Jointer electric problem

[TD]

Jointer tries to start, partially revs up and then breaks the circuit. Any thoughts?

[tiredofspam]

Is it a 220 unit working on 110? or vice versa?

Has it been running before in your shop or is this the first time?

[dpb]

Undersized wiring leading to excess voltage drop and hence high current demand or bad bearings or similar in motor or possibly jointer head. Check (w/ unplugged, of course) that it turns easily by hand w/ no bearing noise, etc., for the latter.

What's the voltage/HP/wiring size/fusing?

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[krw]

If this is a new problem, it could be the centrifugal switch.

[Ecnerwal]

...or, if it used to work, and the mechanical parts check out OK, electrical connection going bad (find & fix it before you have a fire from it.)

[HeyBub]

Centrifugal switch = gizmo on the non-business end of a motor that disengages the start capacitor when sufficient RPMs are reached.

[whit3rd]

That's a motor drawing too much current for the breaker. Either there's other loads on the breaker, or the motor is oversize for that circuit, or maybe the motor or breaker are faulty. Check the motor dataplate for ratings and compare to your breaker size first.

[spaco]

Sounds to me like the starting winding isn't disconnecting.

Pete Stanaitis

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whit3rd wrote:

[Martin Eastburn]

If it is just starting and doesn't move out -

One of two possible conditions:

The start winding has a bad capacitor - open. Common.

The run winding is in parallel and normally a switch is opened when the motor is up to speed - taking out the start winding/cap circuit.

The load on the motor - spindle and knives turning is to much for the 'keep alive' winding that is used to keep it at speed once there. It isn't strong enough to get a loaded system up to speed and draws to much current.

The other possibility is the run cap (if you have one) is shorted and the run winding isn't in circuit, start winding gets it up to speed and switches off. Motor spins down.

Mart> Jointer tries to start, partially revs up and then breaks the circuit. > Any thoughts?

[Josepi]

I would like to fourth the start winding, except it won't be the winding but rather the disconnectin switch, usually centrifigal. Windings don't burn out, usually and if it was a cpacitor it wouldn't start turning well and once up to speed it wouldn't make a difference. Make sure you clean off the WD-40 when you are done loosening it up and lube with a dry lube. Clean contacts well, They make be pitted beyond function but usually can be reshaped for a few months more.