Building steel as coductor to interconnect

[newguy]

Hey all, Art. 250 specifically states that a metallic water line (W/I 5' of entering building unless it is industrial or commercial application) can be used as a conductor to interconnect the parts a grounding system. Otherwise it cannot be used for the purpose of interconnecting. It states this under Art. 250.52, grounding electrodes, but does not state this under "grounding electrode conductors" section. It does not state, one way or the other, whether or not building steel can be used the same way. Since it does not say that you cannot use it for this purpose, does this mean that you can hit the steel from your main panel and then jump off your steel and hit the incomming water line within 5' of it's entrance to use it as an electrode too?

 

[bphgravity]

Yes. All present electrodes must be bonded together without a suitable GEC or bonding jumper. There is nothing in the NEC that prohibits "Interconnecting" at the water pipe?

 

[newguy]

Thanks for the reply. I know I can interconnect at the waterline but can I hit the building steel first then,at a different spot on the steel, jump off and hit the water? My inspector wants me to hit the water first and then jump off the water to hit the steel. His reason is that his interpretation of the code says that the water can be used to interconnect the electrodes, and it does not say that the steel can be used to interconnect. IMHO the code does not say that I can't hit the steel first and then the water. On this job the water is far from the service and I have steel right at the service location.

 

[infinity]

You can connect to any convenient electrode first as long as the bonding jumpers between the electrodes are properly sized according to 250.66. For example you could go to the CCE first and then go to the water pipe. However in this scenario the conductor would be required to be sized according to 250.66.

250.64(F) To Electrode(s). A grounding electrode conductor shall be permitted to be run to any convenient grounding electrode available in the grounding electrode system, or to one or more grounding electrode(s) individually, or to the aluminum or copper busbar as permitted in 250.64(C). The grounding electrode conductor shall be sized for the largest grounding electrode conductor required among all the electrodes connected to it.

 

[don_resqcapt19]

The question is if you can use the building steel at the GEC between grounding electrodes. The code answer is yes. You can bond between the service equipment and the structrual building steel at one point in the building and then make a bonding connection between the building steel and the water pipe at a different location.
Don

 

[LarryFine]

Right again. The point is that each link in this chain of conductors and electrodes must not be smaller than that required for each electrode downstream (away from the service) of that link.

For example, to use #6cu for a driven rod, it must be the last electrode in the chain, or pathway.

 

[infinity]

Right again. The point is that each link in this chain of conductors and electrodes must not be smaller than that required for each electrode downstream (away from the service) of that link.

For example, to use #6cu for a driven rod, it must be the last electrode in the chain, or pathway.

Unless of course your service is 150 amps or less.

 

[LarryFine]

Unless of course your service is 150 amps or less.

Well, yeah.

 

[newguy]

Thanks everyone who answered. Looks like I can do it the way I was going to install it. Which one of you wants to explain it to my inspector?

 

[al hildenbrand]

Which one of you wants to explain it to my inspector?

Your fee, for the answers above, is to come back and report how you explained it to your AHJ.

 

[infinity]

Thanks everyone who answered. Looks like I can do it the way I was going to install it. Which one of you wants to explain it to my inspector?

Make a copy of 250.64(F) and hand it to him.