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

16K views 110 replies 18 participants last post by  s0lidgr0und 
#1 ·
I'm not an electrician. i figured I'd get that out there. I know some stuff about it, I have run it throuout my house. I don't know code, the mathematics behind it, etc.

That being said, here is the problem I'm having.

In the last couple months my 150 amp main breaker has been tripping. It started out with a slight burning smell in the basement. I sniffed and traced it to my circuit breaker panel. One of the the two legs that come into the panel box gets very hot. I couldn't figure out anything that could be wrong at first. I made sure the lugs were tightened down.

One day I noticed that it only seemed to happen when my dryer is running. So one day I touched the black leg going into the breaker box and it was cold. I walked over to my dryer and turned it on. Within the 15 seconds it took me to walk back over to the circuit panel, the one leg was already warm to the touch. Within about 10 minutes it was too hot to even touch. Then as had been happening, the 150 amp main breaker tripped.

Does this sound like anything that any of you have heard of before? In my experience the smaller breaker will trip first if there's a problem. I spoke to my local Wolberg and they told me there's a thermal trip in the main, so the heat is what is making it trip in the forst place. They told me that replacing the 150 amp breaker was an option, but I fail to see how that would keep the incoming leg from getting so hot.

Oh, and this circuit isn't one that I installed or otherwise altered in the three years that I've lived in this house.

Thank for any help that any of you can give me.

Bill
 
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#7 ·
This ain't good. Turn the dryer breaker off. Confirm with a tester the dryer breaker is ACTUALLY the dryer breaker. Pull dryer receptacle out of the wall and check connections. Replacing the breaker won't fix this problem. Post back.

Andy
I traced the line from the 30 amp breaker to the dryer receptacle and it's the only thing on that particular circuit. I will confirm that all connections are tight later on tonight, but I believe I already have checked them all.
 
#3 ·
You've got a bad connection between the main breaker and one of the hot buses or a loose connection on one of the incoming hot wires to the main. If you have an outside disconnect, you can kill power to the incoming hot wires and check for tightness. If there is no outside disconnect, then pulling the meter is your only option (NOT a DIY project). If the breaker/bus connection is bad, you will probably need a new panel. My guess would be an old Westinghouse or Zinsco panel.

Call an electrician.
 
#8 ·
You've got a bad connection between the main breaker and one of the hot buses or a loose connection on one of the incoming hot wires to the main. If you have an outside disconnect, you can kill power to the incoming hot wires and check for tightness. If there is no outside disconnect, then pulling the meter is your only option (NOT a DIY project). If the breaker/bus connection is bad, you will probably need a new panel. My guess would be an old Westinghouse or Zinsco panel.

Call an electrician.
I was sort of hoping to avoid this, but it's looking like I may have to.

I wonder if it does it when the oven is on "broil". If so, then Househelper is correct. There is a small possibility it is a POCO problem to.
I actually thought of this and it doesn't affect it at all. When the oven in on broil and/or I have the flat-top stove on nothing changes in the panel box that I can see. Of course those two breakers are on the other leg going into the panel.
 
#5 · (Edited)
Sounds like a bad breaker to me, the wire will get warm, the heat is just expanding so to say... after you replace the breaker, smash the old one open and you will see what is happening...

as a side note, may want to fix this before it ruins the bus...and that needs replacing also...

What brand main breaker is it? Push-o-matics a.k.a. Bulldog & Federal Pacific are notorious for this...
 
#61 ·
Sounds like a bad breaker to me, the wire will get warm, the heat is just expanding so to say... after you replace the breaker, smash the old one open and you will see what is happening...

as a side note, may want to fix this before it ruins the bus...and that needs replacing also...

What brand main breaker is it? Push-o-matics a.k.a. Bulldog & Federal Pacific are notorious for this...
Chris, I suspect you are right and I screwed Fido in post # 2. Still wonder if another 240V load affects the main. That is my biggest question here.

