct repair will have been made. While untorquing and retorquing down the set screw usually cleans the set screw and the lug threads and the small solid conductor going into an individual breaker, trying to squish down the large stranded aluminum feed wire and crunch out the corrosion that way probably won't work in the situation at hand.

Can you tell if the burned lug is part of the panel versus part of a replaceable main breaker assembly?

An electrician would probably want to replace the main breaker assembly immediately rather than sand the lug clean only to find out that the breaker itself is bad.

Also the electrician would want to snip off the burned end of the incoming cable, but the cable is too short to stretch so he will have to unweave the strands and sand each of them clean instead.

>>> laundromat time
It's winter and you probably need some moisture in the air. If you let clothes dry on a rack in the house for the time being, you can save on electricity via the compromised cable and lug and breaker in the panel needed to run a humidifier.

s0lidgr0und

The lug appears to be riveted to the 150 amp main breaker, but I can't be sure.

HouseHelper

The white lettering on SqD breakers is a relatively new thing. The absence of the white just means they are older.

I still say it's a loose connection at the damaged lug.

AllanJ

Another joint that could have oxidized within and perhaps warped due to the many times the overheating has taken place by now. Only this time you cannot disassemble and clean it. Another reason the electrician would want to summarily replace the breaker.

This being a DIY forum, is the only reason why this is not a DIY situation the inability to cut the power without pulling the meter? Would you really rather try to clean the exposed lug connection properly yourself and see whether that works before calling an electrician?

chris75

By looking at the pictures you obviously have some arching going on, so the lug is not torqued, or there is an internal problem with the breaker... either way, get it fixed ASAP...

If the breaker feels hot to the touch I would lean towards a bad breaker, but you can usually hear the arching inside of the breaker...

AllanJ

Gives me an idea.

Turn the dryer breaker off. Turn the dryer on. Turn the basement lights off. Now you can go over tot he panel, turn the dryer breaker on, and see if you can see as well as hear arcing (maybe in the lug) just when the problem is about to start.

Also turn it off quickly before it really heats up.

tribe_fan

I guess I don't get all the discussion of where the failure is. I'm not a pro, but spent many years in the electronics field. ( DC Circuits)

There is evidence that the failure is the connection at the breaker, and it damaged the wire as well as probably the breaker. ( not sure if it can be cleaned)

If it were my house I would want the wire and breaker replaced, or you will be replacing the Panel shortly after a fire.

I have seen some bolt type connectors that could extend the wire (splice), but I have no idea if it is legal.

I would like to hear the theory as how this would be a POCO Problem ? ( not being a smart a$$ - just like to know).

I would not be doing this type of troubleshooting - a flash could easily blind you. I would NOT run any high current appliance until you get it fixed.

If you dont have a disconnect - calling a pro is the only option, as I don't think the POCO will remove a meter for a homeowner.

s0lidgr0und

I had been leaning in that direction before I came to this forum, but I'm sort of leaning toward calling an electrician. My father-in-law has pulled meter heads at his own houses to do work on his box, so I believe I could trust him to do it at mine.

elkangorito

To me it's an "open & shut" case of a Hot Join.

In such cases with small switchgear assemblies, the faulty equipment must be replaced & not repaired (not cost effective). The damaged cable must be removed as it will be "work hardened" by the heating etc. Work hardened metal is brittle & can easily break. If there is not enough spare length in the cable to do this, the cable must be replaced. An alternative is to discontinue the use of the damaged core & install a single double insulated core in its place (if this is permissible by the local code etc).

__________________
Switchboard design engineer & Licensed Electrician (Australia).

Stubbie

I can't add much to what all has been said here. I've been following the thread and I believe househelper and chris have pretty much nailed what this problem is. Just looking at the pictures I notice quite a bit of exposed wire at the strip point vs. the other red ungrounded service entrance conductor at the connection to the breaker lug. This really doesn't mean much other than it could be there has never been enough of the bare conductor under the compression screw of the lug. Over time this has become an issue with overheating. I also notice the compression screw on the hot point is turned in about 3 more threads than the others which also doesn't mean a lot but could mean it hasn't ever been a good connection from the git go. My humble opinion is to replace the breaker to solve any issues with it and if I have to pull the meter I would replace the SEU cable as well.

__________________
" One nice thing about the NEC articles ... you have lots of choices"

Stubbie

s0lidgr0und

Electricians on the board - give me a ballpark invoice for something like this. Replacing the main 150 amp breaker ($107 part) and pulling a new line from the meter to the breaker box ~10 feet.

AllanJ

More care is needed here since the feed wire is aluminum.

Only if the power company must oversee work all the way to the main breaker, which I think is a rare code requirement if it existed anywhere. But more common although not universal is a requirement that only a licensed electrician service the main breaker and upstream.

I would not touch that lug with the power on.

Hardly anyone would opt for cleaning the connection, favoring replacing everything in one fell swoop instead, given that otherwise several ons and offs would be needed.

skymaster

Solid; YES get a professional in there ASAP. You may try this also; I dont know if your power company is responsible only on to the meter or up to the panel so, I would call them fist thing Monday morning, since you are a homeowner who is "scared" :} dont tell them you know anything, play the game.:}:}:}:} If you catch em on a good day they may just find and fix it for ya for free even if they dont they will surely point ya in the right direction.
Worth the dime in my book
Jack