Yet another electrical question on a WW tool

Page 1 of 4  
In my shop I have two general purpose electrical circuits that I connect ev erything to except the big machines. They are 20 amp (120VAC)circuits with 12 gauge wire. Each circuit starts with a GFCI outlet and then a chain of normal outlets. All outlets are 20 amp.
On one circuit I have my Yorkcraft 6" jointer plugged in. I've had this a few years. It's been lightly used with no prior problems.
This evening I was jointing a piece of 1 x 6 maple set to take off less tha t 1/64 per pass. After a bit, the GFI would pop. Thinking this might be t he GFCI outlet, I connected the jointer to the second circuit. Same proble m. The only other piece of equipment running was the DC which is on a sepa rate 240VAC circuit.
The circuit breaker (20 amp)never pops. The GFCI outlet is maybe 6' from th e panel and the second outlet (jointer) is about 8-10' from that.
The jointer has a 1 hp motor (running at 120VAC)and, when I pulled the cove r off, the motor was barely warm. No dust buildup either since I have this connected to my DC.
I have done a baby crib's worth of (soft)maple and 2 large bookcase's worth of cherry without incident. The piece I was working on was a piece of the leftover maple.
Any thought why this would cause the GFCI to pop and not the circuit breake r? Also, what would I look for with respect to the cause. I bought the jo inter new 8 or 9 years ago and it has been lightly used.
Thanks,
Bill Leonhardt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 6:50 PM, Bill Leonhardt wrote:

Have you tried plugging another relatively heavy draw tool into the circuit to rule out your jointer?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 6:50 PM, Bill Leonhardt wrote:

...

...

breaker? Also, what would I look for with respect to the cause. I bought the jointer new 8 or 9 years ago and it has been lightly used. ...
GFCIs work on the current imbalance between the two legs and trip as low as 5-6 mA. What this indicates is that the motor now has a leakage path that ends up being above the GFCI threshold--it probably started off at just barely under and know with some age there's some insulation degradation that has let it now be just over instead of just under.
Your choices as I see it are--
a) replace the GFCI w/ a different/newer one and see if goes away for at least a while,
b) replace the motor w/ one that doesn't have the leakage current. It's highly unlikely you'll be able to change its characteristics any although despite no heavy dust buildup you might try blowing it out thoroughly w/ compressed air to see if internal dust could be contributing to the problem, or
c) do away w/ the GFCIs
Oh, there's no fluorescent lighting on the circuit is there?
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 7:13 PM, dpb wrote: ...

And, while it's less likely given the two circuits both behave the same now, look for and check all circuit connections to eliminate any high impedance ones (relatively) that could contribute to the small imbalance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

As someone who has been considering installing a ceiling dust collector (or something else) on the same circuit as fluorescent lighting, is there an issue here I should know about? Why did you raise the concern?
Thanks, Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 8:55 PM, Bill wrote:

RFI from the fluorescent is sometimes factor in false GFCI trips...there shouldn't be any need for GFCI on such a circuit.
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

Thank you. Indeed, my lighting is not on a GFCI circuit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That would be my first choice.

...and that if a) didn't work.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Leonhardt wrote:

------------------------------------------------------------------ "dpb" wrote:

---------------------------------------------------- I vote for "C" above.
The GFCI is a bit much in this application, IMHO.
Lew
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That might not be possible. I have a basement shop, and I am required by code to have 12g wiring and gfci on each ckt.
I would try a new gfci, it's cheap enough to give it a try.
--
Jeff

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 7:53 PM, Lew Hodgett wrote: ...

...

...

...
That's certainly what I'd do, too, but figured I'd be conservative... :)
I don't have any on the place, anywhere, and have survived so far. I have considered putting one on the heater circuits for the stock waterers as the one place could see it being a benefit but they've been there for 60-year or so and haven't ever been a problem so it seems like a solution looking for a problem more than a cure...so haven't ever gotten one of them round tuits.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 7:39 PM, Mike Marlow wrote:

I'd find that more convincing if it weren't both failing at the same exact time...that's just _too_ coincidental...

It's certainly the simplest...

Well, in the days of GFCIs originally motors were notoriously high-enough leakage to cause them to trip. That a presumably Chinese-motor on an import tool has enough after a few years to now cause a trip (on two separate ones, no less) is less remarkable occurrence to me than the two GFCIs failing identically.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 14 Oct 2013 20:39:14 -0400, "Mike Marlow"