Andy
You've got a loose connection in the main wires at that burned lug. You will need to remove the main wires, cut away the damaged portion and re-install. If there is not a disconnect at the meter, you will need an electrician to pull the meter and repair this. Do not use any high load appliances (dryer, range) until this is fixed.
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.
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.
IMHO, these posts are "right on the mark"! Also & from what I've seen of the photos, you may not have to replace your distribution board (breaker box).

I have seen this problem at least 100 times on various projects etc. The cause is usually a bad connection & nothing to do with anything else.

Buy the new circuit breaker, get the cable fixed (not by sanding it but by cutting away the damaged section) & I guarantee your problems will be solved.
 
#9 · (Edited)
Actually, no. An electric oven (I'm making a big assumption that it is 240V like the DRYER) on broil should produce the same effect as the 240V dryer IF the problem is a loose main lug. 240V power utilizes both legs. Make sense? If no other 240V loads mimic the effect the dryer has then I think I am gonna have to think on this.:huh:

Nap time for Andy....CARRY ON!
 
#12 ·
I have been toying with this thing all night. I traced it back to the dryer - it's the only item on the circuit. The wires into the back of the dryer are all connected well and tight, the receptacle itself is all wired well and tight, the plug is pressed all the way into the receptacle, and the 30 amp breaker is wired well and tight. The breaker is pressed all the way into the circuit panel.

Here is the whole panel.


Here is the top lugs of the two legs going into the box.


Here is a closeup with of the leg that gets very hot.


When I got downstairs the whole line from the dryer to the circuit panel was cold. I started up the dryer and let it run for five minutes. Nothing from the dryer to the panel was even warm. That section of the leg that goes into the panel was hot. I went outside and nothing from the meter head into the house is even remotely warm. So I can only assume that the problem exists right at or near the lug.

I'm not terribly familiar with the anatomy of a circuit panel, so I don't know what to do, which leads me to believe I'm going to have to call in a professional.

I guess the one thing I'm looking for (other than a clearcut answer) is if it would be worth it to replace the 150 amp main breaker in the box before calling a professional? My father in law is a maintenance guy if 30+ years and has experience installing these types of panels and said he could replace the breaker, but at $110 for just this one breaker I wonder if I should just skip over the DIY repair and let an electrician kill me with his bill. Sure, his bill will be lower than the cost to repair a burned down house, I realize. I have just never owned a home before and it's getting tiresome having people like this (plumbers, electricians, furnace repair, etc) come in here, do what seems to be next to nothing, and then drop a $500 invoice in my hand.
 
#60 ·
I'm not terribly familiar with the anatomy of a circuit panel, so I don't know what to do, which leads me to believe I'm going to have to call in a professional.

I guess the one thing I'm looking for (other than a clearcut answer) is if it would be worth it to replace the 150 amp main breaker in the box before calling a professional? My father in law is a maintenance guy if 30+ years and has experience installing these types of panels and said he could replace the breaker, but at $110 for just this one breaker I wonder if I should just skip over the DIY repair and let an electrician kill me with his bill. Sure, his bill will be lower than the cost to repair a burned down house, I realize. I have just never owned a home before and it's getting tiresome having people like this (plumbers, electricians, furnace repair, etc) come in here, do what seems to be next to nothing, and then drop a $500 invoice in my hand.
What seems to be "next to nothing" is basically an experienced tradesman or woman who has spent quite a bit of time and energy, and sometimes money, tapping into a skillset they posess, and achieved for the purpose of earning a living.
 
#13 ·
Don't like the look of that wire one damned bit. And it doesn't happen when you put another high amperage load on it from a 240V breaker? Like puttin the oven on broil?

If it doesn't, then I am officially stumped. That leg shouldn't care if the dryer is running or if the oven is running. A load is a load. What am I missing here?

If it doesn't occur on any other load, then I WOULD NOT run that dryer. It's laudromat time if it was my house. Do you own a meter. I would pull the dryer recp. and the wires from underneath the breaker (turning off breaker of course and checking voltage with the meter, 'cause I ain't trusting the dryer breaker anymore either!!!) and check for continuity between each of the hot legs and the ground.

