I am working on providing a price for a church renovation. The plans originally called for a 120/208 volt service. The size was 1200 amps and they only had one patch of egress. The electrical inspector caught this in plan review. They have re done the drawings and sent them back out to bid. They have now changed the service to a 277/480 volt service at 800 amps. They are re-feeding the existing electrical via a transformer. They only have 480 volt RTU loads and re feeding the existing which is also 480 volts. So there is no need for a neutral. Is there anything in the code that would allow me to provide an alternate price for a 480 volt service instead of a 277/480 volt service.
480 volt service
- Thread starter Jodonnell
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chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
If the POCO secondary is a wye, I believe the grounded conductor needs to be connected to your service as per 250.24(C).
- Location
- Massachusetts
The NEC would allow a straight three phase service as long as that is what the power company is providing.
curt swartz
Electrical Contractor - San Jose, CA
- Location
- San Jose, CA
- Occupation
- Electrical Contractor
In my area I have never seen a POCO supplied 480 volt transformer that was not grounded. All the ungrounded systems I have seen in industrial establishments have primary services with customer owned distribution transformers.
If you are able to get an ungrounded secondary from the POCO you will be required to install ground detection on the system since you are feeding 480 volt loads. It seems like it world be better to just bring the neutral into the service.
If you are able to get an ungrounded secondary from the POCO you will be required to install ground detection on the system since you are feeding 480 volt loads. It seems like it world be better to just bring the neutral into the service.
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