Dennis so when there is a 3 or 4 wire service or panel how many hots is it being fed with? I thought a 4 wire was 3 hots and a neutral..... or better yet when you have a 3 phase/3 wire panel and the feeder feeding it reads 3 # 3/0 in a 2 1/2" conduit how do you interpret that?
Even if there is some standard as to how to properly say it, it is not followed consistantly enough throughout the industry.
Example: 120/208 3ph 4 wire - most would assume is 3 phases and a neutral (and it is assumed you always need an equipment ground if on load side of service equipment so there may be a 5th assumed conductor.
Example 208 3 ph 4 wire - most would assume there is no neutral load since the 120 was not mentioned so three phases and an equipment ground.
Example 120/240 3 wire - probably single phase with neutral - equipment ground is needed if on load side of service so 4th wire is assumed.
Example 120/240 3 wire non grounding - kind of the designation for the 3 wire range receptacles where the neutral was allowed to perform equipment grounding also.
You really need to pay attention to other details to hopefully clarify what is needed. If you have a description of loads supplied and there is neutral needed by certain loads you can then figure you need how ever many necessary phases plus the neutral and equipment ground for that load.
