Inspection prior to resetting a Breaker

[Natfuelbilll]

Picture this:

You receive a service call, something is out.

Initial observation reveals a tripped breaker that supplies the load that is out.

No one knows why it tripped. Was it a overload? Was it a phase to ground or phase to phase short circuit?

What methods do you use to identify why the breaker tripped?

My question applies to different voltages 120, 240, 277, 480 and up.

Thanks,
Bill

 

[eiplanner]

Initially you should reset the breaker and see if it trips again. But, resetting should only be done 1 time. After that, you must research the problem.

 

[eiplanner]

You reset the breaker 1 time. If it trips again, you must research the problem.

 

[khixxx]

I guess it depends on the application on how to approach this. Personally I would not reset anything with out looking into it. nothing like a ball of fire in your face.

 

[360Youth]

To quote a world famous owl, "The world may never know." If everything checks out, at best you can replace the breaker, hoping it was just getting weak. Outside of waiting around and monitoring the circuit readings, hoping the annomily happens again, what else can you do? I went on a service call this week for a generator and ATS we sold, but a separate EC and builder installed. For some reason the AC breaker would trip when power was restored from generator to utility. I met the EC out there and we checked and compared voltage, amperage, frequency. I finally noticed at one point that it was actually about 3 seconds after re-transfer that the breaker tripped, not at the same instance. We checked amperage and it was 70 amps on a 30 amp breaker. It was like the unit was going into start-up mode when it shouldn't and was lasting too long, so the breaker would not hold. Thankfully, it happened again when the EC pulled the disconnect to check his connections and restored power, so it took our generator out of the equation. You won't be the first, or the last, electrician to scatch his head over a tripped breaker. I've seen lighting strikes trip breakers, equipment surges, or just a plain old weak breaker out of the box. Keep an eye on it though, because I've also seen a siding nail clip a wire that would take months or years to break down a wire to the tripping point. Those instances will increase quickly once they start. At least the breaker is doing it job at that point.

 

[celtic]

Disconnect load, check line for fault.

Fault, investigate further.
No fault, turn it on.

Check load for "issues".

NOTE: Load has not been reconnected until issues and faults are cleared.

 

[480sparky]

I would initially start asking a lot of questions.

What has everyone doing at the time? What was plugged in / what did you plug in? What was turned on / what did you turn on? Did someone do something when it tripped, or did you just notice it was off? What all went off when it tripped? Has this happed before? When? How was it resolved then? Did anyone hear/see/smell anything? I can hook up a long-term power monitor to try to catch it again... do you want to pay for that?

I've seen lighting strikes trip breakers

I get at least two calls the morning after a good storm.

 

[davidr43229]

You reset the breaker 1 time. If it trips again, you must research the problem

This is a direct violation of OSHA 1910.334 and would not sugget to anyone.
I am in full agreement with Celtic, you need to trouble shoot the circuit to determine what made that breaker actuate in the 1st place. It was either an overload or fault (short). A simple check with your ohm meter on each hot leg on the load side of the breaker can determine this. You must correct the situation before energizing the circuit.
Just my $.02

 

[Pierre C Belarge]

One of the most common actions taken when an electrician or EC goes to a site where a CB has tripped is to first just try to reset it. That is as has been pointed out definitely the wrong action.

First, ask as many questions as you can (remember most people do not tell the whole truth thinking it will cost them more money, or they do not even know what to answer). Then a visual check of the circuit (as much as you can discern from the conversation or seeing what is deenergized). Some times you eyes are the best tool to help in these situations. Then take out your tester and check the affected feeder or branch circuit wiring.


The problem with what I just stated as the operating procedure is two fold.
1. it is more time consuming than just throwing the CB.
2. more time consuming leads to greater cost of which most consumers do not want to pay.

 

[360Youth]

I hope I did not misspeak and come across as just restting the breaker and letting it go. You must definitely investigate to see what you can find. But how many times have we gone to service calls where the answer is never found for a tripped breaker. Everything must be checked, of course. Check voltage, amperage, voltage under load, etc. I had a call on house we finished a little less than a year ago. The kit gfi circuit was tripping. I eventually found, in a shallow box I had to install after a change order, that ground and neutral were touching and the gfi breaking was tripping. I also agree with the asking of questions and finding out if there have been any recent changes. I wired a house about 7 years ago, a large custom home. Because of the size I was extra careful not to overload circuits, because they could add up very quick. We got called back for a foyer circuit tripping.
I put my meter on and was reading 17 amps on a 15 amp circuit. I couldn't figure it out until I found the 16' christmas tree with circulating pump and lights. I asked one of our guys to unplug the tree and and amperage dropped to less than 10.

