phase to neutral loads vs phase to phase
- Thread starter etalaat
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220-volt phase to neutral would be extremely unusual in the US. Are these fixtures manufactured for European electrical systems? I don't know if they will work satisfactorily with the US 220-volt phase to phase system, you may need to contact the manufacturer for clarification and you will definitely need to talk to the AHJ to determine if they will approve them for use on a US system. You will not be able to get 220-volt phase to neutral on a 120/240 or 120/208 3-phase system.
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kingpb
Senior Member
- Location
- SE USA as far as you can go
- Occupation
- Engineer, Registered
To answer your question:
Simply take two of the three phases, feed the line side of an appropriately sized step-up transformer; utilizing a earthed load side that has an output voltage of 220V line to ground.
Simply take two of the three phases, feed the line side of an appropriately sized step-up transformer; utilizing a earthed load side that has an output voltage of 220V line to ground.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
This sounds suspiciously like a high-leg Delta system, and he's looking to use the high-leg to neutral connection; not a good idea.etalaat said:
Etalaat, can you give us more details on the supply and the ballasts?
thunder15j
Member
- Location
- Cali
I was thinking about the possible disadvantages of using the high(power 208volt to ground) leg to drive lighting or even a single phase motor. I have run into that useage on a couple of occasions and it worked fine.
The first problem I see is that most plug-on circuit breakers are not rated at more than 120 volts to ground. The second issue is that this delta connection is usually suppplied by utility provided high voltage transformer configurations that use a smaller transformer to provide the 208 line. That transformer is usually sized only for three phase loads and another larger transformer or transformers is/are sized for three phase motor loads and the standard single phase loads. This loading of the high leg could lead to overloading of that transformer or possible voltage drop.
Of course, I've seen accidental connections (lighting) of 120 volts loads to this high leg and the consequences of that situation should be self explaining. That type of learning experience comes from the school of hard knocks.
The first problem I see is that most plug-on circuit breakers are not rated at more than 120 volts to ground. The second issue is that this delta connection is usually suppplied by utility provided high voltage transformer configurations that use a smaller transformer to provide the 208 line. That transformer is usually sized only for three phase loads and another larger transformer or transformers is/are sized for three phase motor loads and the standard single phase loads. This loading of the high leg could lead to overloading of that transformer or possible voltage drop.
Of course, I've seen accidental connections (lighting) of 120 volts loads to this high leg and the consequences of that situation should be self explaining. That type of learning experience comes from the school of hard knocks.
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