480 vs. 208-volt service
480 vs. 208-volt service
(OP)
I had a construction manager for a client get all bent out of shape because I suggested a 208-volt service for a couple of buildings for a project on which I was working. We were only in the schematic design phase for the project but based on what I knew, we did not need a 480-volt service for the buildings. One building was a hospice (elderly care) facility of about 18,000 square feet and the other an admininstration building of about 22,000 square feet (two story). I still haven't been able to talk to the construction manager but apparently he thinks practically all commercial buildings require a 480-volt service. He also may have been involved in similar projects for which the engineers showed a 480-volt service.
In my opinion too many engineers fall in love with having 480-volt services designed for buildings on projects with which they are involved. A big reason is flexibility I think. They want to be ready for all possible loads and the voltages required. But they are having the owners pay a premium for the flexibility unnecessarily I think. What are your cut off points for 480-volt vs. 208-volt services?
In my opinion too many engineers fall in love with having 480-volt services designed for buildings on projects with which they are involved. A big reason is flexibility I think. They want to be ready for all possible loads and the voltages required. But they are having the owners pay a premium for the flexibility unnecessarily I think. What are your cut off points for 480-volt vs. 208-volt services?






RE: 480 vs. 208-volt service
The lighting load for the office building is going to less than a 100 amps and you can't use 277 lighting in the residence bldg.
The 480 volt service will require step-down transformers to run receptacles, lighting, etc.
I usually start such projects with a reference from one of the Means books that show 8va/ SqFt for an office building and 9-10Va/ SqFt for a retirement home/ extended care facilliy. They are a good ball park figure and never wind up far from there.
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
The serving utility company may have criteria as to the service voltage requirements based on load.
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
I think arc flash analysis is a simpler process at 120/208, whenever Ifault is below 10kA anyway.
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
RE: 480 vs. 208-volt service
Your should do your due diligence explaining why 208V might be preferred including the 'transformer garden' aspects then do as the customer/customer's agent wants.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com