Re: LOAD CALCULATIONS FOR 120/240, 3 PHASE DELTA SERVICE???
c10, I was beginning to think no one answered your question. But looks like rbalex and the niffty picture gave you the same answer as I came up with. Being in the utility industry I use a lot of open delta for buck/boost to get 600 down to 480. I have never heard the terms kicker and lighter. And charlie came through for you very well on calculating load. I was just going to say the simple answer that 3 phase power (VA not watts) is square root of 3 times phase to phase voltage times amps. Also bear in mind as most of the replies said that there are requirements that the equipment be tested/listed for open delta, corner grounded delta, buck boost, etc. Under certain fault conditions your single pole 120 rated breaker will get 208 to interrupt. Also you 120 volt equipment may not have been UL tested for 208 safe leakage current. In a 3 phase delta system you can tie one leg to ground with no problem. That second one usually lets out a lot of smoke. Its less risky to use a wye system but it is also less risky to use a full or over sized neutral instead of earth as we do. Anyway it sounds like your apartment complex is near an industrial complex. Talk with your utility folks about your load needs.
c10, I was beginning to think no one answered your question. But looks like rbalex and the niffty picture gave you the same answer as I came up with. Being in the utility industry I use a lot of open delta for buck/boost to get 600 down to 480. I have never heard the terms kicker and lighter. And charlie came through for you very well on calculating load. I was just going to say the simple answer that 3 phase power (VA not watts) is square root of 3 times phase to phase voltage times amps. Also bear in mind as most of the replies said that there are requirements that the equipment be tested/listed for open delta, corner grounded delta, buck boost, etc. Under certain fault conditions your single pole 120 rated breaker will get 208 to interrupt. Also you 120 volt equipment may not have been UL tested for 208 safe leakage current. In a 3 phase delta system you can tie one leg to ground with no problem. That second one usually lets out a lot of smoke. Its less risky to use a wye system but it is also less risky to use a full or over sized neutral instead of earth as we do. Anyway it sounds like your apartment complex is near an industrial complex. Talk with your utility folks about your load needs.
