# Single phase or three phase hook up?



## CoolWill (Jan 5, 2019)

No one can answer this. Get more info or tear it apart and trace everything down, or hook it up and tell the owner to throw the switch.


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## MotoGP1199 (Aug 11, 2014)

Pictures of the labels and the connection points might help us give you some info.


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## splatz (May 23, 2015)

kb1jb1 said:


> There is a diagram inside the machine that shows line voltage connections to be one of three ways. 120 volts single phase on L1 & L2, 200-208 volts single phase on L1 & L2. and 200-208 volts three phase on L1, L2, L3.


That might be all there is to it, but who knows. 



> *Would I be correct to assume* <snip>


Famous last words. In general, I won't do that, you have to CYA. 

The *customer* is on the hook to provide you with the necessary information. You don't have a contract with the supplier. Tell the customer you can't make the connections without the necessary info. Alternately, if they can't get their hands on it, they can provide you with an explicit, specific disclaimer in writing and you'll roll the dice for them.


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## gpop (May 14, 2018)

Normally you would expect to find a wiring diagram on the back of one of the panels but even then i would be more interested in opening the cd and printing the manual or going online and finding a manual.

Only listing the amps once does not make sense and would send up a red flag.


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## kb1jb1 (Nov 11, 2017)

CoolWill said:


> No one can answer this. Get more info or tear it apart and trace everything down, or hook it up and tell the owner to throw the switch.


The supplier is coming today to throw the switch. I told him my concerns.


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## canbug (Dec 31, 2015)

I know you can hook up some welders that way and the welder will auto config what you have supplied.


Tim.


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## Navyguy (Mar 15, 2010)

I agree, it might work on both, but I suspect you must make some sort of "jumper" configuration for one or the other. Think of it like Delta - Wye connection in a peckerhead. This is just a guess, but if you are just changing the windings on the motor, I would think that the characteristics (current, torque, inrush, etc) will change also.

Then again, there may be a VFD in there too... who knows.

Cheers
John


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## just the cowboy (Sep 4, 2013)

My thoughts are it does have a VFD in it, but they sized it for single phase input. They give you the option to run 3 phase in to it that will allow the VFD to run better. Some VFD's tell you to wire L1-L2 Single phase or L1-L2-L3 three phase, derating the drive at single phase. BUT that would be on a 208-240 volt 3 phase drive, I've never seen a 120 volt drive do that.


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## micromind (Aug 11, 2007)

There's a good chance that the motor and controls are DC and the power supply will autoswitch to any of the voltages listed. 

As noted, a lot of welders are this way, they'll accept anything from 208 single phase to 600 3Ø and autoswitch for the voltage supplied. 

If it were me, I'd use 208 3Ø mainly because it's easier on the power supply to have all 3 phases present. I would be a bit leery of 120 for the same reason.


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## kb1jb1 (Nov 11, 2017)

Thank you to all. They turned the equipment on today and the machines worked. I wired everything three phase as per what I was initially told. Somebody told me that they just put generic stickers on the machines in order to get through customs. ???


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