Actually not uncommon.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
GFI is getting wore out? Problem with the windings and or arcing in switch/motor? The GFI is getting input either from the machine or the GF! i s wore out? Are the plugs and receptacles in good condition? john
"Bill Leonhardt" wrote in message
In my shop I have two general purpose electrical circuits that I connect everything to except the big machines. They are 20 amp (120VAC)circuits with 12 gauge wire. Each circuit starts with a GFCI outlet and then a chain of normal outlets. All outlets are 20 amp.
On one circuit I have my Yorkcraft 6" jointer plugged in. I've had this a few years. It's been lightly used with no prior problems.
This evening I was jointing a piece of 1 x 6 maple set to take off less that 1/64 per pass. After a bit, the GFI would pop. Thinking this might be the GFCI outlet, I connected the jointer to the second circuit. Same problem. The only other piece of equipment running was the DC which is on a separate 240VAC circuit.
The circuit breaker (20 amp)never pops. The GFCI outlet is maybe 6' from the panel and the second outlet (jointer) is about 8-10' from that.
The jointer has a 1 hp motor (running at 120VAC)and, when I pulled the cover off, the motor was barely warm. No dust buildup either since I have this connected to my DC.
I have done a baby crib's worth of (soft)maple and 2 large bookcase's worth of cherry without incident. The piece I was working on was a piece of the leftover maple.
Any thought why this would cause the GFCI to pop and not the circuit breaker? Also, what would I look for with respect to the cause. I bought the jointer new 8 or 9 years ago and it has been lightly used.
Thanks,
Bill Leonhardt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, October 14, 2013 7:50:23 PM UTC-4, Bill Leonhardt wrote:

everything to except the big machines. They are 20 amp (120VAC)circuits wi th 12 gauge wire. Each circuit starts with a GFCI outlet and then a chain of normal outlets. All outlets are 20 amp.

a few years. It's been lightly used with no prior problems.

hat 1/64 per pass. After a bit, the GFI would pop. Thinking this might be the GFCI outlet, I connected the jointer to the second circuit. Same prob lem. The only other piece of equipment running was the DC which is on a se parate 240VAC circuit.

the panel and the second outlet (jointer) is about 8-10' from that.

ver off, the motor was barely warm. No dust buildup either since I have th is connected to my DC.

th of cherry without incident. The piece I was working on was a piece of t he leftover maple.

ker? Also, what would I look for with respect to the cause. I bought the jointer new 8 or 9 years ago and it has been lightly used.

Follow-up
I have my lights (fluorescent) coming off the main house panel and all else coming off a sub panel for the shop. That way I can lock out all machines and outlets when I have grand kids working in the shop.
The shop is in my basement and I believe that general circuits (those not d edicated to a specific use) are required have a GFCI.
All my outlets and plugs are in good shape but the GFCIs are 9 or 10 years old. Still, it's hard to imagine they both failed at the same time.
I will see if I can get compressed air into the motor (although I think it' s sealed)to further blow it out. My 13" Rigid planer ran OK on one of the circuits since I got enough of the board flattened before the jointer quit to plane both sides.
I'll report back after the air trial.
Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 14 Oct 2013 19:24:10 -0700, Bill Leonhardt wrote:

I recently had our house inspected for a sale. The inspector required a GFCI on any receptacle within 5' or so of a faucet, but not on any other circuit. It may be different for new construction or for your state but I've never heard of an overall requirement for a GFCI.
--
This message was for rec.woodworking - if it appears in homeownershub
they ripped it off.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Leonhardt wrote:

I have my lights (fluorescent) coming off the main house panel and all else coming off a sub panel for the shop. That way I can lock out all machines and outlets when I have grand kids working in the shop.
The shop is in my basement and I believe that general circuits (those not dedicated to a specific use) are required have a GFCI. ----------------------------------------------------------------- Don't think so.
If you follow that logic, EVERY receptacle in the house would require GFCI protection which obviously is not the case.
Do you have water plumbed into your shop?
If so, you may require GFCI protection if receptacle close to a water faucet, otherwise not.
Try replacing the GFCI receptacle with an industrial grade receptacle (5262), which you may not be able to get at HD, but may have to get from an electrical distributor.
It will be a heavy duty, 20A receptacle, that may cost as much as $10 for a single unit.
Lew
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Forgot to add, look for a Hubbell 5262 receptacle, every electrical counter person will recognize what you are trying to find.
Lew ----------------------------------------------------

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm thinking they are treating the basement as they do an exterior wall because of the (potential) dampness.
--

dadiOH
____________________________
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 10/14/2013 9:24 PM, Bill Leonhardt wrote: ...

If you're covered by NEC in current area, theoretically that's so...another case where the cure is worse than the disease in many cases. :(
...

An potential alternative that fixes the problem longer term if it turns out the motor leakage has gotten high enough for even a replacement GFCI would be (presuming it's a dual-voltage motor) to switch it over to a 240V circuit--they're not under the NEC mandate. I'd prefer it on the higher voltage anyways if possible.
Again, don't forget to check motor connections at the plug and motor end to ensure they're as clean and tight as possible to eliminate any chance of a higher impedance connection being the final straw on the current imbalance.
Since you're hitting both circuits, it's pretty clear the cause is the motor/wiring there, not the rest of the wiring altho again it's the total so a little here, a little there, it all adds up...but that both circuits cause it pretty much rules them out.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.