keeps burning out a relay for the outside condensor motor

chrisachvac · 06-15-2012, 01:25 AM

having trouble at work this one place keeps burning out a relay for the outside condensor motor been there 4 times Cannot figure out what the hells causing this to happen its driving me insane we put a little fuse popper on the circuit to protect it from burning out again but thats just putting a bandaid on it for now I gotta quit running the **** through my mind!It works great while your there everythings drawing the right amps running good like clockwork in 2 days they call again!

any ideas??????

**beenthere** · 06-15-2012, 06:04 AM

Someone put a larger condenser fan motor in?

chrisachvac · 06-15-2012, 07:03 AM

nope all original parts motor runs fine not too many amps its the control coil of the relay that keeps failing 208-240 volt coil I have 211 volts to that somethings rotten in denmark anyways no matter if the thing goes they can still run one of the indoor units its a duel zone mini split samsung Ill think on it this weekend they make relays that sense amp draw instead of using voltage that would cure the problem just have to do a little creative rewiring pretty much got the wiring diagram impressed in my brain now!

Yoyizit · 06-15-2012, 01:13 PM

Coil is failing by shorting or failing by opening?

High temps. cause insulation to fail.

DC coil resistance is lower than AC coil impedance and may not accurately predict coil current.

All electromechanical relay armatures are pulled in by current but potential relays have a high coil resistance and a narrow pull-in to drop-out range.

If the steady-state values read OK you could have 120v transients going into the coil due to an intermittent short. If they are short enough the fuse may not melt.

Don't change circuitry until you solve this. There is something that you are assuming that is not true. The work is to find out what it is.

Missouri Bound · 06-15-2012, 09:09 PM

What voltage is available at the equipment? I'm of the opinion that somewhere along the line some wires got switched around and you may have an instance where there is an excessive voltage put to the coil when some other switching is taking place. There is a surge of some kind creating this problem. Any other equipment having this issue? Is there a schematic on the equipment that you can use to verify all connections? It looks bad to keep coming back to fix the same thing over and over.