ECN Forum Forums Code Related Discussion NEC & other Code issues PEX and copper bonding

250.104(A)(1) has nothing to do with "other metal piping". That requirement is found in 250.104(B).

George, I guess the right size ground would be #12 if the circuit likely to energize the pipes is the bathroom lighting or GFCI, and #10 if it was the dryer in the laundry. Kind of a judgement call, is it?

I think because this house has 200A service supplied by 4/0 aluminum that we need a #4 copper that jumps all the water piping and returns to the service ground.

Matt, I think you need to look up the difference between grounding the water piping against becoming accidentally energized and using a metal water pipe feed AS A PART OF YOUR GROUNDING ELECTRODE SYSTEM.

As you can see from my posts, I am no code whiz, but am enjoying the learning process going on here.

With some of the commercial buildings (malls) I am working on it seems like sometimes I can build my whole service in less time than I can figure out and install the proper grounding---sprinkler, water, bldg steel---which may involve running to the high up steel above, getting out thru the masonry to grd rods, etc.

Poorboy, 250.104(A)(1) refers to table 250.66 for sizing the bonding jumper; because this is water piping, 250.104(A)(1) is the only section that applies.

So in my earlier reference to the multiple occupancy retirement building, according to 250.104(A)(2) I would use #8 copper (as per table 250.122) because the sub panels in the apts. were 100A. Am I getting any smarter at all?