Hi
Recently, when i use my dryer, the main breaker becomes extremely hot and trips, while the dedicated breaker for the dryer remains cool and does not trip.
so, first I thought I have bad breaker (100 amp) and I changed it with a new one. BTW, I also checked how much amp the dryer pulls from the main and that is about 30. I do not have any other high energy consuming devices in my house so it is extremely unlikely that I am pulling even close to 100amp.
Replacing the main breaaker dis not solve the issue so i realized that the dryer plug had arced and burnt. I changed both the outlet and the dryer cable today, however the breaker still gets hot and trips (only when dryer is on). So I have 2 questions:
1- why does the dedicated dryer breaker never trips while the main breaker, which is new, does trip?
2- what is the next step you recommend? Should I change the heating coils inside the dryer?
thank you

 

Welcome to the forums.

You said the electric dryer is tripping the main.
Do you have an electric water heater or electric range ?
They should cause the same issue.

Since you replaced the main breaker and it still gets hot.... that would indicate a loose connection where it connects to the buss bars in the panel.

 

It gets a little expensive just guessing and replacing parts.

How did you check the amp draw? The dryer shouldn't be pulling more than about 22 to 23 amps.

I think PJ just put his finger on your problem.

 

Is this an old/new issue? If a new issue, was any electrical work done in the house? The dryer breaker is not tripping because the dryer breaker amperage is not being exceeded (dryer on) or the dryer breaker has a failure to open on over current. I am assuming you have a AC current meter since you checked the dryer draw and know how to be safe around exposed AC. Your response will help me in providing further assistance.

 

@pjmax:
I do not have an electric range or water heater.
The tripping/heating also occured with the old braker which was fine before. I may have a loose connection to bus in the new one that I have installed myself but I am sure that the older breaker was correctly installed in place because had that not been true, the heating and tripping should have occurred before as well. This is just started recently.
If we assume that the connection to the bus is loose, should bot it lead to heating and tripping all the time? Why does it only cause a problem when the dryer is on?

 

@beelzebob
this is a new issue, we have been in this house for 2 years and this problem started 3 months ago.
I had not done any electrical work around the house before this issue started!

 

Is the dryer the only 240 volt load breaker in the electrical panel? If yes, then the current draw on each of the 2 input wires at the dryer and the 2 input wires into the 100A main should be the same with all 120 vac breakers off. Can you perform this check?

 

Are there other times when you are not using the dryer but y ou are using enough other things to draw 30 amps or more total?

 

I would say that odds are that the 30 amp breaker is bad and will not trip.

On top of that there is probably a problem in the dryer.
It is pulling too many amps and that is why the receptacle overheated and failed.

 

"BTW, I also checked how much amp the dryer pulls from the main and that is about 30." What instrument did you use to make this measurement?

 

You must answer a few basic questions if you want help.

From post #3

What kind of panel do you have? From the limited information you have provided I believe you may have an older aluminum bus panel and that when the 100 amp main breaker overheated it damaged the aluminum bus. Therefore, the new main breaker is not able to make good contact with the bus. My speculation is an extension of PJ's comment in post #2.

 

Hi, sorry for delayed response.
I have an old breaker box and checked the bus to make sure it has not been damaged. Upon my visual inspection, it seems perfectly fine. I can not see any erosion or burn or damage.
I checked the amp using a clamp meter.
I suspect the 30 amp breaker of the dryer is faulty because it never trips even though the 100 amp main breaker does trdoes should I replace it just for safety? It is unlikely to solve my problem though.
How can I check if the problem is the dryer itself, especially with the heating element?

 

If it was me I would change the breaker!!!

What is the make and model of your dryer?

 

You say you checked the amps being drawn, but never mentioned how many amps the dryer was drawing. You will not get many constructive comments when withholding the vital information.

 

@CasualJoe
The dryer was drawing about 25 amps

 

You need to respond to questions in a post when you are looking for help. Revisit post # 7

 

A 25 amp load will not trip the 30 amp breaker nor will it trip the 100 amp main breaker.

I still think PJ hit on the problem in post #2:

 

It sounds like the thermal component of the breaker is tripping, not the magnetic on overload.

 

Hi All.
Upon further investigation, I realized that the breaker was a bit loose. I noticed a loud buzzing from it. I fixed it in place and there is no longer any heating or tripping!

 

See, PJmax was right!