3 phase power in a 1 phase shop.?

COLTIMPALA

COLTIMPALA

Yo homie... is that my briefcase?
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Ok, so I'm looking to buy a larger metal lathe, but can only find 3 phase units. How difficult is it to convert this somehow to use in a shop where I only have single phase? Is this a big deal?
 
In all honestly I'd look Into trying to find a lathe in single phase 240v otherwise you'd be looking into running phase converters which can lead to high $$. Another thing to keep In mind whatever you plan on having installed make sure your service can handle the additional load. I'd be happy to run a load calculation for you.
 
I can't help but wonder if it'd be easier to just ditch the 3 phase motor and replace with a SP with similar parameters. Chap, I don't have a specific lathe picked out at the moment to run those numbers.
 
COLTIMPALA said:
I can't help but wonder if it'd be easier to just ditch the 3 phase motor and replace with a SP with similar parameters. Chap, I don't have a specific lathe picked out at the moment to run those numbers.
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Just need specs on your current home.
Sq foot
Range kw/amp
Dw kw/amp
Micro wave kw/amp
Disposal kw/amp
Garage door kw/amp
Water heater kw/amp
Ac maximum breakers
Heat breaker size
Well pump?
 
Chap0 said:
Dang I haven't honestly looked into them for a bit. Working up north in a machine shop we were installing units that were specd out for well over 2k per unit.
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2KW or $2k?
 
You have multiple options for creating 3 phase from single phase. These include.
1 VFD (as mentioned above). You need to purchase one sized for your lathe motor.
2. Rotary phase converter. You can build your own for around $500 plus a suitable hp 3 phase donor motor. Or you can buy new / used. If you plan on obtaining multiple pieces of 3 phase equipment, an RPC powering a 3 phase load center isn’t a bad option. A kit for a smaller RPC (5-7 hp) may cost less than $500.
3. Static phase converter. Inexpensive, but you won’t develop full hp for your lathe.
4. Phase Perfect system. Very expensive, but the cleanest power.
5. 3 phase generator

I‘m personally using 1, 2, and 5.
 
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Just get a rotary converter and be done. VFDs are nice but kinda machine specific. Wire a rotary to a 3phase panel and when you add another piece of equipment all you need to do is wire directly to that panel. That is about the best option I've found.

* I have a mill and converter on here forsale on here if you interested PM me*
 
So excuse my ignorance; let's assume the lathe has a 3 phase motor that spins at, idk, 1200rpm which then turns a belt which turns the lathe. Couldn't I just junk the 3 phase and replace with a single phase 220v motor of similar specs?
 
That is a possible option but in my experience it is hard to match th HP rating and size requirements. This depends alot on how the lathe is built. For example I have one that lathe that has a 7.5 hp motor. Lathe is only a 15/50 size machine. Trying to find a replacement with the correct shaft size, HP and frame size would probably be next to impossible.
 
COLTIMPALA said:
So excuse my ignorance; let's assume the lathe has a 3 phase motor that spins at, idk, 1200rpm which then turns a belt which turns the lathe. Couldn't I just junk the 3 phase and replace with a single phase 220v motor of similar specs?
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You could but you need to spec out a SP motor with about 25% more HP to get the result you're looking for. Then you'll need to verify your 220v circuit can handle the extra amps.

I have a really nice, very expensive Ingersoll rand air compressor with a bad 5hp 3ph motor, got the compressor for free. A 7.5hp 220v SP motor was going to run about $600 and it was likely going to blow the 30A breaker every time I turned it on. It was WAAAAY cheaper to keep my eyes peeled for a used 5hp 3ph ($100) then buy a ~$200 VFD.
 
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Ditto the comments above about why not to swap out 3 phase for a single phase motor on your lathe (unless it is a really small lathe).

Plus, if you go for an RPC you are now set up for additional 3 phase equipment. Whether you hard wire it into a load center, or put a 3 phase twist lock plug on the output, it's an investment that can pay future dividends.
 
Go with a phase converter instead of changing out to a single phase motor...

We use Phase-a-Matic Rotary phase converters with great success on our CNC equipment that does not have internal phasing capabilities.
We also use a Phase-a-Matic Static converter for the Bridgeport Mill and it works fine.
 
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