I have a Furnas mag starter that was working until Tuesday. It's on a 3 phase 5 hp compressor, doesn't work now. How do you test the coil?
Testing a mag starter coil
- Thread starter 930dreamer
- Start date
rockwithjason
Well-known member
a simple continuity check is all you need. the coil will either pass current or it is burned open. you can also pull it out and visually inspect it. smelling for burned smell works too
Aceman
Well-known member
Hit the coil with power. You'll know in an instant if it pulls in or not.
hofferwood
Well-known member
Yes, if you let the factory installed smoke out of it, it's done! That smoke is NOT replaceable
.Chuck
It's on vacation until next Monday. Try it again after the weekend! Either method mentioned above will work.
Dave
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MEDICAL MARIJUANA NEWS
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nehog
Well-known member
If it energizes, keep it powered for a short while (5 to 15 minutes) then check (carefully) temperature. If hot, it has shorted turns. The reason for this is that a shorted turn acts like a transformer with a shorted secondary winding, and it tries to flow infinite current through the shorted winding(s). (This, of course, only applies to AC coils.)
OP
Well I know I have 240 3 phase into the mag starter but nothing through the coil. It doesn't smell like smoke, makes no sound either. Thanks.
ok dreamer try this and record (write down info)
check voltage with volt meter on A-B-C to ground and inbetween legs A to B, B to C,C to A legs at top of starter, then if you do have voltage on all three legs press the reset button to reset the overloads if your starter still doesnt work then check the fuses on the control circuit and if that still doesnt work then you will need to check pressure switch and any other circuit cutting items you have in line. Post results of testing if it doesnt start for further help needed.
If you dont have meter or dont know how to test you can manually push in coiland if it runs you know you have voltage and your control circuit is bad. if you do this BE CAREFUL NOT TO BLOW UP YOU/STARTER.
check voltage with volt meter on A-B-C to ground and inbetween legs A to B, B to C,C to A legs at top of starter, then if you do have voltage on all three legs press the reset button to reset the overloads if your starter still doesnt work then check the fuses on the control circuit and if that still doesnt work then you will need to check pressure switch and any other circuit cutting items you have in line. Post results of testing if it doesnt start for further help needed.
If you dont have meter or dont know how to test you can manually push in coiland if it runs you know you have voltage and your control circuit is bad. if you do this BE CAREFUL NOT TO BLOW UP YOU/STARTER.
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OP
I checked the incoming voltage with a digital volt meter, all okay. The circuit goes through a disconnect with fuses, I ohm'ed them their good, then to the mag starter with a reset. I have 240v into the mag starter but the starter won't engage, the heaters are good also. I'll look at the pressure switch, I'm out of town, but will look at it when I return. A friend has a compressor business and will have a look also. thanks