T i m wrote:
Hi all,

I've been given one of those big chrome floor standing 3 speed fans to
look at because it doesn't run. It was given to my mate (not running)
so I don't have any information beyond that.

When you power it up you can hear/ feel the thing 'humming' slightly,
suggesting it is receiving power yet the fan doesn't spin on any of
the speeds, even when the fan blade is given a little push (either
way). The fan blades are very free to move and the fan looks pretty
new (so I'm not ruling out a d.o.a.).

I think it's wired up like this:

http://waterheatertimer.org/images/M...citor1-800.jpg

(except it's not a 'start' cap / winding but 'run' on these motors
isn't it)?

Measuring ohms from neutral (basically across the L/N on the mains
plug) I get:

219 Ohms on speed 3, 375 on speed 2, 393 on speed 1 (slowest) and
infinity with it off (of course). ;-)

Measuring between the 3 wires coming out of the motor to the switch I
get: N-S3 = 219, S3-S2 = 157 and S2-S1 = 46 ohms (so doesn't quite
add up correctly (422 v 393)?

There is also a run (?) cap of 2uF that tests out on my DMM (as 2uF)
(and open circuit on the ohms test) and a run winding that measures
375 ohm. Measuring the voltage across the cap with it on speed 1 gives
206V (does that sound right)?

I can't see any thermal trips so apart from the cap breaking down
under load (I have one on order just in case) or it being wired up
incorrectly (within the motor, can't get at much in there without
cutting it open) I can't see what the cause of it not running is?

Any thoughts or ideas please?

Cheers, T i m


These normally use a shaded pole motor. The rule of thumb for feed
current via a capacitor is 80mA per uF. So you should have a maximum
current below this. measure the current with a moving coli meter.IME if
after stripping the motor and soaking the sintered bushes in an
oil/parafin mix then reassembling, you are looking for a duff connection
somewhere as your resistance reading seem reasonable. Good luck.