Tumble dryer induction motor questions

[threedee]

I came upon treasure trove of old(but modern) electric motors pulled out of washing machines and tumble dryers.

Brought one of each, WM being 17000rpm brushed and more interesting to me tumble dryer motor which is induction type.

Questions are as follows
1. Why it wont start on its own ? I have to spin it by hand to get it to run. Any direction i spin it goes. Cap is on.

2. 3 wires go into motor. If i run ground and wire 1 it starts quick and runs pulling ~80W, if i connect gnd and wire 2 it starts slow but consumes 130-140W. Speed seems the same, both wires need manual start... Explain please.

3. Main question - how to make it start by switch flip and no turning by hand ?

 

[AdrianUK]

I think the problem here is that you've only got a part of the chain....

When these motors are fitted into the appliance as designed there is almost certainly a control PCB or some other electronics between them & the mains - those motors aren't intended or designed to connect straight onto the mains.

 

[threedee]

You are talking washing machine motors, those have to have wpm board.
They can be run directly, bypassing speed controller but at suicide motor mode only (series wound). Which will eventually overspeed and splatter itself all over the place...

 

[bernardgreen]

You don't connect ground to power any motor, you use Neutral and Live.

One of the windings needs to be connected to Live via a capacitor such that the current and thus magnetic flux is about 90 degrees out of phase with the other winding which is connected directly to Live.

With two windings slightly out of phase the magnetic flux is sort of rotating so the rotor gets pulled into rotary motion.

If the cap(acitor) is "on" then is it connected ? It may that the capacitor is defective and no longer providing the out of phase current to the winding.

The last tumble drier I saw in use had different speeds depending on on material and also reversed from time to time. So if you have a motor from a sophisticated tumble drier then it will require a controller.

 

[ericmark]

Washing machine and tumble driers now often use three phase motors the three phase being generated from the inverter drive.

It is possible the motor is not 230 volt or 50 Hz you need to know what is in the washing machine to drive it.