- Location
- Massachusetts
I've never known about this. Thank you for letting me know.
Always check the local power company requirements but I know some here in MA have that limitation.
Any of the 4,000 amp services I have worked on where supplied with tens sets of 600 copper.
I find 600 is no worse to work with than 500, might even be a bit easier as the standing if finer. (500=37 strands of 2.95mm, 600=61 strands of 2.52mm) Neither is easy to work with so either way it's going to be a tough day.
The companies I have worked for since the 1990s have used a lot of 600, it is convenient as it provides a true 400 amps per set while 500s do not. Typically people use 500s and count on 240.4(B)s allowance to use a larger breaker ........ even when it does not apply. It is not unusual for me to find a 1,200 or 1,600 amp service with parallel sets of 500 and that is a violation.
I have never done a busway service but it looks to me like the OPs service would be a good candidate for a busway.