Wednesday, August 10, 2005

Our Electrical Relay Incident


Left: Polyswitch and surge protectors (metal oxide varistors).
Center: Polyswitch on controller board.
Right: controller board. The white squiggle at the top of the board used to be a copper trace.

This is the story of our household's electrical travails this week.

It's kind of long, because:
1. a lot happened.
2. I wrote this to document the problems in case I need it for a claim.
3. it's the oddest collection of symptoms that I've seen associated with a house electrical problem.

I suppose I should mention that I consider myself pretty qualified when it comes to electricity and electronics. I studied electrical engineering in college, and I was an electronics technician for many years and have done my own electrical wiring in my homes for quite a long time. Most recently, I re-wired our garage into a home office/studio. I had never seen an exploded surge protector until this week. Now I've seen two, plus a blown Polyswitch.

On the evening of Wednesday, August 3rd 2005, everything was normal at our house as the last person went to bed around midnight. My wife Donita had done several loads of washing that day without mishap. I woke up around 4 AM Thursday, August 4th, and noticed that the digital clock in my bedroom was off. So I got up, saw that other electrical things in the house were still powered, and went outside to the circuit breaker box and felt for a tripped breaker. I found one, went back inside, and saw that the clock was now flashing 12:00. I then went to the kitchen and saw that the refrigerator was not powered (not running, no light). So I got a flashlight and went back to the breaker box, where I found another tripped breaker. When I tried to reset this breaker, it immediately tripped again. So I used an extension cord to plug the refrigerator into another outlet, and it started up immediately. Concerned that somehow some wiring within the house's walls had shorted out, but still quite tired, I went back to bed. When I got up around 7 AM, I noticed that our aquarium was not running. The heater, light, and filter pump were all plugged into a power strip. So I unplugged the power strip, went outside, and reset the tripped breaker which i had noticed earlier. It stayed reset this time. I unplugged all the aquarium components from the power strip, and plugged it back in. There was a flash from within the power strip. I unplugged it, went outside, and verified that the same breaker had tripped. I reset it, and went back inside. I started to disassemble the power strip (unplugged, of course) to see what was wrong with it, when the lights and appliances in the kitchen (where I was working) went off. I walked around the house, and everything was off. So I went back out to the breaker panel, but no breakers were tripped. The watt-hour meter was not turning at all. I walked back into the house, and within a minute or two, everything came back on. In the power strip, I discovered that a surge protector had a hole blown in it. I snipped the surge protector off, put the power strip back together, and plugged it in. No breakers blew, it worked fine (with no surge protection, of course). Later in the morning, I went to my office, and tried to turn on both of our Macintosh computers. Neither would start up. Since they were sharing a circuit controlled by a Ground Fault Circuit Interrupter, I checked it, and it was tripped. So I reset it. Now both computers would start. A few hours later, my daughter tried to do a load of wash, and the washing machine, which has a digital controller, would not start. Normally it has indicator lights which light up whenever a control is turned, but they did not light up. The (gas) dryer, on the same circuit, worked fine, and I verified that the washing machine's outlet was okay. Since it was a very hot day and the laundry room gets quite warm, I decided to wait until the next morning to look further at the washer.

Later that day (Thursday), my father-in-law, who lives next door, called to tell me that his power had been out all day. He had had a person from the City of Riverside electric service out, and he could not find the problem. The reason that the electric company guy couldn't find the problem is that my father's house's circuit breaker panel is in a different location than the meter. The electric company guy had verified that power to the meter was okay, but went no further. When I checked the breaker panel, both legs of the main 100 Amp circuit had tripped. I reset the breakers and the lights in the house came back on. I noticed that one other breaker was tripped, but since my father in law wasn't home then to tell me whether it had been tripped before, I didn't reset it. The next day my father in law told me that his TV wasn't working. When I tried resetting the last breaker, IT immediately tripped. Noting that the TV set and stereo were all plugged into a power strip, I unplugged that and reset the breaker, and it did not trip again. Then I unplugged everything from the power strip and plugged it back in while my father in law watched the breaker, and, as expected, it immediately tripped when the power strip was plugged in. So I took THAT power strip apart and discovered another surge protector, this one with a large chunk blown out of it (on the right in the first picture above). I cut the surge protector off of the power strip, reassembled the strip, and plugged it back in. The breaker didn't trip. I plugged my father-in-law's TV and stereo back in, and the TV operated normally, but the stereo would not turn on, and was buzzing from within the receiver. I unplugged it. I have not troubleshot (troubleshooted?) the stereo.

The next day, I opened up the washing machine (vintage 2001 GE) and discovered that a device acting as a resettable fuse (I believe they're called "Polyswitches") had also exploded (it looked just like that last surge protector, half blown away), and worse, several traces on the controller power supply printed circuit board had vaporised. Both the power supply board and the computer board directly under it in the washer's controller assembly had a black greasy powdery film coating them around the explosion sites (vaporised trace, insulation, and polyswitch, I guess). I cleaned them up as well as I could, replaced the blown traces with 18 gauge wire, replaced the polyswitch with a 1A slow-blow fuse (which is what was designated there on the printed circuit board's labeling), and reconnected it. The fuse immediately blew with a violent (for a fuse) pop.

While I was attempting to repair the damage to the controller boards (and having told Donita that it was likely to be unfixable, since the damage was severe and there was a lot of contamination on both boards), Donita called major appliance parts stores and found one that had a replacement controller assembly for about $165 (ouch). I replaced the controller assembly and that fixed the washer.

Donita called the power company, and they admitted that there had been a "relay incident" in the middle of that night. "We do the best we can," he said. He said he'd send us a claim form, so hopefully we'll be able to get reimbursed for the washing machine controller, and my father-in-law for the stereo receiver. I'll let you know what happens.