MES40 Tripping GFCI But Previously Didn't

[UncleRichard]

accidental repost. please ignore.

 

[chopsaw]

Im not an electrician

I'm not either , but used to work on some of this stuff .

Up_In_Smoke advice / info on the digital meter readings was needed . I didn't realize they were different than an analog .

unplugged spades - both terminals to MES body - OL.

That's good .

12.2 ohms of resistance across heating element.

That's a good number for an MES 40 .

-black to body 0.00 and alarm

That's the black wire that goes on the heating element ?
If so that's your problem , or some of it . Make sure it's not pinched where in comes through the body , or like mentioned above nicked casing shorting out somewhere along the line .

Also there should have been a white silicone / rubber insulator where the element passes thru the body . Keeps the element insulated from the body . Make sure you installed that .

 

[zwiller]

That's the black wire that goes on the heating element ?
If so that's your problem , or some of it . Make sure it's not pinched where in comes through the body , or like mentioned above nicked casing shorting out somewhere along the line .

+1

Not licensed either but no amateur either. I do NOT like the element wiring AT ALL. The element wires have multiple contact issues and black a bit crimped. I make it a point to keep wires like these as far as possible from one another/NEVER touch. When you move the black, unwind it and take the kinks out. Then send the extra slack of the red braid back down into the grommet/case. Both of the wires should be lose and free in the grommets. The grommets keep the wire from contacting metal. Hang in there, you are CLOSE. This stuff separates the men from the boys.

 

[UncleRichard]

Yes, the black wire is the one connected to the heating element.

Thanks ZWIller and Chopsaw. I will investigate the black/red wires, get the kinks out, etc. Will report back soon.

 

[chopsaw]

Not sure which side of line in the limit switch is on , but you might check that first and make sure you don't have something rubbing or touching in that area .

 

[UncleRichard]

Not sure which side of line in the limit switch is on , but you might check that first and make sure you don't have something rubbing or touching in that area .

Praise the Lord its fixed. It's been on for 40min at 250F so now we can have pulled pork tomorrow! Didn't trip two different GFI receptacles.

I think it was the temperature limit switch. Replaced the spade and kinked portion of the black wire at the heating element but it still went to ground. Replaced both spades and the temperature limit switch, and it was OL on the meter.

Thank you so much. This saved me from buying another one.

 

[chopsaw]

Good to hear . Enjoy .

 

[dietspam]

Praise the Lord its fixed. It's been on for 40min at 250F so now we can have pulled pork tomorrow! Didn't trip two different GFI receptacles.

I think it was the temperature limit switch. Replaced the spade and kinked portion of the black wire at the heating element but it still went to ground. Replaced both spades and the temperature limit switch, and it was OL on the meter.

Thank you so much. This saved me from buying another one.

Happy to hear it's fixed. I had the same issue. My issue turned out to be the wiring in the back like the picture of Zwiller's post. Wiring just burned up/melted and I had to fix that multiple times. Most recently replaced the heating element. An inexpensive repair.

 

[processhead]

I know this thread has been idle for a few months, but these GFCI nuisance trips are an ongoing issue for a lot of folks.

In a few cases where I have helped others troubleshoot this issue, the problem has always been isolated to current leakage between the heating element and the outer grounded coating over the element.

Since heating elements are sealed up it is not obvious by just looking at them, but the outside metallic sheath is insulated from the internal resistance element that gets power.

The high temperature insulation can degrade over time or absorb moisture. When it does, the insulation will develop a leakage current path to the outer sheath. When it does, it can trip a GFCI.

It doesn't take much current leakage to trip a class A GFCI. 5 milliamps is all they are rated for.

I usually just check the heating element first. Disconnect the power wires going to the element, connect an ohmmeter between either one of the element terminals and the other to the cabinet ground. The meter should read infinite resistance or OL. If it reads any resistance at all, there is an internal leakage path inside the element to the outer sheath.

Sometimes the leakage path that causes the GFCI to trip is caused by absorbed moisture inside the heating element. Moving the smoker to an outlet without a GFCI and powering it up for a few minutes can heat up the element and drive out the moisture.

Once the moisture is driven out of the element, the leakage current will be low enough to allow operating the smoker on a GFCI protected outlet. If the leakage is from some other cause besides moisture, this hack won't work.