If I'm using 4/0 Al, I can use #4 Cu, right?
I didn't know if the "rod, pipe or plate" part in 250.66(A) let me use #6 or not, 250.52(A)(1) Doesn't specify size...
250.53(C) points to 250.66, but I guess I'm caught up in whether it is considered a "pipe" electrode...
Remember, I have to tear out and replace something that most don't bother doing in the first place here... So, is #4 Cu OK, or do I have to use #2???
The #6 will get yanked but now I don't know whether to buy #4 or #2 Cu to replace it.
If I have to use #2, please show me how to arrive at the answer for future reference.