strawserde
New member
Is there a recommended limit for utilization of single phase power for a single load? Specifically, this would be the power level at which transition to a three phase power source is recommended.
Maximum single phase loading
- Thread starter strawserde
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hurk27
Senior Member
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- Portage, Indiana NEC: 2008
Re: Maximum single phase loading
I think it is more like 7.5 HP as you can nolonger buy motors over 7.5 HP that are single phase. At least around here. or air conditioning equipment more than 5 tons will be 3-phase. try to find a single phase air-compresser that is (true) 10 hp we couldn't.
As far as supplyed power we can get services even up to 1200 amps single phase and maybe larger. I have seen a 1600 amp service on a apartment building around here.
[ November 20, 2003, 07:27 PM: Message edited by: hurk27 ]
I think it is more like 7.5 HP as you can nolonger buy motors over 7.5 HP that are single phase. At least around here. or air conditioning equipment more than 5 tons will be 3-phase. try to find a single phase air-compresser that is (true) 10 hp we couldn't.
As far as supplyed power we can get services even up to 1200 amps single phase and maybe larger. I have seen a 1600 amp service on a apartment building around here.
[ November 20, 2003, 07:27 PM: Message edited by: hurk27 ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Maximum single phase loading
One of the problems going to 3-phase is our POCO will only install 120/208 or 240 delta. this presents problems with many 240v or 230v motors as there are a few that won't run on 208 volts we have had this problem come up many times. we had eneginer's request a 120/208 volt system then order equipment from a supplyer who don't have a 230v or 240v motor that will run on 208 without over heating. then the blame war goes on. who should of told who. when it was the eneginer that should of known. So always check what is availble for the equipment that you are going to install before settling on what type of service you need.
One of the problems going to 3-phase is our POCO will only install 120/208 or 240 delta. this presents problems with many 240v or 230v motors as there are a few that won't run on 208 volts we have had this problem come up many times. we had eneginer's request a 120/208 volt system then order equipment from a supplyer who don't have a 230v or 240v motor that will run on 208 without over heating. then the blame war goes on. who should of told who. when it was the eneginer that should of known. So always check what is availble for the equipment that you are going to install before settling on what type of service you need.
Re: Maximum single phase loading
Hurk27,
there are larger single phase motors, e.g. fromPrecise Power, or you could use a VFD.
Then there are really large medium voltage single phase motors. I'll let you figure out who the user might be...
Hint: The motors are on the move most of the time.
[ November 21, 2003, 12:24 PM: Message edited by: c-h ]
Hurk27,
there are larger single phase motors, e.g. fromPrecise Power, or you could use a VFD.
Then there are really large medium voltage single phase motors. I'll let you figure out who the user might be...
Hint: The motors are on the move most of the time.[ November 21, 2003, 12:24 PM: Message edited by: c-h ]
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