Square-D Breakers

[Gene45]

Does anyone have experience with Square D breakers?

I put a Square D panel in the garage/shop, and these breakers seem odd compared to any others I have used. Sometimes they will trip for apparently no reason.

For example If I turn on the shop vac, the breaker Might trip without so much as a twitch from the vacuum. When I reset it I can run the vacuum and radial arm at the same time on the same line. Then it will run fine for weeks.

And it is not just one breaker, they all seem to do it.

[sparky from winnipeg]

Square D are the top of the line in my book, seems like you may just have a defective breaker and it needs to be changed out.

[Pete in Milton]

That's the only kind I will install in my home.They are top of the line Feranti Packard are an economy breaker and a lot of electricians like Siemens, I think for availability but I'm not sure, I can't think of any reason they might act like this, Are they secure on the buss and are the connections tight? if you don't know what you are doing stay out of the box and call an electrician in to look at it.
Bets Regards
Pete

[Todd]

Seems strange that more than just one of the breakers are doing that. We usually always use Sq. D and when i redue my own panel that is what i am going with. It sounds like the breakers are older and maybe weak or if they are new you may have bad ones which is strange that more than one would be defective. The other thing is maybe there is just too much load for that breaker and you need a T-slot receptacle with #12 wire and a 20 amp breaker.

[Gene45]

The other thing is maybe there is just too much load for that breaker and you need a T-slot receptacle with #12 wire and a 20 amp breaker.

Its strange that the breaker will trip with just a vacuum and then carry the vacuum plus the radial arm one minute later, so it can't be a simple overload.

[Ed in Leaside]

And it is not just one breaker, they all seem to do it.

Is it just the vac which trips the breakers?

[Mike in Orangeville]

Is it just the vac which trips the breakers?

Good question! I didn't twig on that until you asked it. That's the $20,000 question, right there.

[Gene45]

Is it just the vac which trips the breakers?

No, the last time it was the air compressor. It tripped when I was not in the shop. When I came back, I tried to turn on the radial arm (12 amp motor)and the breaker was off.

I flipped it on and the air compressor started, I immediately turned on the saw and went ahead with sawing.

So in this case the 20 amp breaker tripped with a 1 1/2 HP compressor alone, then carried the compressor plus the 2 HP saw at the same time with no problem.

That's what I find so confusing. Sometime it will trip like a GFI with a fault and then carry more than a full load with no problem. And then not be a problem for weeks.

That circuit originally had a 15 amp breaker and I switched it to a 20 amp and still have the same problem.

I also have another 15 amp breaker on a table saw that does the same thing, which is why I asked about Square-D. I have had FPE and Sylvania before (in other buildings) with no such issues.

[billh]

Breakers operate by both a magnetic trip and a thermal trip. The thermal for the longer-term overloads and the magnetic for the surges caused by fast overloads such as too big a motor starting or dead shorts.

Is there a chance you have too long a run of #14 wire from your breaker panel to the motors? The high in-rush current would cause too much of a voltage drop and the motor won't start as fast possibly causing the breaker to trip.

AFAIK, all Square-D Q0 breakers are rated for HACR use which is something like Heating, AirConditioning, Refrigeration and tolerate motor startups. Are your breakers the Q0 variety or a different line?

If the problem is manifesting itself on the same circuit only, then I think I might start checking the circuit from the panel to every outlet looking for any signs of overheating, arcing, or unusual connections. By unusual connections, I am referring to perhaps other devices on the circuit that you are unaware of such that if they are running the startup of the shop tool causes an overload.


I also am a Square D fan and have had no trouble with them.

billh

[Mike in London]

Hi Gene

Billh has made some good suggestions.

I think your problem lies with starting current or in rush current on the motors of your equipment. Depending on the Full Load Current of your various motors, your breakers may be sized incorrectly.

Refer to this thread for better understanding.

http://forum.canadianwoodworking.com...ad.php?t=18004

[Gene45]

shorts.

Is there a chance you have too long a run of #14 wire from your breaker panel to the motors? The high in-rush current would cause too much of a voltage drop and the motor won't start as fast possibly causing the breaker to trip.

AFAIK, all Square-D Q0 breakers are rated for HACR use which is something like Heating, AirConditioning, Refrigeration and tolerate motor startups. Are your breakers the Q0 variety or a different line?


billh

There are not long runs of #14 wire dowstream of the breakers but there is about 75 feet of 40 amp circuit between the house and shop. (40 amp FPE breaker is in the house.)

Where is the "Q0"designation marked? I don't know the answer to that question. I can look in the box, but where am I looking?

[billh]

I looked at mine with them as installed and don't see any Q0 designation so it must be on the "hidden" part of the breaker. The Q0 breakers are pretty well the standard Square-D breaker but apparently they do have another line which I understand is cheaper but I may be wrong. It could be your panel will tell you the type of breaker it supports.

