Kohlback electric motors 1

[larry5000]

Hi, having problems, it is a Kohlback 7.5 hp 220 volt motor. It been sitting for a couple of years, in a building, put power to it and it ran for about 2 hr, then it started to kick off control, we push reset, run 10 min and then kick off, then kick off as soon as you turn on. Check amps and they are high. Checked all 3 Capacitors and one was bad, install new one, turned on power and blew up (with smoke and bang) 1 of old Capacitors, put another 1 in, same thing happened. I wrote myself a diagram when I took off wires, I think I have the wires right but now I am not sure. Anybody know where the wires go, or maybe knows whats wrong, or do I need new motor. Any help would be appreciated. Thank You, Larry.

 

[jraef]

1 phase or 3 phase? If it's 1 phase, I'm having trouble envisioning 3 capacitors in the circuit somehow. If it is 3 phase, those would be power factor correction capacitors.

Either way, capacitors go bad when sitting for a long time, it's not surprising. They needed to be "reformed" before being energized under load the first time, too late for that now. You should replace the last old one though.

Kohlback was a mfr out of Brazil, I think they are gone now or they were bought up by someone else. You are not likely to get mfrs data on it now. Is there something special about this that it cannot be replaced with something that is more current?

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[waross]

Look at this old thread,
New motor blowing fuses
thread237-123401

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[larry5000]

Thank You for the responses, my dia was upside down,it works great now. It is a single phase motor. Thank You Guys. Larry

 

[MiketheEngineer]

My cell phone takes pictures - really helpful when putting things back together....