(800) 853-2651
SHOP NOW

100 amp main breaker tripping ?

M

Mike M

Well-known Member
I have had or 100 amp main breaker trip 2 times in about 3 or 4 months ? It shouldn't of had near as much load going on at these times as in the hot summer with the AC and pool pump running.

Can these just go bad inside of thierselves and cause this problem.

I have never had any of the other breakers ever trip that I can remember either. I'd think if there was an electrical problem something else smaller rated would trip first.
 
Yes breakers can go bad. They trip because they heat up when there is a problem and that makes them trip.

So the thing to do is MAKE SURE there is no problems (like rodent chewed wires) or other shorts or too much demand. If everything is good replace the breaker.

Your best bet is going to have an electrician take a look.

Rick
 
YES it is "possible" a breaker can go bad but many Ive had go bad will NOT allow themselves to reset back (i.e. they stay open) when such mechanical related failures occur.

As far as the heavy loads such as AC etc in the summer, if a continuous overload occurs the a thermal magnetic breraker will trip out via its thermal function versus its magnetic.

As far as nuisance tripping when theres no long term overload condition, it may be due to an intermitten short circuit somewhere causing the main to trip out via its magnetic function (short term high current fault). ASSUMING ITS A THERMAL MAGNETIC BREAKER?????

If possible Id hang a clamp on ammeter on the main feeders and turn on the most used appliances and monitor the load over a term. If its well below the 100 amps which Id expect, Id start looking for evidence of shorting burning and arcing especially in say electric ranges and hot water heaters.

Id also check the tightness of all breaker connections and all Neutral connections in the panel and then take a look at the plugs and connections in the range and washer dryer and hot water heater.

SUMMARY Use an ammeter to monitor the mains,,,,,,,,turn on and off and plug and unplug major appliances (stove, dryer, hot water heater etc) and see the amp changes,,,,,,,,,,check the hot water heater connections and look for burning or arcing,,,,,,,check all Neutral and hot connections in the panel and torque as required

Id more expect an intermittent short in an appliance (stove, hot water heater, dryer etc) then the main going bad or else a loose arcing connection in a Neutral or some hot connection.

John T
 
It would be hard to say if have an underlying problem but breakers do wear out. I had one at my house do that so I just changed it out and never had anymore problems.
 
I agree with old tanker, breakers can go bad. I would how ever first change your main breaker mind you i have extras in shop and would do it myself. if different or new breaker also trips then you gotta start looking further and figure out why? just my 2 cents. Rocko.
 
I checked the connections at this and some other breakers. I couldn't really get it any tighter.

It is a Murry panel in our house I don't know what type of a breaker it is ?

If an appliance was at fault wouldn't it pop the breaker for it instead ?

We do have an electric hot water heater,stove and dryer. Yesterday when it popped wife and son said they opened up the garage door to leave and then it wouldn't shut. Stove and dryer were to be off. First time it happened I think we were just setting around watching TV. I don't think the stove or dryer were running ? Hot water heater could of been at any time though. Might be good to peek at it and check for loose connections.
 
I've seen many bad ones. They can only trip a certain amount of times and the bi-metallic heat-sensitive spring gets weaker and weaker. Then the trip bar "trips" under a lower then rated load. And even if it's never tripped from overload - like any spring - these can get tired.

Some places take them apart and recalibrate - but obviously it's not worth it unless it's an obsolete breaker not available anymore.
 
John T gave you the correct answer - Tightness - Had the same thing. Feel the two lead in wires into the box - warn or hot the leads are NOT tight into the box. Breaker will trip at any unknown time. Beeeee sure to used an electricians screw driver.
 
For sure, check that hot water heater, an element may be limed up and theres an intermittent short..Sometimes a hot water heater has a fuzed or non fuzed disconnect safety switch and a short might NOT blow a fuze but trip the main instead

John T
 
The most important thing you can do is pay attention to what's on and what's not when the breaker trips. Listen for sizzling noises. Feel for hot breakers.