As far as invoices go...I resemble that remark.:whistling2: :yes:

Andy
 
#21 ·
Don't like the look of that wire one damned bit. And it doesn't happen when you put another high amperage load on it from a 240V breaker? Like puttin the oven on broil?
Son of a beach. It is doing it with the oven's broiler on.

Has there been any other construction including maybe somebody putting up a fence etc between you and the transformer in the last few months?
None. The line exits the top of the box, goes into the meter, to the top of my service, and then to the pole.

I would not change out the panel yet. The best advice I can give you is to keep the dryer off and schedule an appointment with a licensed master electrician,as soon as you can to come and analyze the problem. He will have to come out and fix the problem and HONOR his work, so now responsibility will be on him. We can speculate all day long what the problem may be, but assumption is the mother of all ______ ups. You cannot put a price on the safety of your home and family. There could be a problem on the powercompanies side as well in the meter or elsewhere.
Point taken, thank you.

are my eyes deceiving me or is that a strand of the neutral wire hanging beside the hot lug?? if so it may be arcing with high current demand from the dryer.
It's a tinsle-like piece of plastic of some sort. I pulled it off.
 
#15 ·
I would not change out the panel yet. The best advice I can give you is to keep the dryer off and schedule an appointment with a licensed master electrician,as soon as you can to come and analyze the problem. He will have to come out and fix the problem and HONOR his work, so now responsibility will be on him. We can speculate all day long what the problem may be, but assumption is the mother of all ______ ups. You cannot put a price on the safety of your home and family. There could be a problem on the powercompanies side as well in the meter or elsewhere.
 
#16 ·
You've got a loose connection in the main wires at that burned lug. You will need to remove the main wires, cut away the damaged portion and re-install. If there is not a disconnect at the meter, you will need an electrician to pull the meter and repair this. Do not use any high load appliances (dryer, range) until this is fixed.
 
#23 · (Edited)
Solidground, my already cold ridden sinuses were going to make my whole head explode:laughing: :yes: if you didn't say the oven caused the problem also. Replace the breaker yourself...or have an electrician do it. Up to you. Post back on the results! The photos were excellent and I'm sure we would all love to see photos of the panel with the breaker removed, if it is not to much trouble.

Andy

Edit to add...there is still a small possibility that the panel will have to be replaced. Also...if there is no outside disconnect, then you will HAVE to have an electrician do it.
 
#25 ·
"Son of a beach. It is doing it with the oven's broiler on.]"

Try and limit your electricity usage until you get some help. I dont know exactly what circuits you have on, or how long this problem has been going on or what has been added. (subpanels, heating systems etc) I wouldnt use the range or dryer thats for sure. You may have a loose connection somewhere or maybe your 2 legs arent balanced and more current is flowing through your right leg. You may need a service upgrade. It could be a number of things Again these are just possible scenarios that a licensed electrician will (should) be able to figure out. Dont hire an electrician under the table, make sure you get documentation, or a billing statement of work done, so if he says it is safe, he has to honor that. Best of luck,
Rich
 
#27 ·
This question is for the pros.

Is the anti - oxident compound supposed to prevent this type of connection failure ? Or does it look like the end was in poor shape or damaged putting it in ?

While you may get away with replacing the breaker - it looks the the wire is also going to have to be replaced too. I don't see how you can avoid calling an electrician. (Soon)
 
#28 ·
Anti-oxidant is just that. The problem with AL is that it expands and contract MUCH more than copper does with temp. fluctuations. I have personally retightened lugs that I installed initially with a torque wrench and was a bit dismayed at the difference a few months make.

There is a teenie weenie chance this is a POCO problem, but it is certainly sounding like a breaker.

Andy
 
#29 · (Edited)
It is a compound that is used to prevent oxidation of aluminum wiring. You can tell when this is happening cause the wire will begin to turn green like the statue of liberty. However a corroding wire can cause connection failures and breakage. In the picture it appears his wiring is not corroding. It seems to be a heatbuildup that exceeds the rating of the awg. But yeah aluminum conductors do expand and contrast (creepage) which could loosen connections.
 
#32 ·
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?:whistling2:
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.
 
#33 · (Edited)
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.
 
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