# How to find out if single phase or 3 phase?



## ogoa (Feb 5, 2012)

I am looking to purchase a machine which requires 230 volt 3 phase power. I am not sure if my building has 3 phase and that much voltage.

I contacted the person selling the machine and he told me that I most likely may have 120 volt single phase if it's not an industrial building...

How do I know if I have 3 phase and 230 volt? 

Thanks!!


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## Julius793 (Dec 13, 2011)

this is in your house, business? call your power company and ask, i wouldnt suggest opening your panel to find out


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## plummen (Jan 10, 2010)

If its in a commercial building how many wires are coming to the mast above your meter socket,are they marked with differant colors like black/red/blue or maybe brown /orange/yellow?
Those would be common signs of 3 phase wiring,there might also be a seperate service for your single phase 120/240 loads depending on how they do things in your area


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## wareagle (Apr 11, 2011)

If your service is 3 wires it is single phase. If it is 4 wires its three phase.
For voltage look at your meter. It may say 208 or 240 volts. I would still check with the utillity.


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## Julius793 (Dec 13, 2011)

wareagle said:


> If your service is 3 wires it is single phase. If it is 4 wires its three phase.
> For voltage look at your meter. It may say 208 or 240 volts. I would still check with the utillity.


what if its a delta?


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## ogoa (Feb 5, 2012)

Julius793 said:


> this is in your house, business? call your power company and ask, i wouldnt suggest opening your panel to find out


It's a commercial building. What should I be looking for within the panel? 



plummen said:


> If its in a commercial building how many wires are coming to the mast above your meter socket,are they marked with differant colors like black/red/blue or maybe brown /orange/yellow?
> Those would be common signs of 3 phase wiring,there might also be a seperate service for your single phase 120/240 loads depending on how they do things in your area


Alright... I will check on this when I go back there on Monday.

Thanks...


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## ogoa (Feb 5, 2012)

wareagle said:


> If your service is 3 wires it is single phase. If it is 4 wires its three phase.
> For voltage look at your meter. It may say 208 or 240 volts. I would still check with the utillity.


I looked at the meter and it says 120 vA...

I am still confused and yea I will have to contact the utility company and probably ask just to verify...

thanks


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## micromind (Mar 9, 2008)

Just because the power co. supplies the service with 3ø doesn't mean there's 3ø available in the building. 

The only way to know is to remove the panel cover and check voltages across the busses. 

A lot of commercial buildings around here have 3ø services and 3ø meters, but only single phase panels. 

Rob


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## joecaption (Nov 30, 2011)

It would be rare to not have 220 volts coming into the the top of the panel so if your panel has 220 volts, with a Static or dynamic phase converter you could run a 3 phase machine with only single phase power coming in.
The static ones are cheap to buy but you loose a lot of HP and are prone to failure.
With A dynamic one it's possible if you buy one with more HP then the highest HP you will be using to use it to start more then one machine as long as you only start one at a time.
One of the many places that sell these is MSC.com
There's even plans on line on how to build one if your into eletronics.


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## joecaption (Nov 30, 2011)

http://www.phaseconverter.com/


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