3.7 K.W. single phase motors

[desmo11225]

Hi All
As I said earlier, I'm a metal man really [Welding] but in retirement have enjoyed helping a young carpenter/joiner, he is moving to a new workshop [Buying it] but there is no 3 Phase.
He has 2 saws a Startrite Tilt Arbour Panel Saw and a Powerful Bench Saw with a 7.5 H.P motor 3 Phase, we have been looking at a couple of 3.7K.W. 3000 RPM 5 HP Single Phase motors, would these be suitable to run these saws ????????
We have looked at Converters/ Inverters and putting 3 Phase into the new workshop but it's too expensive just now[ All spare cash going on new buildings].
Any advice and experiences would be very helpful
. Thank You All in advance
desmo11225

 

[MARK.B.]

No expert here by any means, but a 3.7kw motor giving 5hp should be plenty powerfull enough for most things, maybe require bigger if he is planning some seriously big stuff.

 

[Andy RV]

Has he looked at the price of 5hp single phase motors, you won't get much change out of £700 with both motors and associated starters, he might as well make the leap and get a proper converter.

 

[desmo11225]

Thank You Mark b and Andy RV
The 3.7 K.W. 5 H.P. 3000 R.P.M motors are £197.80 From MM Engerneering, these look to be the best ones, thats each of course plus I think £ 12.50 postage, there are cheaper motors but they are 4 H.P and 3H.P 2800 R.P.M and 2700 R.P.M from £ 162.00 to £ 119.00 respectively.
That's between £ 400 odd to £300 odd the pair, that's the attraction!!!!! but will they do the job gent's???????
Thank's once again for replies
desm11225

 

[Andy RV]

Don't see why they won't work, the bigger saw won't have the same power as before but a 5hp motor will still have some guts. You'll probably have to knock up some mounting adapter plates and might need to machine the pulleys if the shaft is a different size.

 

[The Bear]

Out of interest, what sort of amp do these draw?

Mark

 

[Myfordman]

Out of interest, what sort of amp do these draw?

Mark

The OP should ensure that the electrical installation in the workshop will be man enough to start such a huge motor.
I can see starting currents being 40 or more amps and worse in cold weather.
An upgrade may be needed and type c breakers fitted with the lower earth impedance that these will require.
Consulting a electrician who has motor expertise would be my first step before spending out on motors.
Alternatively, an inverter will give a gentle start and possibly run on your existing supply.

 

[Andy RV]

I've got a 3kw motor on a type c 25amp breaker which is ok so a 32a type c would probably do it.