I'm an Appliance repair guy with a Journeyman License in Residential work. I haven't done Electrical in many years, so I hope I'm still qualified to post a query here. I need help!
I have a customer who owns an electronically controlled washer. It's giving her intermittent problems (SOMETIMES it'll simply shut down on final spin... she'll wait 20 minutes and fire it right back up) which I'm unable to duplicate at the scene.
The machine is a Whirlpool built Kenmore. I recall during a Tech class I attended at Whirlpool, the Instructor mentioned a similar problem with their Elec. Control Ovens. The problem couldn't be duplicated during the day... it turned out to be the Fluorescent lighting in their kitchen dirupting the ERC while she cooked at night. He didn't say what the fix was.
If this is the same problem, how would I know and what is the fix? Is there a filter to install or should I ask her to do laundry in the dark?
I also seem to recall that there is a test that can be performed on a Home's wiring that will identify LC and its' effects on nearby circuits.
Intermittent problems are the hardest to diagnose, especially at the beginning when all the evidence is third party anecdote.
Your background in residential wiring along with current appliance experience puts you in a unique position and should help.
I'd continue by eliminating the obvious: 1. Verify that the circuit is grounded and that the appliance itself is being electrically grounded through the cord and receptacle. 2. Are there fluorescent fixtures? You didn't actually say, but I assume so. The fluorescents must also be solidly grounded. 3. Temporarily disable any nearby fluorescent (don't forget any compact fluorescents) and supply light with incandescent sources.
I've had this same intermitant problem in the past with my own 2 Whirlpool washers.
One instance turned out to be arc flash on the dial contacts, replaced dial and work perfect till it died completely.
Second wash the lid (safety) switch connection, while going thru the spin cycle it wld shake loose just enough to interupt it but wld be fine afterwards. I cut the connectors off and soldered. no probs since.