Lighting Contactor

[laketime]

I have a 225 amp lighting contactor controlling a panel of heat tape. The heat tape was not working and we found the contactor was staying in the open position. The control is 120v electrically held open and closed which seems to be operating correctly. We moved the contactor manually a few times then it seemed to work properly again. Now the customer says it is no longer working and staying in the open position. Ideas?

 

[templdl]

I have a 225 amp lighting contactor controlling a panel of heat tape. The heat tape was not working and we found the contactor was staying in the open position. The control is 120v electrically held open and closed which seems to be operating correctly. We moved the contactor manually a few times then it seemed to work properly again. Now the customer says it is no longer working and staying in the open position. Ideas?

I would first check to see what it does when you are watching to as you are activating the 120v closing control which it doesn't appear that you have verified yet. Is it even getting the 120v pulse at all. It may be a control issue and not the contactor at all.

 

[kmh]

troubleshoot, then repair

troubleshoot, then repair

I would first measure to see if there is any voltage across the coil (which you probably already did). If there is partial or full voltage across the coil, then you have another problem - finding out why there's voltage. If it's zero volts then I'd be disassembling and cleaning the contactor, or replace it.

 

[laketime]

Thank you both. We showed up to check it out again...and of course it was working fine. We turned it on and off with the controls 5 times over a 30 minute period and it performed flawlessly. Fixed another one! lol :blink:

 

[Jraef]

Thank you both. We showed up to check it out again...and of course it was working fine. We turned it on and off with the controls 5 times over a 30 minute period and it performed flawlessly. Fixed another one! lol :blink:

For what it's worth, I had a call like that years ago. Turned out there was a time clock in the system and nobody who worked there now was aware of it. The time clock was essentially an enabler and time limiter in that it didn't turn the lights on, it just enabled them to turn them on manually after 5:00 every day and if anyone forgot to turn them off, it would kill the coil power after midnight. Probably installed in the 70s to save energy. But nobody knew that and when I got the call, it was because someone was checking for burned out bulbs during the day, when the timer didn't allow them to turn them on. So they assumed it was the contactor and replaced it. I was called after that didn't fix it. I traced the control circuit and found the timer tucked into the back of a janitor's closet, but they no longer had a janitor so nobody ever when in there. I just moved the time clock to be next to the lighting switch bank, then put a sign on it explaining how it worked.