 

[hillbilly]

Speaking of tripped breakers.

If it's a standard breaker that's tripped, I investigate before I try to reset.

What do you do first when it's a GFCI or AFCI breaker that's tripped?

I usually try to reset the breaker first, and if it won't reset, I investigate.

How many have found a actual problem on the circuit that caused a GFCI or AFCI to trip?

steve

 

[masterelect1]

What methods do you use to identify why the breaker tripped?

My question applies to different voltages 120, 240, 277, 480 and up.

Thanks,
Bill

First order of business should be a visual inspection. Sometimes a simple "look around" will yield a clue as to the problem. If nothing abnormal, then:

120v.-Check the directory;I've found that many tripped brkrs. are bathroom or kitchen circuits.
I always look for the "dumbest" thing first. Example- bathroom- curling iron heating up while hair dryer is being used. Kitchen- toaster oven/toaster/ microwave being used in some combination at the same time.

208 and up, bring out the meters !!

 

[Electron_Sam78]

When I was in the Air Force we once had a 7.2kv fused cut-out that blew at a pole mounted x-frmr. Come to find out, after hours of headache and a couple more blown cut-outs it was a 20a, 120V branch circuit that had a refrigerator with a bad compressor that was causing the overload. The funny thing was that the 20a CB that the refer was on wasn't tripping or the 100a main breaker. We left that job scratching our heads. Never seen anything like that before.

 

[cowboyjwc]

I'm in a mood today so my answer is reset the breaker and look for the burn mark, that's where you'll find your problem : )

 

[zog]

"This is a direct violation of OSHA 1910.334 "

I was reading through the first few posts in horror until I read this, thank you David.

For those who just reset breakers go to www.osha.gov and do a search for circuit +breaker+fatality, let me know when you are sick of reading about the same thing causing unecessary loss of life over and over.

 

[brian john]

It really depends upon the situation, voltage and rating of the CB:

1. Ask questions, try to determine if this was an overload or instantaneous trip.
2. Look for obvious problems visual is 75% of problem solving, maybe 80% could be closer to 85% to 90%, it is definitely not a 100%.
3. Disconnect load and verify all connected loads are off the line, and megger the conductors.
4. If the conductors megger OK, check all loads for shorts using megger.
5. If the end user needs power ASAP and you can safely restore the tripped CB to service after completing 1, 2 and 3 do so and restore individual loads as they are cleared of any possible fault issues.

 

[360Youth]

How many have found a actual problem on the circuit that caused a GFCI or AFCI to trip?

steve

My only faults have been ground and neutral touching.

 

[Psychojohn]

I hope I did not misspeak and come across as just restting the breaker and letting it go. You must definitely investigate to see what you can find. But how many times have we gone to service calls where the answer is never found for a tripped breaker. Everything must be checked, of course. Check voltage, amperage, voltage under load, etc. I had a call on house we finished a little less than a year ago. The kit gfi circuit was tripping. I eventually found, in a shallow box I had to install after a change order, that ground and neutral were touching and the gfi breaking was tripping. I also agree with the asking of questions and finding out if there have been any recent changes. I wired a house about 7 years ago, a large custom home. Because of the size I was extra careful not to overload circuits, because they could add up very quick. We got called back for a foyer circuit tripping.
I put my meter on and was reading 17 amps on a 15 amp circuit. I couldn't figure it out until I found the 16' christmas tree with circulating pump and lights. I asked one of our guys to unplug the tree and and amperage dropped to less than 10.

A circulating pump on a christmas tree, why?

 

[brian john]

My only faults have been

Does you wife agree with this statement?

 

[George Stolz]

I'm in a mood today so my answer is reset the breaker and look for the burn mark, that's where you'll find your problem : )

I don't know, I probably had a left hand before resetting the breaker, so I imagine that wasn't the problem.