WASHING MACHINE THREE PHASE ??

[MRSSPOCK]

Please forgive my ignorance, but am I right to presume that any washing machine motor with a bunch of 5 wires attached, like shown below, is a three phase motor? I've seen folk on Youtube control washing machine motors speed with an inverter, so I am just curious to know, is it as simple as seeing the 5 wires attached, to realise it is a three phase motor. (I realise the other two are for the tacho). Thanks

 

[ScottyUK]

Washing m/c motors can be strange beasts. A few newer - and expensive - designs use inverters, but many others use motors with either multiple windings, or with tapped windings. If there is an inverter then it will be visible somewhere within the machine - probably with a finned heatsink attached. My guess is that yours probably isn't an inverter type unless it says so somewhere on the fascia - marketing folks rarely miss an opportunity to show the advnaced technology within their products.

Best bet is to find the service manual for the type you own.

 

[MRSSPOCK]

Thanks Scotty.

I don't actually have a machine, just this old motor that I want to play around with.

I just got hold of an old inverter but I don't think I will be connecting anything until I get a better idea what's going on.

I noticed on the youtube videos the actual motor stick on badge even said they were three phase.

My one has no mention of three phase.

Thanks

 

[MRSSPOCK]

Once again I'm showing my ignorance, but do three phase motors always have no brushes?

Or another way to put it, if a motor has brushes, (2 brushes), does that mean it can't be a three phase motor?

 

[benta]

The washing machine motors I've seen were universal with tacho feedback.

 

[itsmoked]

All the newer ones are indeed three phase and are run by a VFD. They crank up to around 20,000RPM. They're required as most washers now run back and forth without a transmission and a VFD'd motor can do that all day long. Then when the spin cycle comes along they wind up to insane speeds to drive the drum via the enormous gear ratio dished up by that tiny sheave and the huge drum diameter up to around 850RPM. The speed sense is so they don't have to screw with Field Oriented Control and the price-of-entry needed to support 20kRPM and conversely FOC's iffy/crap performance down around zero RPM which washer motors work around constantly while rotating back and forth.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

Are the brushes to slip rings or to a commutator? Slip rings could indicate a wound field synchronous motor which may indeed be three-phase, although whether that technology is actually used in washing machines I have no idea. A commutator would indicate a single-phase universal motor as suggested by Benta.

 

[waross]

That is more likely a two speed motor.
A three phase motor will have groups of three identical windings, evenly spaced..
A single phase motor will have a set of run windings, often at 90 degree spacing and a second start winding centered midway between the run windings. The start winding is usually a lighter gauge wire than the run winding ans is often recognizable as different than the run winding. A single phase motor will generally have a starting switch and may have capacitors.
There are exceptions to these general comments.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[MRSSPOCK]

So I can be sure it is single phase due to the commutator brushes, which it has.

Thanks for all your replies.

 

[benta]

It was earlier very common to use the Motorola TDA1085C for controlling universal motors in washing machines.

http://pdf1.alldatasheet.com/datasheet-pdf/view/5760/MOTOROLA/TDA1085.html

Check if your motor has a tacho-generator on the other end, it's just a small round thing sitting on the end of the shaft with a couple of wires coming out.

 

[MRSSPOCK]

It has a tacho.

I like the idea of running from 2Hz to 400Hz so I will search for a 3 phase motor.

 

[benta]

Just be aware that a three-phase squirrel cage motor will be larger and heavier than the universal (for the same power output) and have lower starting torque. Depends on your application.

 

[MRSSPOCK]

Ok. Thanks. The load will be virtually zero. There will be a disc mounted with an I value of 0.000028 kg x m² and no ridiculous acceleration will be required.

 

[roydm]

There's a washing machine out of Aotearoa that is very popular as a base for home built hydro plants, it has one moving part no gearbox, the back and forth motion is accomplished by reversing the motor.
I think the spin cycle just switches the number of poles
The motor has about 14 sets of poles, 3 phase for sure. You will see them at high end appliance stores F&P

 

[MRSSPOCK]

I'm already sorted for just £12 but thanks.