Gentlemen, my little contractor saw keeps tripping the breaker in my shop. Whenever it's under a significant load, breaking down a sheet of plywood for example ( and to be specific) the saw keeps going but the breaker trips. It happens 4 times on one sheet.

I have the saw plugged into a heavy duty outdoor power tool extension cord which is plugged into a socket. Nothing else is plugged in to that socket. Is there any way to avoid this?

Military housing so rewriting is a no- go unfortunately

Thanks in advance

I would start by trying the saw on a different circuit close to the breaker box and see if it does the same thing. If it trips on a different breaker there is a good chance there is something wrong with the saw.

If it only trips on that one circuit turn off the breaker that the saw is running on an see if there is anything else in the house on the same circuit. The total amperage should be 80% of what the breaker is rated at. If you have lights on the same circuit those will be listed in watts. Just take the watts and divide by 120 to get the amperage.

If that isn't the problem sometimes breakers get soft and trip below the amperage they are rated at. It could be the breaker needs replacing but only replace it with the same size breaker.

 

How old/abused is the blade? A new (good) blade might solve the problem.

 

i don't quite follow ? for example ( and to be specific) the saw keeps going but the breaker trips. keeps running ? if not running after breaker trips than try the saw and cord in a different outlet . like was mention breakers get weak. try a new breaker ? if saw run ok and cut's small item's , than on like the sheet good's that take more amp's on the motor , got to be breaker or cord , or outlet socket ? process of elemation . good luck

 

Thanks for the input. After looking at the breaker listing and sockets it turns out the breaker is for ALL of the sockets in the garage except the garage door opener. The breaker is listed as "Garage GFCI"

Not sure if running to a different socket will make a difference

And to answer the above post; no the breaker trips and the saw ceases running until I reset the breaker. I actually forgot to physically turn the saw off when this happened, and reset the breaker and the saw came back on with me at the breaker box. Thankfully I was smart enough to move the sheet away from the blade prior to walking to the breaker box or that would've been disastrous.

 

Thanks for the input. After looking at the breaker listing and sockets it turns out the breaker is for ALL of the sockets in the garage except the garage door opener. The breaker is listed as "Garage GFCI"

Not sure if running to a different socket will make a difference

And to answer the above post; no the breaker trips and the saw ceases running until I reset the breaker. I actually forgot to physically turn the saw off when this happened, and reset the breaker and the saw came back on with me at the breaker box. Thankfully I was smart enough to move the sheet away from the blade prior to walking to the breaker box or that would've been disastrous.

I think you answered the problem. I've had a great deal of trouble runing power tools on a GFCI breakers. The breakers sence how much power goes in and out of the circuit and can trip if there is a slight change.

 

Get out your owners manual and make sure the gauge and length of the extension cord is correct for your saw. A large gauge, long cord can be just as bad as one that is too small.

 

That would explain why for 2 years this never happened in California, but now it's happening here. The Cali shop was a detached 2 car garage, damn I miss it

 

The garage door opener is Not a GFCI outlet. Let me try running the power from that one

 

the garage can be protected by a GFCI receptacle when it is in the beginning of a branch circuit, I assume there is one in the garage somewhere. if you push test, you can see wich outlets lose power and are therefor protected by the GFCI. try eliminating the extension cord and plugging in directly to an outlet and retest.

a motor will draw whatever currrent it can to continue running, which is why the circuits that feed them need protected.

if it keeps tripping, find a buddy in CE and offer him beer to fix.

 

A GFCI will not cause a breaker to trip. And if installed properly, power tools should operate on GFCI's with no problems. If a power tool trips one, there is a problem with either the GFCI, the installation, or the power tool.

If a power tool is tripping the breaker, it is because too much current is being drawn (other than a weak breaker, rare, but it happens). Common causes of breaker tripping:
1) Inadequate wiring/breaker for tool
2) Extension cord too small for tool
3) Tool is being overloaded
4) Dull blades (See 3 above)
5) Something else sharing circuit drawing power
6) Problem with tool itself

Some uncommon problems:
1) Incoming voltage low
2)Interference from another appliance causing GFCI trip
(think inverter welder, plasma cutter, etc)

 

how long is this extension cord? even 12ga introduces alot of resistance. Assuming you need SOME cord, make sure it is not longer than it needs to be. I cant imagine the breaker is less than 15amp, and a saw shouldnt draw more than that. suggesting the drag is elsewhere.

Likewise, if there is anything else on that same circuit, it may need to be turned off.

 

Is the breaker a true GFCI breaker or does it just go to a GFCI outlet? If it's the latter, then you aren't running afoul of GFCI. Look for a pigtail (wire) coming off the breaker if it's a true GFCI. You'll need to remove the cover plate of your breaker panel to tell. Be careful not to touch anything exposed! My gut (knowing military housing) is it's not a GFCI breaker.

The breaker is tripping because either it is faulty or too much current is going through it. Inadequate wiring or too small extension cable would not increase current (though it is hazardous for other reasons like causing a fire). Feel your extension cable right after the breaker pops - is it hot (warm is ok)? If so, it's too small. Also, breakers don't typically pop quickly if you are slightly over the current rating, they take some time at the over spec current. This is so motor start up current surges don't pop the breaker.

What are the current ratings of the breaker and your saw motor? As Alchymist asks, is your saw overloaded - bogging down on the cuts? I could see a 15 Amp breaker popping on an overloaded "1.5 hp" motor. A 20A circuit that is only feeding a 1.5 hp TS shouldn't pop - even with some bogging down. If your TS bogs down and you have a nice clean blade, maybe you need to slow your feed rate.

If you aren't bogging down, your motor is under the breaker limit and you have no other loads on that circuit, the breaker is probably faulty. It's not unheard of though not that common either. Not sure how you are going to get the maint. guys to replace it. Gotta love base housing!

Edit: another way to reduce the load of your table saw is to get a thin kerf blade. The less material removed, the less the load.

 

Are the GFCI breakers difficult to install? I have a GFCI in my garage and I can't even operate and electric drill off of it.

 

Are the GFCI breakers difficult to install? I have a GFCI in my garage and I can't even operate and electric drill off of it.

it sounds like there is something else wrong with that circuit. does the GFCI trip, or the circuit breaker feeding the GFCI? take that drill to another GFCI and test it there.

a gfci is not a circuit breaker - it's a devie that monitors the current coming and going to a load/device/equipment. if current (5-6 milliamp) is not accounted for because it took another path (wire touching the cabinet etc.), then the gfci will remove the power to its receptacle connections.

a gfci breaker is installed the same as a regular, but a ground (green) wire must also be connected to the grounded bus in the panel.

 

I used to have that problem in my old shop. The landlord had so many circuits on the service panel, including a sub-panel, and the circuit in my shop was over loaded. I bought a place and wired my saw for 240v, then ran an exclusive 240 line to it. It has never tripped a breaker since.