Your 75' run of presumably #8 shouldn't be a problem unless it is carrying a lot of other loads as well.

Have you measured your line voltage? I wonder if the problem happens when you have a significant dip?

billh

[J.P. Rap]

The real electricians have given you some good advice but I'll offer the following...This is just a stab in the dark because I have been in a similar situation.
Perhaps it's more than one problem.

For example If I turn on the shop vac, the breaker Might trip without so much as a twitch from the vacuum. When I reset it I can run the vacuum and radial arm at the same time on the same line. Then it will run fine for weeks.

And it is not just one breaker, they all seem to do it.

Have you checked out the vac? A loose wire in the vac, cord or plug could be shorting out and trips the breaker "without so much as a twitch from the vacuum". It could work fine for weeks or months then fail because the cord or loose wire is in just the right position to short. BTDT

No, the last time it was the air compressor. It tripped when I was not in the shop. When I came back, I tried to turn on the radial arm (12 amp motor)and the breaker was off.

I flipped it on and the air compressor started, I immediately turned on the saw and went ahead with sawing.

So in this case the 20 amp breaker tripped with a 1 1/2 HP compressor alone, then carried the compressor plus the 2 HP saw at the same time with no problem.

Does your compressor leak at all? Has it ever given you similar problems?
Again I had a similar situation. My compressor would start fine at lower pressure but if I turned it on when it was near the high limit, the motor didn't have enough umph to start and would trip the breaker. It would even sometimes trip the breaker while running when it got close to the upper limit. It also leaked a bit so I had to unplug it when not in use so it didn't trip the breaker in my absence.
If your compressor came on when you weren't in the shop, it must be leaking down. Could it have overloaded the breaker as it reached it's upper limit. When you were in the shop (could have been days later) the compressor hadn't been running in that time so it leaked down quite a bit. It would draw less power on start up because of the lower pressure. Once it gets going it isn't drawing all that start up power so you can run your RAS at the same time even though they are running very close to the breakers limit.
I repaired my problem by increasing the pulley ration on my compressor.

Like I said, I only mention it because I had a very similar situation so it's definitely a possibility.
Hope you get it figured out.

[sparky from winnipeg]

I noticed you mentioned that you have 20a breakers on 14/2 circuits this is not a good idea if you have just 15a recepts as it has the potential to overheat the wire and start a fire. Square D only makes two types of breakers for canada the push in ones are QO and the bolt in ones are QOB I am 99.9% sure you have the QO's.

[Phred]

Do you have mice or squirrels in your shop. There might be some wire damage or temporary shorting or grounding by those vermin.

[Gene45]

AFAIK, all Square-D Q0 breakers are rated for HACR use which is something like Heating, AirConditioning, Refrigeration and tolerate motor startups. Are your breakers the Q0 variety or a different line?


billh

I have a 15 amp which I took out months ago. It has the bar code sticker on it with the designation "Q0115".

It isa "snap-in" type.

[Gene45]

In reply to J.P. I'm not as elegant as you for formatting various quotes but:

Quote "Have you checked out the vac? A loose wire in the vac, cord or plug could be shorting out and trips the breaker "without so much as a twitch from the vacuum". It could work fine for weeks or months then fail because the cord or loose wire is in just the right position to short."


If the vac trips the breaker, I can leave it turned on when I reset it and it works fine without even moving the switch again. Its the same on more thatn one breaker and more than one tool.


Quote: "Does your compressor leak at all? Has it ever given you similar problems?
Again I had a similar situation. My compressor would start fine at lower pressure but if I turned it on when it was near the high limit, the motor didn't have enough umph to start and would trip the breaker."

The compressor leaks depending on what I left hooked up, so it may start when I am not there. It has an "unloader" valve so it never starts under full load. As I said once before, the breaker did trip with just the compressor, then held with the compressor and radial arm.

If it did the same thing every time, I might be able to find it.

[Mike in London]

In reply to J.P. I'm not as elegant as you for formatting various quotes but:

Quote "Have you checked out the vac? A loose wire in the vac, cord or plug could be shorting out and trips the breaker "without so much as a twitch from the vacuum". It could work fine for weeks or months then fail because the cord or loose wire is in just the right position to short."


If the vac trips the breaker, I can leave it turned on when I reset it and it works fine without even moving the switch again. Its the same on more thatn one breaker and more than one tool.


Quote: "Does your compressor leak at all? Has it ever given you similar problems?
Again I had a similar situation. My compressor would start fine at lower pressure but if I turned it on when it was near the high limit, the motor didn't have enough umph to start and would trip the breaker."

The compressor leaks depending on what I left hooked up, so it may start when I am not there. It has an "unloader" valve so it never starts under full load. As I said once before, the breaker did trip with just the compressor, then held with the compressor and radial arm.