I would be worried because if the main breaker is legitimately tripping, and you just keep resetting it, you're going to eventually burn the house down.

This is not something to mess with. If you can't figure it out for yourself right quick, call a professional. Having a professional come in for a few hours is going to be a lot cheaper than rebuilding the house and replacing everything you own.
 
i agree with old tanker call a eletrician it is your home and oviously others live there also you dont want to put others in danger or yourself trying to save a few dollars good luck.
RICK
 
Murray breakers are probably the most common and usually interchange with Cutler Hammer BR, Crouse-Hinds, Bryant, Siemens, Connecticut Electric, GTE-Slyvania, Gould, GE, Challenger . . . and maybe more.
 
Had a simlair problem once with an almost new house. The main breaker tripped. Noticed it would not trip if the air conditioner was off. The problem was lead in wires not tight enough as others here have mentioned.
 
i was told in school its not the best practice to feel the plugs,with out turning breaker off. people have been fried doing this. use one of those thermometers. also smell is a good indication of things going south.
 
I find it kind of funny when people say you MUST call an electrician. Maybe yeah, and maybe no. Everybody differs when it comes to skills.

Hopefully the poster has some level of self-awareness of his own capabilities.

That being said, there is nothing high-tech about checking amp-load on your system if you've got the proper tools. Like a clamp-over inductive amp-meter? You can buy a new one for $30.

Granted that some people should not risk working on their own electic panel. Same can be said for people driving cars, operating tractors and owning guns. Should nobody dare work on their own tractor now?

I'm wondering how any of this relates to him "burning his house down?" Nobody told him to stick a penny in his fuse-box. Seems there are lot of worry-warts here. I'm sure many on these forums have the brains and skills to check a service panel. Those that don't hopefully already know their limitations. If not - I doubt they are going to heed the scary warnings in these posts.
 
My dad was always the electric guru of the family. Since his stroke a few years back he still knows alot of things ,but can't talk so it makes any sense. He has an old amprobe meter that you can clamp on. I'll go borrow it and hang it on the main lead in and see what draw there is.

I would totally expect if I called an electrician given how intermitant this has been they would find nothing ,but an expensive bill.
 
Mike, I installed a 200 amp panel box years ago. Did several installs before ours. Had the main breaker trip for no apparent reason. Heard frying sound coming from the area around the main. Pulled the Meter, removed the main , low and behold corrosion on the bar the main bolts up to. Cleaned off the corrosion, used a dab of dialectic re-installed main, checked tightness of each and every circuit breaker wire,including the main breaker copper wire. re-installed the meter, called the Co Op.had meter re-tagged. Been 15 years now. No problem. Panel box is in the living room closet. No water supply close that would carry moisture to the bus bar in the panel box. 1st one I have ever seen. Information on this subject is correct. Best bet, get an electrician to look at the problem. LOU.
 
Hey there Mike, Im NOT any trained or professional "electrician" (longggggg retired distribution design engineer) however I wouldnt bet the farm on your statement:

"I would totally expect if I called an electrician given how intermitant this has been they would find nothing ,but an expensive bill"

While that may be true, a trained experienced professional may be able to determine the cause EVEN IF ITS HAPPENS INTERMITTENTLY as they know where and what to look for such as evidence of arcing,,,,,,,,loose connections,,,,, faulty breakers perhaps EVEN WHERE A NON TRAINED LAY PERSON MAY NOT FIND THE CAUSE.

I enjoy helping whenever I can here on electrical related topics and when such a question is asked many come out of the woodwork with well intentioned suggestions (some right some wrong some professional some lay opinions) as they all seem willing to help just like most tractor loving folk tend to do and God Bless em all for that. There are likely trained professional electricians here, an engineer or two or three, untrained lay persons who have wired their own homes or shops and perhaps others with little training or experience BUT THEY ALL TRY TO HELP and I sure wouldnt fault anyone who in good faith and conscience advises seeking trained professional advice when the cost couldnt possibly exceed the risk of a persons life when it comes to electrical and fire safety.

