Starter Overload Burned Up on my blowers

[Buzzie8]

My blowers quit working today and when I opened the control box that houses the three starter solenoids everything was black and looked burned. After rooting around in the box and cleaning things up, I noticed that one of the overloads for the starter solenoid was where the fire originated. I still do not have it up and running because after replacing the starter solenoid and overload I noticed the relay that was positioned next to the fire looked like it suffered damage from the fire as well. I will replace that tomorrow because I did not have a spare. After I replace the relay socket and relay. I am assuming that they will run but I am not comfortable as to why this might of happened. I will see what amps the motor is pulling once I get it running. In my estimation, the whole purpose of the overload is to protect from a fire much like a fuse would, correct? Oh well, just another day at the wash!

 

[MEP001]

If the overload is burned up, it was either defective or the wiring connections weren't tight. The overload is nothing more than a heavy wire with a lighter heat-conductive wire wrapped around it to trigger the overload to trip if too much current is drawn. You might even make sure the overload is wired properly - there's nothing in it that breaks the 3-phase power going through, it only shuts off the control voltage to the contactor coil when it trips.

 

[Buzzie8]

I am glad you mentioned a loose wire connection. I was thinking this could be the culprit as well. I am pretty sure that all three starters are wired correctly although I did have a problem about a month ago when the output was tripping all three starters in and out uncontrollably causing a quick off and on energizing of the solenoids. I replaced all three and thought that I found a short causing the output to turn them on and off. I am hoping that when I installed the starter that caught on fire that the one leg was not tightened completely. The whole experience over the past month has me somewhat confused.