Tripping 14 Amp Breaker

[wsp617]

I bought a Generac generator rated at 3750 watts. The 120 volt outlet has a 14 amp breaker. It trips every time I use my Dewalt 12" miter saw. The saw is rated at 13 amps. After multiple attempts I plugged in my Bosch table saw. The table saw is rated at 15 amps. The saw ran fine and didn't trip the breaker.

The dewalt saw seems to work fine but I'm trying to figure out why it's tripping the breaker. I pulled both brushes and they look good. The only thing I came up with is an issue with the switch.

Anyone have any other ideas?

 

[MuleMn]

I bought a Generac generator rated at 3750 watts. The 120 volt outlet has a 14 amp breaker. It trips every time I use my Dewalt 12" miter saw. The saw is rated at 13 amps. After multiple attempts I plugged in my Bosch table saw. The table saw is rated at 15 amps. The saw ran fine and didn't trip the breaker.

The dewalt saw seems to work fine but I'm trying to figure out why it's tripping the breaker. I pulled both brushes and they look good. The only thing I came up with is an issue with the switch.

Anyone have any other ideas?

I would try plugging it into a 20 amp house receptacle and using a clamp type ammeter.

 

[toolbox5]

Too much start up / inrush voltage ? That would be my guess .

 

[Garybake]

What you are running into is startup surge current which is much higher than the nameplate running amps on the motor. You are at maximum 120 volt use with that generator (see below). The larger Table saw motor may have a capictor to help startup surge.

15 (amp) X 120 (volts) x 2 (120 volt is half of 240 rating) = 3600 Watts
13 (amp) X 120 (volts) x 2 = 3120 Watts

Toolbox5 is a faster typer than me.

 

[wsp617]

So I bought too small of a generator?

 

[MotorSeven]

So I bought too small of a generator?

Unfortunately...yep

Can you return it?

 

[Garybake]

To spinup a motor with a blade on it, I am afraid so.
3750 Watt Generator divide by 240 volts equals 15.6 amps.
Generator rating is at 240 volts.
Is it too late to return for a little larger?

 

[Raspy]

Is it tripping when you first hit the trigger, or is it tripping mid cut?

It's easy to pull more than the rated amps for an extended period (several seconds) when cutting. The breaker might have enough of a delay to hold on during the motor startup. The rated amps on the motor plate might be better if considered as continuous duty, running amps.

If you want to see a really misleading number look at Sears shop vacs They might be rated as six horsepower, but will run on a 15 AMP circuit. Sheesh.

Another example is compressors that are rated as a certain horsepower. Look at the motor plate and they say spl instead of the compressors advertised horsepower. This means they are not really what they are advertised to be.

Amp ratings on motors and compressors are designed to be misleading.