On Jul 8, 9:23*pm, NT wrote:
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 -

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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- Hide quoted text -

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I take your point. I have probably been lucky! This morning I
dismantled it and inside it is like new. No sign of overheating. No
sign of any wire or centrifugal switch on the rotor either, it is a -
squirrel cage, I think it is called and is a composite construction of
alluminium and iron set on the shaft with nothing but the two
bearings. There is only the rotor, the capacitor and the field
stator. It was made by EFACEC of Portugal IEC 34-1 Model BF 5C
100L 44 50Hz 240v 2.2 Kw 14a 1400 /min. There does not look much
can be wrong with it.

The only thing that looks at all untoward is a very slight marking in
the rotor and the stampings on the stator that indicates that a tiny
bit of contact has occurred. I have cleaned the whole thing up inside
and I think I shall take the body to my local friendly rewind shop for
a professional opinion, he may have a growler, if such things still
exist, maybe there is something better now. This will have to wait
till Monday now, but I am tempted to actually try it on load, Is an
indicated current of 9 amps actually excessive? It is obviously not
getting very hot, if it is out of phase with the voltage, the actual
wattage generated could be quite low? Why should the powerboss hunt
between two voltages though, showing a much lower current when in
circuit, too?

Regards George.