Pellet Stove and GFI - basic troubleshooting.

[webbie]

There was an earlier thread about a Pellet Stove tripping a GFI. I and other had responded that could mean various things.

Just as an update, although not exactly related, my mac mini was tripping my GFI after 2-24 hours. I knew it was the mac, because nothing else made the circuit trip. I called them and asked for a new brick power supply, telling them (they didn't really know chit) that this must be a power supply problem.

Sure enough, the new brick came the next day, and it does not trip the GFI any longer.....

As to the Pellet stove doing the same, it could be the power cord or even possibly the power supply in the stove itself. But, it also could be a bad GFI outlet and the connections in the panel, etc.

The first order of business, besides plugging it into a non-GFI outlet, might be to switch out the Pellet Stove power cord....if it has an easily replaceable one. If it continues to trip after that, you might have your circuit and GFI outlet checked and the outlet replaced. If it still trips, that does point to a leakage of sorts somewhere in the Pellet Stove electronics.

 

[begreen]

Interesting info about the Mac. I agree with the analysis procedure but would add it that with a stove possibly may not be in the electronics. I have found ground shorts in other areas like an errant strand of wire at a spade lug connector. Also check wiring bundles for chaffing and frayed insulation.

 

[Kenny1]

I don't know about swapping out the line cord. Unless it is damaged and the netural is making contact with the ground, there should be no leakage in the cord. You could use an ohm meter to check for damage on the line cord (neutral to ground should be an open circuit).

I think if my GFI breaker was tripping when the pellet stove was on, I'd first locate everything else on the circuit and remove it. Then see if the breaker trips with just the stove on the circuit. If the GFI still trips, you might then run an extension cord to a different circuit.

As BeGreen points out, damaged wire bundles can cause problems. Some of these you may be able to find with an ohm meter (unplug stove and measure resistance from neutral to ground - should be an open circuit). Some might require some digging into the guts of the stove (and a schematic).

One issue with the GFI breakers is that they are pretty senstive. I thnk they trip at maybe 10mA or less. 3.5mA is considered lethal. There are a couple of electrical safety standards that allow for up to 3.5mA of leakage current (IEC 950 I believe allows this). If a number of these items are on one circuit, it could trip the GFI, even though they are all operating normally.

And of course, leakage current is a balancing act in the design of a power supply. There are standards on how much noise and hash electronic equipment can couple onto the AC mains, and you want your supply to be immune to noise from the AC line. You reduce this with capacitors on the AC inputs. However, all caps have some leakage. Bigger caps give better noise immunity (and less noise coupled out onto the mains), but raise the leakage current.

Cheers


Kenny