Its your home and your money so the decision is yours so hope you find the problem either alone or with professional help and it could be as simple as a bad breaker or a loose connection or an appliance or an intermittent short

God Bless and best wishes to you and all the good folks here

John T
 
I had a problem with mine where the main wire to the box came through the wall. It was not sealed properly and was allowing mositure to get in. We resealed it and the problem went away. My SISTER-LAW is a electrican and found the problem.
 
Thanks for all the good ideas.

Now next question. Is there any way this could be caused by our electric supplier ? I have heard that they may of cut back the cycles ? This is Ohio Edison if it matters ? maybe someone knows of them doing something goofy ?

Our electric service is VERY !! prone to going off.
First time it happened didn't even give it a second thought and called it in as a power outage. We left and went to vist the folks and when we came back had a note on the door that all was to be fine up to our house. Went down and checked and sure enough main was tripped. That was several months ago. Didn't even give that a second thought.Just thought it was a fluke ,but now a second time something somewhere is not right.
 
I'll add that hiring someone that goes by the title "electrician" does not guarantee quality of work. Many US states have no licensing requirements although they recommend it. So, in many areas anybody can do electrical work for hire with no proof of expertise and/or experience.

I kind of got a laugh over this statement from a New York Dept. of Labor document -

"The fact that most of the residential electrical work isn't very technically difficult, means that the field is flooded by non-licensed handymen doing the work. This is another factor that contributes to the lower profit margins in the residential electrical sector"

Here are the regs in a few states I'm familiar with:

NY Licensing
No state licensing of contractors or journeymen. Some local government entities license electrical contractors. Separate or additional permits may be required to perform the electrical work.

PA Licensing
The Commonwealth of Pennsylvania has no requirements related to the registration, certification or licensure of contractors (or their employees) that are engaged in the construction industry.

Florida Licensing
All electrical contractors must be registered with the state unless they are certified. Registration permits the contractor to engage in contracting only in a particular area or municipality. No state level examination is required for registration. Licenses may be issued by registration or certification. Registration: The applicant has taken and passed a local competency examination and can practice only within that locale.

OHIO Licensing
No localities require any restriction other than registration from practicing electrical contracting in that locality.
 
All depends on your specific breaker. Many are rated to work fine with 50 cycles, 60 cycles, and NO cycles with DC current (like some Square D type QO breakers).

You might want to try a new breaker and see it works better - assuming you've found nothing else wrong.
 
I had the same problem with a foreclosed house I bought in Michigan. Roof leaked for years - right into the main panel. Several breakers were tripping now and then for no other reason but the corrosion. Had odd-ball Wadsworth breakers that were not easy to find. I finally bought some used breakers, cleaned it all up and it's now fine. Fixing the roof was a bit more difficult.
 
Good question but I doubt if the problem is the utility isnt producing 60 cycle power which I would question and even if so I dont think the breaker (but not having its specs no warranty)would trip UNLESS there was maybe a drastic voltage or frequency shift.

Just do a good visual inspection (arcs, burns, loose connections) and check torques and connections and use an ammeter

Keep us posted

John T
 
You need to do a "Fall Of Potential" test on your breaker that is tripping. Known as FOP, the test goes as follows.....take a digital multimeter, set mV (millivolts) read across the breaker on the SAME PHASE. normally your meter will read 0 volts on this, but set to mV, you will have a reading. compare both phases, if either result in more than .0XXXX volts, change your main. Main breakers do go bad as you are finding out.
 
I'm wondering how any of this relates to him "burning his house down?" Nobody told him to stick a penny in his fuse-box. Seems there are lot of worry-warts here. I'm sure many on these forums have the brains and skills to check a service panel. Those that don't hopefully already know their limitations. If not - I doubt they are going to heed the scary warnings in these posts.
Click to expand...

We are talking about a 100 Amp circuit breaker that is tripping here. If that breaker is not bad, SOMETHING in the house is drawing 100+ Amps, and its MUCH SMALLER circuit breaker is not working...

