Cliff, I carry #4 also, it's just easier. I'm pro-ufer due to it's ohmic value, but i'm not always called before the pour. All codes aside, more grounding/bonding is better, as are closer/ more direct runs to viable electrodes.
Re: Grounding electrode conductor#78763 10/22/0111:46 AM10/22/0111:46 AM
I also carry number four for GECs. I will go ahead and admit that I don't protect it with conduit. The reason I never use smaller GECs is that they require protection. Number four AWG and larger conductors do not.
I love Ufer grounds but they are seldom available in my work because most of the calls I get are to existing structures.
Whenever the job involves a trench of any length I consider the addition of a bare number two copper grounding electrode to the trench. When I run this with the feeder to an outbuilding I use the separate ground buss connection at the second building even in the absence of other metallic pathways between the buildings. When I connect this conductor to both grounding busses it improves the grounding of both structures. The actual cost is low. The use of a bare number two AWG EGC in place of a smaller size and trenching to the depth required for grounding electrodes instead of just the depth required for the wiring method are the only increased costs. Since that set up is not code recognized as a grounding electrode I have connected ground rods laid in the trench directly to this multi function conductor. In one case I had to run an additional number six GEC between the two panels to satisfy the inspector but when he tried to get me to use insulated wire as the equipment grounding conductor I asked to speak to his boss and his boss overruled him.
The other opportunity I watch for is any chance to tie the grounding electrode system to the well casing. If the well is close by then I just trench to it. If the water line from the well is not back filled yet I run an appropriately sized GEC of number two or larger in the trench. If the inspector does not like it point out that the EGC to the pump motor can be oversized and it must be bonded to the well casing. -- Tom
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison