Popped breaker question...

[CarCrazyRDM]

I'll try and make this short and sweet but if you need more info ask away. For the record I am not an electrician, obviously, but have done enough wiring to be comfortable.

Recently finished all electrical in my garage. Up and running for 2 - 3 months. I plug in my circular saw last weekend and as soon as I pull the trigger on the saw the breaker for that circuit pops (20 amp GFCI breaker, 12ga wire). I reset the breaker it trips again as soon as I pull the saw trigger. Keep in mind I am not cutting with the saw yet, literally just spinning the blade over (ie no load) and it trips immediately. I believe at this point I plugged the saw into another outlet on the same circuit and the same thing happened again. Except now the breaker won't reset... it immediately trips as soon as I try and reset the breaker.

At the time this occurred there was no other load on the circuit. The entire circuit consists of maybe 8 outlets and two lights on the front of my garage. The lights were not on at the time and the only thing plugged in other than my saw was my garage door opener. Anyway, I plug the saw into another circuit and all is well. I was in the middle of a project and didn't have time to mess with the electrical issue at the time.

My question is, based on what I described above is there anywhere in particular someone with more experience would recommend starting? My plan is the start at the receptacle where I first had the saw plugged in but didn't know if it might actually be a breaker issue based on what happened.

Thanks in advance for any advice. I hope to resolve this issue this weekend.

 

[wyliesdiesels]

u said u plugged saw into another outlet that worked. Did that outlet have GFCI protection on it? If so then your GFCI breaker is bad. If not then u may have a problem in the saw where current could be leaking.

What brand and model panel do u have? Is the breaker the same brand and model?

 

[CarCrazyRDM]

The first alternative outlet I plugged the saw into was on the same circuit, and it popped again. But to be clear neither of these outlets were GFCI themselves... the breaker for this circuit is a GFCI breaker.

The second alternative outlet I tried was on another circuit and yes, it was also a GFCI protected (again, the breaker, not the outlet itself). And on this circuit the saw ran fine for several hours of use. The saw is relatively new and is a Bosch saw, I suspect no issues with it.

And I have an Eaton panel and all Eaton breakers. I don't remember the specific panel model but I can get it if necessary this evening.

 

[wyliesdiesels]

Try replacing the breaker and see if the issue goes away.

Yes let us know what brand and model breaker it is.

 

[LXCam]

I'm with Wylie that most likely the breaker is junk. But before you going buying another breaker I suggest you try a little experiment to rule out a potential wiring issue. Move the good breaker over onto the circuit that giving you a problem and try it exactly the same way you did when it was tripping. If it does not trip then absolutely its the breaker. If it does trip I'd start looking for a fault between the ground and neutral.

 

[wyliesdiesels]

I'm with Wylie that most likely the breaker is junk. But before you going buying another breaker I suggest you try a little experiment to rule out a potential wiring issue. Move the good breaker over onto the circuit that giving you a problem and try it exactly the same way you did when it was tripping. If it does not trip then absolutely its the breaker. If it does trip I'd start looking for a fault between the ground and neutral.

Since breaker only trips when saw is on i doubt its an issue between the neutral and ground wires of the circuit.

 

[EOC_Jason]

I had the same issue...

Eaton BR panel / breakers...
Levitron GFCI receptacle in the garage...

My Makita circular saw runs fine on the original GFCI circuit in the garage. After I installed another circuit of plugs in the garage w/GFCI, it initially would trip the circuit instantly as soon as you pull the trigger...

I tried replacing the GFCI plug thinking maybe it was faulty. Nope, same thing happened.

The "ah ha" moment came after various trouble shooting. Basically it boiled down to after you reset the GFCI, run something large that won't trip it (On one circuit I have my two garage door openers, on another I have a bench grinder for example).

After doing that I could run my makita just fine. I guess the circuitry in the GFCI plug is a little touchy initially and a circular saw draws a LOT of current on start-up and just makes it trip even though it shouldn't.

 

[LXCam]

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Since breaker only trips when saw is on i doubt its an issue between the neutral and ground wires of the circuit.

Until there is current draw on the circuit its not going to trip. Granted it's a bit of a stretch but within the realm of possibilities.

 

[CarCrazyRDM]

Thanks for the input guys. As a couple of you suggested, my first plan of action was going to be swapping circuit breakers and see if the problem repeats itself (on either of the swapped circuits).

And thanks for the heads up on what you experienced EOC_Jason. That sounds very weird but I will definitely keep it in mind if I find similar results. I'll post up with what I find either way.

 

[wyliesdiesels]

I had the same issue...

Eaton BR panel / breakers...
Levitron GFCI receptacle in the garage...

My Makita circular saw runs fine on the original GFCI circuit in the garage. After I installed another circuit of plugs in the garage w/GFCI, it initially would trip the circuit instantly as soon as you pull the trigger...

I tried replacing the GFCI plug thinking maybe it was faulty. Nope, same thing happened.

The "ah ha" moment came after various trouble shooting. Basically it boiled down to after you reset the GFCI, run something large that won't trip it (On one circuit I have my two garage door openers, on another I have a bench grinder for example).

After doing that I could run my makita just fine. I guess the circuitry in the GFCI plug is a little touchy initially and a circular saw draws a LOT of current on start-up and just makes it trip even though it shouldn't.

Contrary to popular misconception, GFCIs do not have any overcurrent protective circuitry in them. They dont care about how much current is running through them just that its equal between hot and neutral.

 

[CarCrazyRDM]

Well I got home a little early from work today and decided I wanted to at least swap two breakers around real quick and see the results. Now I'm more confused, lol. Actually I guess I am "happy" because everything seems to be working fine now. But I still would like some input because I want to ensure there isn't some condition that is potentially a fire hazard or otherwise.

So I swapped another 20 amp GFCI breaker from another circuit out with the original one in question. The original problem-breaker now would reset and not immediately trip, nor trip if I plugged in and ran my saw. And the "new" breaker that I plugged into the originally problematic circuit also did not immediately trip nor did it seem to have any issues when I ran my saw, turned on the front lights, or operated the garage door. So currently all is seemingly functioning fine and all I did was interchange two breakers.

Any ideas? Is it possible I didn't have one of the wires fully seated in the terminal of the breaker or something? I looked at the terminals and the tips of the wires in the problematic circuit and saw nothing that gave me any concern.

Thanks for any ideas or suggestions as to things to check if you think there might be an issue somewhere in my circuit.

 

[LXCam]

You might have just had a poor connection. There's no reason to keep looking.

 

[EOC_Jason]

Contrary to popular misconception, GFCIs do not have any overcurrent protective circuitry in them. They dont care about how much current is running through them just that its equal between hot and neutral.

I wasn't really meaning over-current... Just that the large amp draw somehow gave it a false positive until some other devices were used on the circuit. Like it has to calibrate itself or something... I know they are probably pretty simple devices, but I've been able to re-create tripping my GFCI if I cut the power to it, then use the saw first thing... Weird I know... I've never taken apart a GFCI to see what makes them tick, I don't really care that much... lol

 

[wyliesdiesels]

Well I got home a little early from work today and decided I wanted to at least swap two breakers around real quick and see the results. Now I'm more confused, lol. Actually I guess I am "happy" because everything seems to be working fine now. But I still would like some input because I want to ensure there isn't some condition that is potentially a fire hazard or otherwise.

So I swapped another 20 amp GFCI breaker from another circuit out with the original one in question. The original problem-breaker now would reset and not immediately trip, nor trip if I plugged in and ran my saw. And the "new" breaker that I plugged into the originally problematic circuit also did not immediately trip nor did it seem to have any issues when I ran my saw, turned on the front lights, or operated the garage door. So currently all is seemingly functioning fine and all I did was interchange two breakers.

Any ideas? Is it possible I didn't have one of the wires fully seated in the terminal of the breaker or something? I looked at the terminals and the tips of the wires in the problematic circuit and saw nothing that gave me any concern.

Thanks for any ideas or suggestions as to things to check if you think there might be an issue somewhere in my circuit.

what model breakers do you have?

I wasn't really meaning over-current... Just that the large amp draw somehow gave it a false positive until some other devices were used on the circuit. Like it has to calibrate itself or something... I know they are probably pretty simple devices, but I've been able to re-create tripping my GFCI if I cut the power to it, then use the saw first thing... Weird I know... I've never taken apart a GFCI to see what makes them tick, I don't really care that much... lol

Gave a false positive of what? Large amp draw is different than imbalance between hot and neutral which is what GFCIs measure. GFCIs dont do calibrating. And most newer GFCIs trip upon loss of power which is a safety feature. Again has NOTHING to do with current draw.

You are assuming that GFCIs operate a certain way based on lack of understanding.

The only thing they care about is the current flowing on hot and neutral and whether its balanced/equal..

 

[R.Anderson]

what model breakers do you have?



Gave a false positive of what? Large amp draw is different than imbalance between hot and neutral which is what GFCIs measure. GFCIs dont do calibrating. And most newer GFCIs trip upon loss of power which is a safety feature. Again has NOTHING to do with current draw.

You are assuming that GFCIs operate a certain way based on lack of understanding.

The only thing they care about is the current flowing on hot and neutral and whether its balanced/equal..

