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Motor Whoes...

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John Hill:
Darren,  single phase capacitor start motors will run in either direction and in fact you can usually make a uni-directional one reversable if you know what you are doing.

The way they work is that there are two wirings, the 'run' winding which gets full mains voltage through it and the 'start' winding which is in series with a capacitor.

In other words, thinking of the start winding alone, you have one end of the winding connected to the mains and the other end connects to the capacitor and the other end of the capacitor connects to the other mains lead.  Either the coil end or the capacitor is connected via the 'start' centrifugal switch which opens when the motor is spun up a little.

To reverse such a motor the combination of start winding and capacitor is reversed in the circuit.

Preci: You just connected something wrong.

P.S. Are you sure it is not a one of Bogstandard's left handed or American capacitors? :lol:

Darren:

--- Quote from: John Hill on March 12, 2009, 04:39:11 PM ---

Preci: You just connected something wrong.



--- End quote ---

John, I haven't wired anything apart from a cap, it started going backwards before I even removed that, and with a new one in it's place. The caps are bi-directional so it doesn't matter which way they are connected.

I suspect the little mechanical start unit has failed as there are sparks coming from that area. I.E it's not releasing and taking the cap out of circuit.
Hence the blown cap, not designed to be left powered up, esp at 110V rating on 240V mains.

I've had a look at the start release mech now and it seems all loose and rather suspect. TBH I think it's best to bin the motor and fit another one.

bogstandard:
If you had your wits about you Darren, you would get that heap of an engine running and do it mechanically. I used to work with a small holding chap that ran his old big miller from the power takeoff on his tractor. Even the mechanical power feeds worked. Noisy, but it got the job done.

Bogs

John Hill:
Well Darren  I agree it sure seems like the centrifugal switch is pukaru which is a mechanical problem.

If you cant fix the switch you could use a push button as a 'starter', arrange it so that the start winding and the capacitor is only in circuit while the button is pressed.  Then to start the motor press and hold the button then turn on the power, let the button go when it has spun up.

[As always, take care with electricity]

Darren:

--- Quote from: bogstandard on March 12, 2009, 05:30:26 PM ---If you had your wits about you Darren, you would get that heap of an engine running and do it mechanically. I used to work with a small holding chap that ran his old big miller from the power takeoff on his tractor. Even the mechanical power feeds worked. Noisy, but it got the job done.

Bogs

--- End quote ---

My car's not that bad John, ok it's not new I'll grant you......

BTW, I picked up one of those free running/fixed pulleys recently....so ya never know what may happen in that little shed yet... :ddb:

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