Workshop power problem!

[fdfrye]

All,

Here I go again with a ridiculous question but...

I installed a dedicated shop circuit in my breaker box. Following what I thought were building code rules, I installed a 20-amp GFCI circuit breaker so I would not have to put in GFCI outlets everywhere. Everything worked great for a while, until I recently got a new router table and started trying to dust off my old Hitachi M12V. The router worked (and works) great on my other electric circuits but immediately trips the GFCI circuit. All my other power tools work fine on the new circuit. Even through extension cords and even while running two or three items. 1100 CFM Jet Dust collector, Jet 10" table saw, 14" Grizz Bandsaw etc. What gives? This is a 3 1/4 HP router, but I never had any problems before. Any tips? Someone suggested I try plugging it into a GFCI outlet in the bathroom or kitchen to see if it trips. I'll post that works out.

Thanks guys!

 

[fdfrye]

Update:

I went ahead and tried the GFCI outlet in my bathroom. No problems. I ran it through all variable speed settings as well. Running a router in the bathroom....first time for everything...

 

[TracyP]

I would check for a loose connection in the new circuit. A lug that is not securely tightened. That would be my only guess.

 

[Jim M.]

For what its' worth... I "upgraded" all my outdoor power grids from outlet based GFCI to 20-amp GFCI circuit breakers at work. We run mostly sound equipment, theatrical lighting units, and fans etc. I've spent a summers' worth of headache s and we've now gone back to the old configuration with zero problems. Our electrician told us they (20-amp GFCI circuit breakers) are weak on hard start-ups and once tripped, they get weaker each time. Just my two cents. Jim

 

[Bigdog72]

Did you get Ground fault or arc-fault breakers? The arc-faults trip when it senses an arc (like commutator v brushes in a motor).

 

[mkepke]

Danny - it's not a ridiculous question. Unfortunately there's no easy answer either.

IF the GFCI is working properly, it's seeing an imbalance between the hot and the neutral. You say this only happens with the router and not any other comparable motor loads and only on start up ?

It suggests that there is current leakage with the router. Is it possible to (electrically) insulate the router while you turn it on ?

The other option - which your testing suggests is correct - is simply that the GFCI breaker is false tripping. Replace the breaker.

BTW, you do know you can use a single GFCI outlet to protect all downstream outlets, right ? Usually a lot less coin than a breaker.

-Mark

 

[fdfrye]

Thanks guys. If it helps, I think this is the breaker I bought:

http://www.homedepot.com/webapp/wcs...Id=10053&productId=100002959&N=10000003+90282

It would seem that the breaker itself is faulty, though it still doesn't make sense why it would only "fault" with my router. It may be some combination of weak/malfunctioned breaker and harsh start up from the router. The funny thing is, if I remember correctly, Hitachi made a big deal about their "soft start up" and I assumed starting at the lowest speed would have made a difference too. I suppose not...

 

[Truefire]

Hey buddy the electrical issue that you are experiencing with the GFCI (Ground fault circuit interrupter) breaker is dust builds up inside our woodworking tools and there will almost always be some voltage leakage --minute--and not felt but there will be some leakage current due to the dust around the windings and such. This creates an imbalance in the milliamps measured on the nuetral wire returning to that breaker with that of the hot leaving it.

The other thing is that locked rotor amps of that router are creating a little bit more amperage draw than what your breaker can withstand. Breakers are manufactured to trip at 80% of their stamped rating.

GFCI breakers/receptacles are simply very sensitive by nature. They are simply doing their job. But if it were me, I would replace everyone of them with a standard breaker and standard electrical outlet. Most all tools are double insulated now days and have thermal overloads as well as grounds attached. This double insulation of power tools should under most all working conditions keep one from getting shocked. If you were working outside in a wet yard with power tools and such you might want a gfci powerstrip or such.