You sure the newer GFCI recepticals are designed to trip when there is a power loss? I know there are GFCI plugs for equipment such as pressure washers that trip when unplugged or a power failure. I never seen a GFCI receptical made to do this tho, if so this could potentionally lead to problems with lift and drainage pumps, hydronic pumps, and gas water heaters. I know I would not like to have to run around after a storm and reset GFCIs to keep critical systems powered.

 

[wyliesdiesels]

You sure the newer GFCI recepticals are designed to trip when there is a power loss? I know there are GFCI plugs for equipment such as pressure washers that trip when unplugged or a power failure. I never seen a GFCI receptical made to do this tho, if so this could potentionally lead to problems with lift and drainage pumps, hydronic pumps, and gas water heaters. I know I would not like to have to run around after a storm and reset GFCIs to keep critical systems powered.

yes.

And the gas water heaters around here dont plug into an outlet. Which water heaters are you referring to?

 

[R.Anderson]

I wasn't really meaning over-current... Just that the large amp draw somehow gave it a false positive until some other devices were used on the circuit. Like it has to calibrate itself or something... I know they are probably pretty simple devices, but I've been able to re-create tripping my GFCI if I cut the power to it, then use the saw first thing... Weird I know... I've never taken apart a GFCI to see what makes them tick, I don't really care that much... lol

It is no calabration and all balance like Wyliediesel said. Some GFCIs can be too sensitive or faulty and trip to small fluctuations. With the saw you maybe catching it at the right time on the 60hz frequency to create such a fluctuation to trip it. So with that I highly doubt it has anything with Denergizing and energizing the GFCI unless the saw was plugged in and turned on.

 

[EOC_Jason]

It is no calabration and all balance like Wyliediesel said. Some GFCIs can be too sensitive or faulty and trip to small fluctuations. With the saw you maybe catching it at the right time on the 60hz frequency to create such a fluctuation to trip it. So with that I highly doubt it has anything with Denergizing and energizing the GFCI unless the saw was plugged in and turned on.

Like I said, I have no idea why, but I can re-create it on-demand... If I throw the breaker on that circuit (or reset the GFCI), then turn it back on. If the saw is the first thing I use it will trip 100% of the time immediately. The saw will just start to spin for fraction of a second before tripping... I can reset it and it will continue to trip if I try to use my saw. But if I operate something else first (like I mentioned before my garage door or bench grinder), then my saw is fine and I can cut wood all afternoon with no issues.

Now, with that said... Maybe my saw is borderline or something. I got it new in the box Makita 5007F.... 15A saw... If I had another similar saw to try I would, then I could determine if it was the receptacles or the saw...

 

[CarCrazyRDM]

Like I said, I have no idea why, but I can re-create it on-demand... If I throw the breaker on that circuit (or reset the GFCI), then turn it back on. If the saw is the first thing I use it will trip 100% of the time immediately. The saw will just start to spin for fraction of a second before tripping... I can reset it and it will continue to trip if I try to use my saw. But if I operate something else first (like I mentioned before my garage door or bench grinder), then my saw is fine and I can cut wood all afternoon with no issues.

Now, with that said... Maybe my saw is borderline or something. I got it new in the box Makita 5007F.... 15A saw... If I had another similar saw to try I would, then I could determine if it was the receptacles or the saw...

That is still very strange to me. But glad you got it figured out... or at least how to get around it.

 

[Milton Shaw]

I am wonering if instead of GCFI it was an ArcFault breaker and it was catching the arcing of the brushes in the saw motor as and arc fault. I don't have any in my house to check to see if that could happen.. I know GCFI'S will trip and even the slightest difference in current, don't know about ArcFaults but from other posts on this site some of them give a lot of unjustified trips.

 

[CarCrazyRDM]

I am wonering if instead of GCFI it was an ArcFault breaker and it was catching the arcing of the brushes in the saw motor as and arc fault. I don't have any in my house to check to see if that could happen.. I know GCFI'S will trip and even the slightest difference in current, don't know about ArcFaults but from other posts on this site some of them give a lot of unjustified trips.

Both breakers I have been referring to are Type BR Eaton GFTCB120CS models. They are ground fault breakers.

 

[R.Anderson]

yes.

And the gas water heaters around here dont plug into an outlet. Which water heaters are you referring to?

What model/make? Tried finding em with no luck. I could use one in my shop for the circuit feeding my saws.


Electricians around here place an outlet near for hot water heaters so plumbers can install without the need for a electrician it also serves as a means of disconnect for em. Do they need to, no but it is done this way often. Even electrical water heaters are sometimes power via recepical.

Water heaters that are plumbed into your house types.