I am not a lawyer. I have a PhD in electrical engineering. I also have a severe case of multiple chemical sensitivities. (I am allergic to the world.)
For the last couple of years, I have managed to make a living working at home, by working for the person who was my PhD advisor in college. A lot of what I do is just try to provide some background on the problems that he is dealing with.
I don't have the particular details. I know that there might be some type of problem with how a room air conditioning unit was wired. The building is probably 25 to 30 years old.
I have viewed the current NEMA WD6 standard online, but what I would like to know is -- could the configurations have changed over the years. That is could the current configuration, say for example, for 250V,20A at one time have been the approved configuration for 277V, 20A?
I don't know how to locate older versions of the current NEMA WD6 standard.
I would also like to know if NEC 440.62 on Room Air Conditioners has changed over the years. 440.62(2), 2005ed, says that a room ac unit cannot be more than 40A and 250V,single phase. I would like to know if that provision changed, and 277V used to be allowed (and when it changed).
Any information would be appreciated.
