So I have this older neighbor that blew two capacitors on this old motor. One starter capacitor, number 1 and one running capcitor, number 3 on the sheet. The running capacitor blew the whole top open and the start capacitor blew at the relief hole. Does the wiring look correct? The motor turns a little but struggles to get going. No luck finding a wiring diagram and I'm not sure on this capacitor wiring.
220v 7.5 hp single phase motor capicitor wiring problem
- Thread starter toolman4
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micromind
Well-known member
I agree. The 15uF capacitors need to be on parallel and in series with the start winding.
The 260s also need to be in parallel and in series with the start winding and also in series with the start switch.
What are the lead numbers?
I wouldn't guarantee that the start capacitors need to be in parallel. Using 110 volt capacitors in series is fairly common.
Baldor doesn't do that today. And 260uf would be pretty low value for capacitors in series.
I wondered about that. They should be in parallel correct? The pole with 2 wires on #3 , one of those to the pole on the other side correct?. The arrows are just the wires going to a specific pole not direction of flow. What about up top? #1 should also be parallel, one of those wires to the other side? There is 4 wires on capacitor 4 ...will have to see where that is hooked. New diagram maybe little more directional. Power comes in through the overload and heads up to the motor.
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micromind
Well-known member
On a 7 1/2HP motor, if there are 4 leads, the 2 larger ones are the run winding, the 2 smaller ones are the start winding. If that's the case, write back and I'll explain how to hook it up but I need to leave now.
There are others here who can tell you how to hook it as well.
There are others here who can tell you how to hook it as well.
BillK
Well-known member
Is there a data plate on the motor ? That would help a lot. Or even a part number ?
That other wire on number 4 goes back to the motor. No data plate and no part number. It's blue and someone said it looked like a balder but don't know for sure. Originally used as a silo unloader for silage. There is a nice aluminum plate on the top reminding you to grease the bearings ...nice and easy to read.
BillK
Well-known member
Has he actually had this motor running recently and it just failed ? Or is it something he got and is trying to get running ?
TRWham
Well-known member
When applied on 240 V capacitors need to be rated 370 V or better. If they are connected in series, the voltage on each cap is reduced, so the rating could be lower but the capacitance of the combination will also be lower. They will see ~340 V peak to peak.
Was this motor running previously?