Winston
12-19-2004, 06:09 PM
One night I got a call from the attendant saying that dryer #10 sounded "like it's falling apart". She marked it out of service. When I arrived there was a 3-4 inch nail protruding through the basket causing a loud scraping noise... No problem. Removed the nail, and the out of order sign. Next morning I came in to find an out of service sign on the dryer. A note from the attendant indicated a "reduced heat" problem.
I started the dryer, and the burner immediately lit, burned for about 20 seconds, then went out. To check it out, I checked for voltage on each terminal of the thermostat. 110 volts on each terminal. Now it gets strange. When the dryer was turned off, there was still 110 volts on each terminal of the thermostat. This voltage should come to the thermostat via the various limiting switches, and should have originated with the red wire coming from the motor. I disconected the splice near the motor on the red wire. There was voltage on the disconnected wire (not on the motor side)! Where did this come from? Decided to look at the main power wire connection for the dryer. It was hooked up backwards... Hot wire to white wire, and neutral to black. Switched the wires and now there is voltage on one side of the thermostat (when running) and none on the other. So the thermostat is not working.
Opened the lint door and removed the thermostat bulb from its mounting. The previously removed nail was so long that it had severely dented the bulb as the drum rotated. Replaced the thermostat (being very careful not to kink the copper tubing) with a new RSPC unit. Fired it up and everything was OK.
Came in the next day and it was out of service again... no heat. Checked for voltage on both terminals of the new thermostat. It only had voltage on one terminal. So the new thermostat is defective. Put on a second new one, and everything has been OK for a week now.
Whoever said it was easy!
I started the dryer, and the burner immediately lit, burned for about 20 seconds, then went out. To check it out, I checked for voltage on each terminal of the thermostat. 110 volts on each terminal. Now it gets strange. When the dryer was turned off, there was still 110 volts on each terminal of the thermostat. This voltage should come to the thermostat via the various limiting switches, and should have originated with the red wire coming from the motor. I disconected the splice near the motor on the red wire. There was voltage on the disconnected wire (not on the motor side)! Where did this come from? Decided to look at the main power wire connection for the dryer. It was hooked up backwards... Hot wire to white wire, and neutral to black. Switched the wires and now there is voltage on one side of the thermostat (when running) and none on the other. So the thermostat is not working.
Opened the lint door and removed the thermostat bulb from its mounting. The previously removed nail was so long that it had severely dented the bulb as the drum rotated. Replaced the thermostat (being very careful not to kink the copper tubing) with a new RSPC unit. Fired it up and everything was OK.
Came in the next day and it was out of service again... no heat. Checked for voltage on both terminals of the new thermostat. It only had voltage on one terminal. So the new thermostat is defective. Put on a second new one, and everything has been OK for a week now.
Whoever said it was easy!