I noticed the hot water hose on my washing machine (SpeedQueen Top Loader) was corroded, so I decided to replace the hoses.
I bought braided stainless steel hoses and installed them.
Everything worked fine, until I pushed the washer back to the wall and the AFCI tripped.
After some confusion, I discovered that if the braided stainless hoses touched the washer's cabinet the AFCI would trip. The trip happens as soon as the unit is plugged in.
What would cause the AFCI to trip in this case?
The washer has a 3 prong plugged and metal cabinet. The AFCI is a 15 AMP Murray Combo AFCI. The LED indicates ARC fault on some trips.
I have done the following tests:
Current between cabinet and shut off valves
I checked for current between the cabinet and the brass shutoff values. My multimeter shows less than 1.4 uAMPs of current but it fluctuates. This is with the washer plugged in. This is micro amps not mili Amps, so would not expect it to trigger the AFCI unless it is bad.
Appliance Cord
I checked each prong of the plug against the back of the washer. Only the ground plug shows continuity. The neutral and load are fine.
Why is the AFCI tripping?
For now, I have replaced the stainless hoses with rubber coated stainless ones so we can use the washer.
Any insights into the problem would be helpful. Want to note that this is a 1899, 3 story home with electrical upgrades done at various stages. I bought the home 3 years ago.
Best Answer
Many new washing machines have inverter drives on then now, and those inverters create what's called "Common Mode Noise", electrical noise referenced to ground. The washer doesn't need to be running, just plugged in for the inverter to create CM noise.
I'd say that your ground connection to the outlet or in the machine is loose or missing, so the CM noise is discharging through the machine frame itself when it comes in contact with your plumbing. Think of it as if it were a static charge built up from walking on nylon carpet and you touch a metal surface. That discharge looks like an arc fault to the breaker.
Check that inside of your washer, the bonding jumper is connected. it will be a green wire going from the machine frame to the ground terminal that the cord is connected to. If that's OK, get a receptacle tester to make sure your receptacle is connected to ground.