Yes, many on this forum have the smarts to check a service panel, but THEY ARE NOT THERE. They can't see, hear, or smell warning signs that the OP may be ignoring. We can only go by the OP's interpretation of what we ask, and by the OP's interpretation of what he observes.
 
(quoted from post at 09:33:18 01/13/12) I'll add that hiring someone that goes by the title "electrician" does not guarantee quality of work.
Click to expand...

So what then? You have no idea how to fix it yourself, but you can't trust a professional.

What do you do? Just keep resetting the breaker, I guess...
 
I will have to agree and disagree with you John,we don't know what his load is(how close to 100A)and if it has ran close long enough the breaker will weaken and start tripping at lesser loads.We learned that a long time ago on grain dryer setups because you can't go on the motor plate numbers because a 50AFLA motor may pull 40-45A or it can be pulling 65-70A depending on static pressures.
 
Not so much as not trusting them as much as from years in the equipment repair business of when there is an intermitant problem it NEVER acts up for the repairman ! I saw this way too many times when working at the car dealer too.
 
If it was mine (and I know it's not) . . . I'd turn every major appliance on in the house and then check both legs with a clamp-on inductive amp-meter. If nothing scary is found - I'd replace the breaker and see if things improve. You can probably find a new breaker for $25-$30 depending on what specific breaker you have. Being Murray brand does not mean a lot since they make a dozen different breakers. Look for the actual letter-code e.g. "MP", "MQ", "BL", etc. The panel will specify which breaker types it's compatible with.

I wouldn't work it hot. I'd pull the meter out to kill the power to the house and then replace the breaker.

Back to your original question - some breakers just go bad over time. The trip is activated by a thin bi-metal strip. Especially if in a cold damp area, or if the breaker has been overloaded several times and auto-tripped.
 
So true, one of Murphys Laws maybe??? As I posted below despite that a trained experienced professional electrician might still be able to determine the cause even if its not tripping when hes there. Hopefully just a bad breaker or an intermittent short in a major appliance or a simple bad or loose connection is all it is

Hey, a new main isnt all that expensive nor is it hard to stick an ammeter on there!!

Best wishes, let us know what you find

John T
 
Remove the main breaker from the panel. My guess is you will discover the breaker is bad. The place where the main connects to the buss bars is likely to be burned. Or where the wires connect to the main are arking.

Turn your power off by pulling your meter, which means you'll have to cut the tag. Unless you have an electrician do this for you, you'll have some explaining when the electric company discovers a cut tag.

Before you do that, go to Harbor freight and buy an Infra-red therometer. Turn everything on in the house, stove, water heater, furnace, lights, washer, dryer. Measure the temp of the main breaker where the main wires connect. You may have to remove some breakers to measure the temp where the main breaker connects to the buss bars. High temps will trip a breaker too.

I would also measure the current in both power wires. It may be possible you need to balance the loads so, the amp on your 110v loads are equal. Get an ammprobe. You can get a cheap one at Harbor Freight too.

My guess is you have a bad breaker or bad connections to the main, which means you will need a new 100a breaker.

DON'T KEEP RESETTING THE MAIN. IT'S TRYING TO TELL YOU SOMETHING AND YOU ARE NOT LISTENING. FIND THE PROBLEM OR GET PROFESSIONAL HELP.

George
 
Some older panels are not rated or approved for ALUMINUM wire. Proper panel will have al/cu stamped somewhere usually on terminal. Use of ALUMINUM in older panel of the wrong type will cause corrosion and heat, voltage drop and tripping. Dave, retired electrician with 5 licenses years ago.
 
You must log in or register to reply here.

Similar threads

J
Electric question
2
Replies
22
Views
1K
JMOR
J
S
Circuit breaker issues
2
Replies
26
Views
6K
buickanddeere
B
J
CHOOSING WIRE SIZE AND WELDING
2 3
Replies
44
Views
3K
DoubleO7
DoubleO7
B
S7 200 amp Inverter Welder review $99
Replies
17
Views
3K
bc
B
R
Slow hydraulic pressure buildup
Replies
5
Views
900
Tx Jim
Tx Jim
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top