Footshod
Member
- Location
- Jacksonville Oregon
I have taken the supervisors exam in Oregon and the state is failing me because of my neutral calculations. I know they are wrong and I need as many opinions as possible to build my case. 220.61 states "The maximum unbalanced load shall be the maximum net calculated load between the neutral conductor and any one ungrounded conductor". I was given a 240/120v single phase service supplying primarily 120v loads and a 240v heating load. I totaled my neutral va and divided it by 240. This is a pretty standard method. If you want to get more precise you would balance your 120v loads on A and B phases and which ever one had the slightly larger va would be used for the calculation. This is the method the state used but when the they came up with the va calculated on one phase they still divided it by 240v instead of 120v. I discussed this with the Asst Chief for an hour and a half. He will not pull his head out of the sand and look at the math. The difference in va for sizing the neutral was off by double. Please agree or disagree please and help me pass this test and force the state to reexamine the tests that they are giving. Thanks