View Full Version : Leakage currents
rwb461
Mar 22, 2007, 02:24 PM
To make a lengthly story short, I have found leakage current of about 120ma. In a one year old dishwasher. It seems to me that if this appliance lost its' ground, that it would be a lethal condition. Is that amount of leakage normal for a "new' appliance? GFI outlets are must trip at 7ma. What is going on?
ballengerb1
Mar 22, 2007, 02:38 PM
How did you detect the leakage/short? If your washer is on a GFI it should have tripped as you suspect. Even if the green ground wire came lose it would not cause this situation but check to insure it is still securely in place. Do this with the power off.
labman
Mar 23, 2007, 04:29 AM
I would cut power to it until tkrussel checks in.
rwb461
Mar 23, 2007, 09:27 AM
How did you detect the leakage/short? If your washer is on a GFI it should have tripped as you suspect. Even if the green ground wire came lose it would not cause this situation but check to insure it is still securely in place. Do this with the power off.
Thank you for your attention. The machine is not on a GFI. The current was measured from neutral to ground. What bothers me is the high amount of leakage. If a GFI must trip at 7ma, why should my dishwasher be draining 120ma under similar circumstance that would cause a GFI to trip, IF THE GROUND IS LOST?
ballengerb1
Mar 23, 2007, 11:59 AM
First I would consider putting this machine on GFI but tkrussell's forthcoming advice will be very important. I put all electric circuits on GFI if they are anywhere near water or plumbing. This may be over protection but no live person has ever complained. I would also check the neutral to ground after completely disconnecting from the washer. This line may not be dedicated and you are picking up usage down the line. Tk will be here shortly I'm sure.
rwb461
Mar 23, 2007, 02:11 PM
First I would consider putting this machine on GFI but tkrussell's forthcoming advice will be very important. I put all electric circuits on GFI if they are anywhere near water or plumbing. This may be over protection but no live person has ever complained. I would also check the neutral to ground after completely disconnecting from the washer. This line may not be dedicated and you are picking up useage down the line. Tk will be here shortly I'm sure.
Where do I find a GFI that is'nt a must trip at 7ma?
labman
Mar 23, 2007, 03:49 PM
I stand by my original post, but after your second one, I am not sure there is a problem. Anytime a circuit has a load, there will be a voltage between the neutral and ground. Where there is a voltage, given a path through your meter, there will be an amperage. While you are waiting, why not check some of your other circuits?
tkrussell
Mar 23, 2007, 06:27 PM
Sorry, but I do not understand what "Where do I find a GFI that is'nt a must trip at 7ma?" means.
Just a few other questions:
Exactly where is this current being measured and with what type of instrument?
Why is it perceived that there is a problem with a current flow from the neutral of the DW to ground?
How is it determined that the current is from the DW?
Is there voltage measured between this neutral and ground?
A GFI will not detect a ground fault from a neutral to ground potential difference, unless there is a connection problem with the neutral. An equipment ground is irrelevant to the operation of a GFI. A GFI only trips if the current flowing in the hot is different that the neutral.