Carultch
Senior Member
- Location
- Massachusetts
I think this opens the door to violations from the inspector. you have to follow the current code your jurisdiction follows, not the latest NEC. If i do something that the latest NEC permits, but wasn't part of the 2008 NEC, I will get screwed with a violation and a potential change order that the client would have to pay extra for. guess who gets yelled at?! Me.
What happens if products cease to exist, that were once required by previous code cycles?
As an example, in NEC 2017, they introduced the concept of "functionally grounded systems", that most systems would've been since GFCI was required. This applies to both grounded systems on transformered inverters that are grounded through a GFCI device, and ungrounded systems that are "functionally grounded" by being non-isolated from a grounded AC grid. I like the new term, but I don't like that it applies to two fundamentally different kinds of systems. I'd prefer functionally grounded as the first kind I described, and to continue to call the second kind of system ungrounded, as we did prior to 2017. My suggested term for the second kind of system, would be symmetry grounded, since the two polarity voltages are symmetric about ground.
In any case, NEC2017 now specifies that functionally grounded systems of either kind, require disconnecting means on both polarities, and OCPD only on one polarity. This means a 2017-compliant combiner would have disconnect poles on both polarities, a group of fuses on the positive, and a simple busbar on the negative. If pre-2017 combiners cease to be in production, you couldn't build it this way and comply with pre-2017 codes, that required you NOT to disconnect the grounded polarity.