[Cartierusm]

So I'm getting a Mori Seiki SL1 1978 CNC Lathe. I'm not sure how much power it actually needs.

On the machine the badge is very vague so maybe one of you electrical genius' can help me, please.

All it says is 3PH 3 Wire 220V 27KVA 60hz.

I find it hard to believe something with 2 axis', a 2HP Hydraulic Pump and a 5HP spindle will need 70+ amps of 220 3PH.

I have 100 amps 220 Single phase at my shop and I'm hoping that will work.

Any help is appreciated.

[Cartierusm]

OK turns out I have 240VAC single phase, if that makes any difference.

[Cartierusm]

So I'm starting to think I can use a static phase converter because the whole system is DC, aside from the hydraulic pump which I'm going to use a VFD for. So using a phase converter to feed the large transformers inside might work.

[underthetire]

First, if your using a phase converter, why bother with a VFD on the hydro unit? Still have a 3phase coolant pump as well. Those old DC power supplies on the drives I'm pretty sure used 3 phase power as well, but it's been years since I looked at one. And 240 is pretty high, especially once you get a phase converter.

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[Cartierusm]

Thanks, I figured out that there are multiple taps on the transformer (remember I'm going from research as I don't have the lathe yet) from 208 to 240.

So do you think I should just use a static phase converter if all the power is converted via transformers to DC???

[underthetire]

I'd get a good one with filtering, the cheapo buzz box type can create havoc with old controls like that, especially since most of the capacitors on that are at end of life cycle.

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[Cartierusm]

Cool. Thanks. Any specific brand that's like that? I take it Phase-A-Matic is no good?

[underthetire]

All I remember the phase a matic being a buzz box with dirty voltage. There are some modern alternatives.
Phase Technologies - A world leader in low harmonic and phase converting technologies

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[Cartierusm]

Thanks. Yes Phase Perfect make digital phase converters, but they are expensive. They quoted me $4500.

[Cartierusm]

So can I run a 220V machine on 240V? The transformers it seems have 240V taps, but I'm not sure how to wire them.

It's a Yaskawa transformer. On the top it has 4 set of taps, they reads: U1 with a 0 below it, U2 with a 20 below it, V2 with a 200 below it, V1 with 240 below it. A wire labeled U2 is hooked up the Tap labeled U1 and a wire labeled V1 is hooked up to the tap V2.

I know this machine was run at the machinery company on 208.

How would I and can I change the taps to run it on 240V and what does the labels on the taps mean?

I can post pics if someone needs them.

[sin_arms]

What you need is a 3phase rotary phase converter and one for that size you would need a 60hp one (phase converters will run a cnc at half the power their motor is 60hp=30hp usable). American Rotary makes a great one and you will probably spend $4-6k on one.

For the transformer that can take multiple voltage inputs (208v, 220v,240v, etc) and you will have to determine what your output voltage from your phase converter is to set your transformer jumpers. I'm pretty positive it is a 3phase only transformer.

[Cartierusm]

Yeah i figured it out. Still didn't make the machine work. I'm starting my retrofit.