Source of shaded pole induction motors?

[Andrew Gabriel]

Can anyone suggest a supplier for a replacement shaded pole induction motor? This is for a kitchen extract (not a hob extract) in a flat. The air outlet is linked to the building's exhaust system, and it looks to have been a very expensive "nuaire" extractor in its day, and worth repairing if I can. (Nuaire still exist, but don't do this model anymore, or anything which looks as robust.)

The motor is one of the largest shaded pole motors I've seen, probably

60 - 100W (rating plate says 0.65A starting, 0.5A running). Motor has a pair of mounting studs on the drive shaft end about 47mm apart, and a 6mm drive shaft which needs to extend at least 65mm from the mounting studs (this one is actaully 70mm), with clockwise rotation looking at the drive shaft.

Was hoping to find a stockist where you could enter details of the motor specification and it would come up with a match or two. My google foo is not finding anyone with a range of shaded pole motors though.

This one, the winding has shorted out, so I'm presuming that's effectively unrepairable?

[Bob Minchin]

I've not seen shaded pole motors available as standard parts in the same way as other types of fractional horsepower motors.

Being such a high power motor (for a shaded pole that is), the winding should use relatively thick wire and be a darn sight easier to re-wind than a low power one. Measure the diameter of the wire as accurately as possible. measure the cross section of the would section of the bobbin and calculate the number of turns a) assuming the best packing factor and b) assuming the wire to be square. The correct number of turns will be somewhere in the middle of the two numbers. Rewind the coil with the same gauge of wire (or a little thicker having checked that the bobbin will hold all the turns still) It will be the number of turns rather than the correct DC resistance that it is important to maintain.

Good Luck

Bob

[meow2222]

hand winding never packs as densely

Does replacement need to be shaded pole?

NT

[Andrew Gabriel]

Not particulary, although it may be harder to find something else which matches the mounting, shaft length, etc. It's currently two speed (just switches in a giant power resistor in series), but that's probably not very important.

[harry]

This type of motor is very inefficient even if you can get a spare. Newer fans have permanent magnet motors and use about half the electricity. So if you run it for long periods well worth dumping and getting an up to date replacement. Also the fan will be aerodynamically more efficient and likely quieter to boot.

[Brian Gaff]

Assuming on can get the main frame apart to get the bobbin off. Some of these seem to be held together very very well! Brian

[Andrew Gabriel]

The coil has been resin impregnated with a cloth cover, and has flex emerging from it, so no chance of seeing the windings. Actually, the whole stator has been resin-dipped (probably under vacuum) up to the hole for the armature. I've never worked out how these things are assembled anyway, in terms of getting the laminated stampings threaded through the bobbin. Unlike transformer E/I stampings, the stator stampings don't seem to have breaks in them anywhere to enable assembly.

Bearings are gone too, and although those are probably replacable, it devalues trying to repair this particular motor, as every working part of it is knackered.

It's part of a centrifugal blower made by Smiths Industries. I was about to say there's no name on the motor, but on closer inspection, it says Mycalex Motors Cirencester. Can find some references to this company, but none which indicate it still exists.

[F Murtz]

the best way to find the turns is to cut the coil through and remove it,then burn all the insulation off then you can count the turns

[Bob Minchin]

Yebbut there will be a hell of a lot and calculation will get you close enough. I guess the OP will want to keep the bobbin too.

[Andy Bartlett]

Give Remco a call. I have had them make up a couple of specials over the years for the fan unit in my ageing solid fuel boiler. They may well have a standard replacement if you have the part details.

Andy

[Andrew Gabriel]

Oh, magic -- if I mix and match between their standard motors, I can get an exact match, so I've pinged off an email to them to ask if they can make one up.

[Andrew Gabriel]

Ordered a custom specification motor on Wednesday late afternoon, and it arrived on Friday morning. Fantastic service.

[Rick Hughes]

Why not take it to electrical rewind shop and ask for a quote ?

[ian]

@ Andy Bartlett:-

Awesome call - I had a very old Myson Hi-level convector heater which the m otor died on last night. I just need to keep it going this winter till we h ave a new kitchen next year. It had a Mycalex induction motor in it. After reading this thread - I emailed Remco and they had a like for like, in term s of dimensions, replacement. THANKS!

Ian