AC Motor Wiring - Page 1
Forum section: electronics / general

author: electronwaster
author_rank: Regular Contributor
timestamp: June 06, 2012, 12:51:21 pm
content: Hi,I hope this question is electronics related enough to belong here.I picked up an old motor from the tip-shop, looks like it's from a washing machine, and hopefully it's an AC induction type. There was no capacitor, and I can see no brushes.There are two boxes on the end, one looks like a DPDT centrifugal switch, the other is as yet unidentified, and has 2 terminals.There are 6 white wires which go to some kind of loom, numbered 2 through 7, 5 coloured wires too: Red, Blue, Red/White, Blue/White, Yellow/White.There will presumably be a common, a run winding, and maybe 2+ windings for 2+ different speeds. This explains 4 of the wires, so I have some extra.Attached is a schematic/diagram of sorts showing the switch and the connections, with all resistances as measured between all possible pairs.I haven't tried connecting anything up yet, I want to be reasonably sure I understand it first before I either let the magic smoke out or the thing explodes in my face- So - any ideas which wires could be which?Thanks,electronwasterEdit: And of course if a photo would help, I will take one and upload it here. I can see no name/model/other markings on the motor other than the numbered leads.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: June 06, 2012, 02:36:36 pm
content: Whatever you do, do it on a circuit with RCD protection.I don't suppose you have a variac or maybe a hefty AC step down transformer.Or you could try running it in series with something so that the current is limited.As long as the circuit is fused/protected properly it wont blow up in your face.Would one of the windings be a starting coil, to give direction?

author: electronwaster
author_rank: Regular Contributor
timestamp: June 06, 2012, 09:35:30 pm
content: Hi there,Yes - I have access access to an RCD powerboard. No variac or large step down transformer, but a large variac is on the wish list.I had thought about using this as an excuse to build a light-bulb test fixture. If I could find an RCD holder, I could put together an all in one device.I'm sure one of the windings will be a start, and that there will be at least one run winding, maybe two or three. Other than that, not too sure. I've seen reference to built in tacho-leads to prevent overspeed, and could any of these extras be for reverse rotation?Cheers,electronwaster

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: June 07, 2012, 01:54:41 am
content: I really don't know the wiring of these old washing machines, sorry I cant help.There must be some old circuit diagrams of such on the web.I also don't know how they managed the backwards and forwards.Another thing that is safe you may be able to measure to give you a clue is the inductance at 50hz.It does seem a lot of effort for an old motor.If you just want to run it as a forward motor you could always just turn it on one winding at a time.Use something in series if you can.

author: jh15
author_rank: Frequent Contributor
timestamp: June 07, 2012, 02:45:19 am
content: Might be switched 2 pole and 4 pole windings for two speeds. Normal and delicate.

author: G7PSK
author_rank: Super Contributor
timestamp: June 07, 2012, 08:58:30 am
content: Forward and back will be done with two different start winding's which might well have a common. The other's will be speed.

author: siliconmix
author_rank: Frequent Contributor
timestamp: June 07, 2012, 09:18:26 am
content: Quote from: jh15 on June 07, 2012, 02:45:19 am"Normal and delicate" ha ha