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#28940 - 09/04/03 07:32 PM pressure washer
rj Offline
Member

Registered: 01/23/03
Posts: 23
Loc: Skidmore, Missouri, USA
I am probably having a big brain fart on this one, but hear goes. I had a pressure washer that I tried running off of a generator tonight. I would turn the pressure washer on it would run for about 5 seconds and then the motor would stop turning. I have not torn into the pressure washer yet. I was wondering if it was not going to the run windings and shutting off. It is a 120v unit, I used it last year and it worked fine. This is a old washer and it has 3 capacitors. Like I said this is probably a dumb guestion, and I think I am having BIG brain fart. It has been a long day. THanks

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#28941 - 09/05/03 08:04 AM Re: pressure washer
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
rj,
What size generator do you have running the pressure washer?.
Water-blasters (as they are called here) have a huge start up current, hence the large number of capacitors.
But 3 of them?, in a Cap Start, Cap Run motor, there should be 2 capacitors.
All these capacitors do, is improve the power factor of the start and run currents and to a certain extent, lessen the curretnt load through the centrifugal switch on these motors.
_________________________
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#28942 - 09/05/03 08:44 PM Re: pressure washer
frenchelectrican Offline

Member

Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
you have to explain little more clear for the pressure washer and the hp rating and the 3 capatiors useally are set as one very large one for starting and 2 smaller one for running aka captior start and capatior running motor and if keep blowing fuse or stall the generator check the starting swtich and some case the generator can be too small for pressure washer usage bear in mind the motor can start anywhere from 4 to 6 time over running current ( it do apply all motors expect dc type that is diffrent story )

merci marc
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Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


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#28943 - 09/06/03 05:53 PM Re: pressure washer
Pinemarten Offline
Member

Registered: 08/23/03
Posts: 122
Loc: Edmonton, AB, Canada
You could try starting it with the wand open, to lower the pressure and possibly lowering the load on the motor.
It may also be the 'cut-off' pressure is set to high. What does the gauge read when the motor is dropping out?

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#28944 - 09/07/03 09:00 PM Re: pressure washer
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
I'm in favor with Marc's (Frenchelectrician) post.
3 Capacitors would (normally) indicate a Capacitor Start / Capacitor Run type
Induction Motor.
This Motor could very well be intended to be run at 230 VAC 1Ø (but not absolutely!).

Two Capacitors would be in the Start circuit (for a very large starting value), and the third one (also in the aux. circuit)
would be the "Run" Capacitor. The Run Cap would be much smaller than the Start Caps.

Several reasons for the stalling include:



    [*] Frozen / sticky Bearings on the Motor, the Pump, or both,

    [*] Extremely high head pressure,

    [*] Incorrect operating Voltage,

    [*] Voltage too low,

    [*] Genny cannot produce enough locked rotor power,

    [*] Failed Start Capacitor(s) - shorted or open,

    [*] Centrifugal Start Switch is not closed for Start,
    or

    [*] Centrifugal Start Switch is not opening after Starting Sequence has taken place.


An extremely apparent, but maybe overlooked item may be a Polyphase Motor???
Capacitors would be there only for P.F. correction... sounds very unlikely to me... but....

Chances are the problem is a result of sticky bearings, or something similar, which would keep the pump / Motor from rotating freely.
Check the obvious first, then move up towards internal or system troubleshooting.
Start with the simplest stuff first.

If the problem(s) turn out to be internal, check the Capacitors. If you need help on Cap tests, let us know.

Good luck!

Scott35
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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