Author Topic: Static to Rotary  (Read 1745 times)

Offline slowcoach

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Static to Rotary
« on: November 04, 2015, 08:25:03 AM »
Hi all!

Might be a stupid question this, but is it at all possible to convert a static (uk 240v to 415v) 3 phase converter to a rotary converter using a 3ph slave motor?

Cheers
Rob  :thumbup:

Offline John Rudd

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Re: Static to Rotary
« Reply #1 on: November 04, 2015, 10:28:18 AM »
I would say so.....but DaveA is the expert on here, he's building one right now as I write... :zap:
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Offline David Jupp

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Re: Static to Rotary
« Reply #2 on: November 04, 2015, 12:01:56 PM »
A slave motor doesn't strictly convert it to a rotary converter, but it will improve the quality of the 3 phase.  The slave motor (being unloaded) starts easily and once rotating it generates the ghost phase.  I keep meaning to get around to something similar in my shop, as it is in cold weather I have to start the pump for the hydraulic press before trying to start the power hacksaw.

Offline DavidA

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Re: Static to Rotary
« Reply #3 on: November 04, 2015, 01:52:44 PM »
 I think the word 'expert' is a bit premature.  I've only done this once, but my system does work as I expected.

Getting back to the question.

I'm not sure just what you (Slowcoach) mean here.
It would appear that you have already done the conversion to three phase with the static convertor.

As David Jupp states, using an unloaded three phase motor will assist in the start up of any other motors slaved to it. I.e. essentially they are just connected in parallel.

The beauty of using the idler motor in the method I use seems to be that you pick a motor that is a higher horse power than any others you are going to connect to it.  Then you select your artificial phase capacitor to match this motor. You wont need to use separate capacitors for the other motors.  You could then plug in any other motors providing that they are smaller than the idler.
Essentially you have created your own three phase supply for the workshop.

Andrew Wildman has a much more professional set up than me. He may be the person to give better advice.

Dave.

Offline slowcoach

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Re: Static to Rotary
« Reply #4 on: November 11, 2015, 08:11:42 AM »
Thanks guys, but I've ditched the static and got myself a digital inverter, save me having to change belts  :ddb:

Rob  :thumbup: