LumberJocks

Table saw tripping GFCI outlet

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by LJD4662 posted 06-20-2014 02:08 PM 3357 views 0 times favorited 21 replies Add to Favorites Watch
View LJD4662's profile

LJD4662

34 posts in 1166 days


06-20-2014 02:08 PM

I have an older craftsman 113 table saw with a 13 amp motor that is currently tripping the GFCI outlets in my garage. This problem began about two weeks ago and up until then I have not had any issues. Yesterday I needed to make a few cuts so I ran an extension cord to a non GFCI outlet and ran the saw with no issues. Does anyone have any ideas of what the problem could be? Do I replace the GFCI with another GFCI or go with a regular outlet? Thanks in advance.


21 replies so far

View Fred Hargis's profile

Fred Hargis

3945 posts in 1959 days


#1 posted 06-20-2014 04:00 PM

GFCIs can go bad, does it trip with any other tools? If no, I’d say you might want to check your saw for a ground fault….if yes, replace the GFCI. There’s probably several other things to check, but you have to start somewhere.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Ralph's profile

Ralph

166 posts in 1599 days


#2 posted 06-20-2014 04:07 PM

Just because the saw ran OK in a non-GFCI outlet, and you didn’t get a shock, doesn’t mean that all is OK. The problem may be a high resistance fault from the hot line to ground.
Check out the GFCI outlet as Fred Hargis suggests.
If the GFCI is OK, then I would first UNPLUG the saw, then turn the power switch on and check the resistance, at the plug, from the hot line/blade to the ground line/pin. After the measurement, don’t forget to TURN OFF the power switch. The resistance reading should be infinite, in your case it may not be, which probably means faulty insulation somewhere.
Good luck.

-- The greatest risk is not taking one...

View jonah's profile

jonah

687 posts in 2764 days


#3 posted 06-20-2014 05:52 PM

You can test a GFCI outlet with one of those little $5 outlet tester things. They have a button on them that creates a ground fault, which should trip the outlet.

Any hardware store should have them, as do the big orange and blue boxes. I’d try one of those first, to be sure the outlet is functional.

View MrRon's profile

MrRon

3926 posts in 2709 days


#4 posted 06-20-2014 06:49 PM

GFCI’s do wear out. A table saw may run on 13 amps, but the amperage at start up is now exceeding the GFCI’s limit. Either replace the GFCI, or eliminate it altogether. I don’t feel a GFCI is necessary in a shop, unless you do your own wiring without good knowledge of electrical circuits. GFCI’s are more commonly used in places where moisture is present, like in a kitchen, laundry or bathroom.

View whope's profile

whope

137 posts in 1911 days


#5 posted 06-20-2014 07:04 PM

GFI’s aren’t normally put in unless required by code. A garage floor can easily become damp.

They aren’t that expensive so if you need to replace it don’t use a regular plug.

-- Measure it with a micrometer, mark it with chalk, cut it with an axe.

View ChrisK's profile

ChrisK

1809 posts in 2547 days


#6 posted 06-20-2014 07:38 PM

The insulation on the old motor may be going. I have an old craftsman as well, vintage 1950’s. The original motor leaked enough voltage that when I touched the saw and the water pipe that was on the wall next the saw you would get a shock. Put on a new motor, no more shocks.

Keep the GFCI!

-- Chris K

View jonah's profile

jonah

687 posts in 2764 days


#7 posted 06-20-2014 07:40 PM

No properly-working tool should be tripping a properly-functioning GFCI outlet.

View WhyMe's profile

WhyMe

615 posts in 1027 days


#8 posted 06-20-2014 07:59 PM

MrRon replied: GFCI’s do wear out. A table saw may run on 13 amps, but the amperage at start up is now exceeding the GFCI’s limit. Either replace the GFCI, or eliminate it altogether. I don’t feel a GFCI is necessary in a shop, unless you do your own wiring without good knowledge of electrical circuits. GFCI’s are more commonly used in places where moisture is present, like in a kitchen, laundry or bathroom.

Well the part about GFCT outlets wearing out is correct, but the rest of your statement is a little off base. GFCI outlets don’t trip on over current. Also they are required in garages/shops that have concrete floors on grade and it’s not because of possible moisture. They are for ground fault protection and standing on a concrete floor makes you a good path for any fault current.

View LiveEdge's profile

LiveEdge

486 posts in 1086 days


#9 posted 06-20-2014 08:06 PM

I would be careful about advising just removing the GFCI outlet. The circuit may include other parts of the house and it’s possible there is a bathroom on the circuit which would require such an outlet. As an example, the GFCI for our powder room is not actually IN the powder room.

Is it possible the saw was tripping because something else on the circuit was also running at the same time? (portable AC unit, etc) You put the saw on another plug which happened to be on another circuit and the problem went away?

View TheFridge's profile

TheFridge

5765 posts in 952 days


#10 posted 06-20-2014 08:22 PM

It was the gfci not the breaker.

Do this, plug in another tool that has a ground. If it trips. Get another grounded tool. If it trips. Bad gfci. I replace them all the time. Over current will kill em over time.

If it’s not the gfci then logic states bad saw.

Do not buy a tester. It won’t test the gfci under load which is what you need. So just plug in another grounded tool. I do it all the time. Electrician 15 yrs bud.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View LJD4662's profile

LJD4662

34 posts in 1166 days


#11 posted 06-20-2014 08:22 PM

Its very iffy when its going to trip, but once it starts it will trip every GFCI outlet in my garage. I just started the saw on a GFCI outlet and it ran fine with nothing else on the circuit. Yesterday I made it half way through a rip before it tripped. After that it tripped every few seconds. I think the only other thing on the circuit at that time was my cell phone charging.

View Shawn Masterson's profile

Shawn Masterson

1297 posts in 1414 days


#12 posted 06-20-2014 09:07 PM

A side note. If you have #12 wire in the box make sure to get a 20 amp GFCI, not a 15 amp. Personally I don’t have them any where that isn’t within 3 feet of running water. There are none in the shop. This is a choice and yes I know that if I sell FHA I will have to put them in.

View TheFridge's profile

TheFridge

5765 posts in 952 days


#13 posted 06-20-2014 10:44 PM

Put in 20A gfci where you load will be above 10A or thereabouts. Most gfcis will be on a 20A ckt w #12s, laundry, kitchen, bathrooms require a 20A ckt when house is built.

A 15-20$ replacement gfci will be cheaper than a new motor so I’d suggest trying that 1st.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View LJD4662's profile

LJD4662

34 posts in 1166 days


#14 posted 06-20-2014 10:54 PM

I just got finished rough cutting legs for a table I’m making. Made 8 cuts, it tripped on 4 of them. Each time I unplugged and checked the resistance like Ralph described and my meter isn’t measuring any resistance. I will try changing the outlet tomorrow.

View English's profile

English

517 posts in 943 days


#15 posted 06-21-2014 02:54 AM

GFCI receptacles are required by National Electric Code for receptacles in Garages. I wouldn’t take them out. That saw should only be plugged into a 20 amp circuit due to the in-rush at start-up.

-- John, Suffolk Virgina

showing 1 through 15 of 21 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com