Bonding Jumper Size

[shortcircuit2]

When metalic raceway, such as EMT is used for protection of a 3/0 bonding jumper to the buildings structural metal, what is the required size of the jumper for the raceway?

shortcircuit2

 

[augie47]

Re: Bonding Jumper Size

From 250.64 (E)

The bonding jumper for a grounding electrode conductor raceway or cable armor shall be the same size as, or larger than, the required enclosed grounding electrode conductor.

 

[shortcircuit2]

Re: Bonding Jumper Size

250.64(E)specifly mentions the Grounding Electrode Conductor.

My GEC connects to the buildings metal water pipe supply. Then there are bonding jumpers to other available electrodes such as the metal structure or bonding of the sprinkler system.

So does the same rule for bonding the raceway for the GEC apply when determining the size of bonding jumpers for metal raceway that protects bonding jumpers to other available electrodes?

shortcircuit2

 

[derf48]

Re: Bonding Jumper Size

IMHO the definition of grounding electrode conductor includes these bonding jumpers between electrodes. By bonding two electrodes together you are connecting a grounding electrode to the grounded conductor.
for example, if you run a GEC to the metal frame of the building next to the service, and at the opposite corner of the structure the water enters, if you choose to run a conductor between metal frame and water at this point, is it a GEC or is it a bonding jumper. This conductor could be very short, maybe 3' or more. There is no doubt that it is bonding two electrodes together. I also believe it is connecting the metal underground water pipe to the grounded conductor and the equipment grounding conductor (per definition 100). