I just looked at a house with a 200 amp 1-Ø service. The contractor installed a #4 solid copper conductor to the rebar in the foundation. He attached the conductor to the rebar with an acorn clamp (listed for use on 5/8" ground rod.) He then attached another #4 solid copper conductor to the rebar under the same clamp and connected it to the copper water pipe. I believe this installation is in violation of the NEC as the ground wire should be continous. I also think the connection to the rebar should be an exothermic weld (Cadweld). What do you think?
The grounding electrode conductor (GEC) has to be continuous to any available electrode. From that point the GEC stops and a connection to any other electrode is a bonding jumper. The connection to the rebar is OK if the acorn clamp is listed for direct burial/rebar/concrete encasement.
But two conductors under one clamp is most likely a violation of 110.3(B) While a cadweld connection may be desirable, Burndy would like you to know they make a compression connection they belive is superior. Whatever is used must be listed for the application.