3 phase motor.. domestic 3 pin..
Discussion
I have been given an electric 250kg hoist.. fantastic.
saw that it had no plug but didnt give it a second thought as it was free.
I now see that it has 3 Live and one Earth wire... Doh'! !
ive been googling for a little while on how to bodge together somethnig that will enable me to run it from my domestic supply, but nothing coherent so far.
is it worth the effort or should i just go out and spend £150 ish on a normal mechanical hoist from clarke or something like that ?
saw that it had no plug but didnt give it a second thought as it was free.
I now see that it has 3 Live and one Earth wire... Doh'! !
ive been googling for a little while on how to bodge together somethnig that will enable me to run it from my domestic supply, but nothing coherent so far.
is it worth the effort or should i just go out and spend £150 ish on a normal mechanical hoist from clarke or something like that ?
Mandat said:
Umless you have a three phase supply, you're not going to get it to work.
You should tell these people that 
http://www.boost-energy.com/phase-converters
NO need to spend that much - in principle running a modest 3ph motor off a 1ph supply is as simple as using the right size motor-run cap from the one phase you can connect to a second (which one you connect to only determines the rotation direction). The motor itself won't care about the missing third phase, it falls out due to the maths. No you wont get full power, but it will likely be close enough for most purposes.
Google more widely for schematics.
Google more widely for schematics.
0.2kW from 1.9A, 3-phase?
That doesn't seem right at the usual 415v (line-line) supply voltage in this country.
Power = root 3 * Vline * Iline * power factor
Root 3 is about 1.73, Vline = 415v, Iline = 1.9A, power factor typically 0.8 for induction motors...
so I'd expect more like 1.16kW.
In any case, to run it "properly" (i.e. at its full rated output) would need a phase converter,either electronic or an old-school motor-generator set. Both are expensive. Buggering about with capacitors might just get it to run but it won't produce anything like it's rated power.
Might be worth digging in the terminal box though, as some motors do have the facility to be connected either as 3 or single-phase.
Otherwise I'd go with an equivalently-sized single-phase motor, funded of course by ebaying the 3-phase one!
That doesn't seem right at the usual 415v (line-line) supply voltage in this country.
Power = root 3 * Vline * Iline * power factor
Root 3 is about 1.73, Vline = 415v, Iline = 1.9A, power factor typically 0.8 for induction motors...
so I'd expect more like 1.16kW.
In any case, to run it "properly" (i.e. at its full rated output) would need a phase converter,either electronic or an old-school motor-generator set. Both are expensive. Buggering about with capacitors might just get it to run but it won't produce anything like it's rated power.
Might be worth digging in the terminal box though, as some motors do have the facility to be connected either as 3 or single-phase.
Otherwise I'd go with an equivalently-sized single-phase motor, funded of course by ebaying the 3-phase one!
One of these is what you need to get it running; dead simple and not expensive.
Actually scratch that; it's worthless, I'll do you a favour and take it off your hands for free.
Actually scratch that; it's worthless, I'll do you a favour and take it off your hands for free.
Edited by hidetheelephants on Thursday 12th July 00:00
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