I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.

I forgot to mention that I live in the UK and my supply is 220/240. and
the pump is a 220/380v 50hz 1hp 075kw and 5.3amps

On 25 Jan 2006 05:57:54 -0800, wrote:

I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.

get a single phase motor/pump.

seriously.

You can build or buy a static phase converter, but you'll lose
a lot of power and that's probably not ideal for a water pump.
A rotary phase converter is another alternative -- again, you
can buy one, or make one from an old 3 phase 220 v motor, capacitors,
and some switches and relays. The motor, which will be used as a
rotary transformer, must be rated at twice the horsepower of the
one you're driving.

There are also electronic inverters for variable frequency drive
that can supply three phases from one. Again, they should be
derated 50%.

These are all available on Ebay, or from US suppliers like
McMaster Carr, Enco, etc. I'm sure they're available in the
UK as well.

wrote:
I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.

wrote:
I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.



Look on ebay for a VFD, I've seen them used on several drill presses
with 3 phase motors running off a single phase supply.

Connect two of the three phase wires coming from the motor directly to the
mains. The third wire will be connected to one of the other lines via a
capacitor. The line it's connected to determines the direction of the
rotation.
The capacitor value must change depending on the conditions.
During the starting (2 to 5 sec; max) a 30 to 100 µF 265 Vac capacitor will
do the job.
As soon as the motor reaches its nominal load and speed, 1.5 to 5 µF 330 Vac
is enough. The big capacitor must be disconnected.

I've a grinder wired like that which has been working for years.

Several old washing machines were equipped with such capacitors and values.
They were using single phase motors with two windings (lo & hi-speed) with
two capacitors each to be able to start under load. A centrifugal switch was
ensuring the capacitor change.


a écrit dans le message news:
...
I forgot to mention that I live in the UK and my supply is 220/240. and
the pump is a 220/380v 50hz 1hp 075kw and 5.3amps

On 25 Jan 2006 05:57:54 -0800, wrote:

I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.


There is no "cheap" way to do it, although you can get a device that
will generate a three phase output from a single phase supply. It is
basically an intelligent three phase inverter system. They work well
but are not overly cheap.
You might find it cheaper to buy a single phase water pump.


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Two capacitors are enough. see my early post on the topic.
One for starting, one for continuous use.
Not perfect, of course but cheap and painless for a motor

The Shar Par a écrit dans le message news:
...
On 25 Jan 2006 05:57:54 -0800, wrote:

I want to use a 3 phase water pump from a single phase domestic supply.
What would be the cheapest way to go about this.


There is no "cheap" way to do it, although you can get a device that
will generate a three phase output from a single phase supply. It is
basically an intelligent three phase inverter system. They work well
but are not overly cheap.
You might find it cheaper to buy a single phase water pump.


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News==----
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That may be fine for a table saw but you'll lose an awful lot
of power and the pump may not have adequate capacity for that.

frischmoutt wrote:
Two capacitors are enough. see my early post on the topic.
One for starting, one for continuous use.
Not perfect, of course but cheap and painless for a motor

Correct !
But the trade off is quickly done. In most occasions, rewinding the motor is
worthless as well as buying an inverter.


"Mike Berger" a écrit dans le message news:
...
That may be fine for a table saw but you'll lose an awful lot
of power and the pump may not have adequate capacity for that.

frischmoutt wrote:
Two capacitors are enough. see my early post on the topic.
One for starting, one for continuous use.
Not perfect, of course but cheap and painless for a motor