On Jul 8, 8:00*pm, George wrote:
On Jul 8, 12:53*pm, NT wrote:



On Jul 8, 11:53*am, Fredxx wrote:

On 08/07/2011 11:32, George wrote:

Hi there, * I have been given what looks like a very useful single
phase motor. 1 1/8 inch shaft. *It is capacitor start, seems to be OK,
but it is taking 9 amps running light. *It is also getting warm and
does not sound "happy".

The capacitor is fine, but what is likely to be wrong, *that's about 3
Hp, isn't it?

Any comments welcome. *Thanks George.

I would say you have a failed winding, probably why you were given it..

If it is a true capacitor start, the fact it starts turning by itself
suggest that side is OK.

9 Amps maybe reactive current, but should sound smooth with a slow
pulsing 100Hz note. *At most it should get luke warm with no load.

If it turns out to be a shorted winding, you can always run it in
series with a 3kW non-fan heater. Performance is affected a fair bit
with a 2.2kw device, but it often makes it runnable.

Bearing trouble is easy to spot, if it wont turn easily or squeals.

NT- Hide quoted text -

- Show quoted text -

No there is no bearing problem, I think I shall have to take it
apart, *It makes a sort of buzzing noise when it is running at full
speed, although it runs up to speed immediately, so the start
capacitor is doing it's job, but if it has a speed switch then it
could have shorted. *It was just given to me by a neighbour who was
leaving and turned out a lot of junk, some of it is good stuff, so I
can hardly complain.

If it does have shorted windings, how much it is likely to cost to
have repaired, I have a very nice compressor that is crying out for a
3 HP motor like this? * I ran it via a device I still have called a
Somar Powerboss, which saves power used by a motor by reducing the
voltage untill the speed starts to drop and then saves power by
keeping it running at the lowest voltage possible to maintain revs.
It hunted between 200and about 170v but the current varied between 6
and about 4 amps when it shot up to 6 I don't really know what this
indicates though as I cannot find the handbook for the Powerboss up to
now.

Cheers George.

This is a great way to kill your powerboss. Dont use it on the motor
till the latter is fixed. 9A will be the average current, the current
when it hits the partially shorted wind will be many times this.
You're lucky it survived, typically the triac dies immedaitely.


NT