If it did the same thing every time, I might be able to find it.

Hi Gene

I still think your breakers are sized incorrectly, the 80% loading rule doesn't apply to motors. Breakers for motors are sized at 250% of the Full Load Ampereage of the motor. Wire is sized at 125% of the FLA. If your breakers were sized correctly you wouldn't be experiencing this random tripping.

Here's an example, let's say you have a dual voltage motor and the motor has an FLA of 12A on 240V. You say cool, 12A is 80% of 15A, so I'll use a 15A 2 pole breaker and #14 wire. Wrong!!!!!!

Sec 26 I believe(? sorry I don't have my codebook in front of me) of the CEC covers motors. Sizing of breakers for motors is not to exceed 250% of the FLA of the motor, wire size is 125% for a continous duty motor but can be smaller for a periodic duty motor.

Therefore breakers size;

2.5 x 12 = 30A

You use a 2 pole 30A breaker.

Wire size

1.25 x 12 = 15A

You use #14 wire but I'd bump to #12 since it's right on the limit.

Some find these rules strange because they differ from the residential rules but they're right in the codebook. This would most certainly eliminate your random tripping. The higher breaker size allows for the higher starting current. If you're concerned about damaging a motor, each motor will have it's own thermal overload protection, normally the red reset button found on the end of the motor and in the case of a magnetic starter, overloads in the starter.

[Gene45]

Hi Gene

I still think your breakers are sized incorrectly, the 80% loading rule doesn't apply to motors. Breakers for motors are sized at 250% of the Full Load Ampereage of the motor. Wire is sized at 125% of the FLA. If your breakers were sized correctly you wouldn't be experiencing this random tripping.

Here's an example, let's say you have a dual voltage motor and the motor has an FLA of 12A on 240V. You say cool, 12A is 80% of 15A, so I'll use a 15A 2 pole breaker and #14 wire. Wrong!!!!!!

Sec 26 I believe(? sorry I don't have my codebook in front of me) of the CEC covers motors. Sizing of breakers for motors is not to exceed 250% of the FLA of the motor, wire size is 125% for a continous duty motor but can be smaller for a periodic duty motor.

Therefore breakers size;

2.5 x 12 = 30A

You use a 2 pole 30A breaker.

Wire size

1.25 x 12 = 15A

.

Based on this, I bet everyone's breakers are sized incorrectly, and manufacturers are selling stuff that isn't legal. For example, my radial arm saw is rated at 12 amp 110 volt. It came with a standard 110 volt 3 wire 15 amp plug. Likewise the shop vac and air compressor. All would not qualify to run on a single 15 amp breaker but they came with 15 amp plugs. Why is that?

I never had this problem with Sylvania or FPE breakers. If the breakers are really undersized, why would it trip with one 12 amp motor starting (sometimes), but not when the same 12 amp motor is starting and another 12 amp motor is already running.

I'd like to now go check on those vac's that claim to be 6.5 HP.

BTW I once had a household vacuum guy tell me thy had the most powerful machine available at 2 1/4 HP. When I checked the spec plate it was only 6 amps. When I pointed out to him that it was really less than 1 HP, he claimed it was a "different kind" of horsepower but declined to tell me what kind.

[Mike in London]

Based on this, I bet everyone's breakers are sized incorrectly, and manufacturers are selling stuff that isn't legal. For example, my radial arm saw is rated at 12 amp 110 volt. It came with a standard 110 volt 3 wire 15 amp plug. Likewise the shop vac and air compressor. All would not qualify to run on a single 15 amp breaker but they came with 15 amp plugs. Why is that?

I never had this problem with Sylvania or FPE breakers. If the breakers are really undersized, why would it trip with one 12 amp motor starting (sometimes), but not when the same 12 amp motor is starting and another 12 amp motor is already running.

I'd like to now go check on those vac's that claim to be 6.5 HP.

BTW I once had a household vacuum guy tell me thy had the most powerful machine available at 2 1/4 HP. When I checked the spec plate it was only 6 amps. When I pointed out to him that it was really less than 1 HP, he claimed it was a "different kind" of horsepower but declined to tell me what kind.

I've just told you what the codebook says and it will remedy your problem.

It's up to you at whether or not you decide to use it. You can always go spend $120.00 on a codebook to verify that I'm right. These rules are not in the Simplied Code that so many people seem to like to quote.

You're right most peoples breakers are undersized and the manufactures in many cases have the wrong cord caps installed on the their machines. One thing I didn't mention was these rules apply to induction motors only, so that would rule out your shop vac and radial arm saw, they're universal motors.

Why are you having more problems with Square D breakers, you're not they're doing exactly what they're supposed to, they're sensing an overcurrent condition and tripping. I wouldn't trust FPE breakers as far as I could throw them, Sylvania are OK, no longer made. Square D is a far better breaker than either that you've listed.