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#28940 - 09/04/03 10:32 PM pressure washer  
rj  Offline
Member
Joined: Jan 2003
Posts: 21
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 11:04 AM Re: pressure washer  
Trumpy  Offline


Member
Joined: Jul 2002
Posts: 8,211
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. [Linked Image]


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#28942 - 09/05/03 11:44 PM Re: pressure washer  
frenchelectrican  Offline
Member
Joined: Feb 2003
Posts: 939
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


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


#28943 - 09/06/03 08:53 PM Re: pressure washer  
Pinemarten  Offline
Member
Joined: Aug 2003
Posts: 123
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?


#28944 - 09/08/03 12:00 AM Re: pressure washer  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
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:

<OL TYPE=A>

[*] 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.
</OL>

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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