Motor Help

Steve:

These motors are for use with a triac or thyristor motor controller, and have a couple of fields to give the speed ranges for washing and spinning. Unless you have the controller to go with it, it is a bit restricted on use.

Peter

-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info:

Sounds like a a motor normally driven by a triac speed controller. AB armature, CD field, EF tacho generator. The tacho generator would be a little item mounted round a shaft extension at the commutator end of the motor. It is used to feed back shaft speed to the controller.

Without the controller it is a single high speed series wound commutator motor. This sort of motor can seriously overspeed if run on noload at full mains voltage. It will probably survive this treatment but I do NOT recommend it. Trial run at reduced voltage or with a 100W lamp in series with it.

Jim

Hi Steve,

These are called universal or series motors.

There's only one way to wire the motor: connect the stator & armature in series (hence the name), and apply mains across them; e.g. probably connect A to live, D to neutral, and B to C. To reverse direction, reverse polarity of one coil, e.g. swap A-B. Stop & sniff if nothing happens - the windings can burn out in half a minute if misconnected.

Coil E-F is most likely a tacho generator at one end of the motor shaft, which generates a voltage (proportional to speed) used as feedback for a control circuit. Speed control of universal motors is nearly always done by phase control, using a triac circuit: it's very similar to a domestic light dimmer - you may be able to use one of these at a pinch.

There's one condition: series motors from white goods need speed control or a mechanical load, otherwise they run too fast; hooking up to 240v will make the motor run at full power well past rated speed, eventually destroying the bearings. For brief testing at full voltage, turn off as soon as it starts to scream.

The book "Electric Motors in the Home Workshop" from the Workshop Practice series is full of info for reclaiming motors. There's another one ("Electric Motors"?) that is also handy.

HTH Guy

Peter, Jim, Guy - many thanks for your help - especially the bit about the tacho winding - I never would have guessed!

Steve

---------------------------------------------------------- Steve Randall G8KHW snipped-for-privacy@btinternet.com UKRA #1072 Level 2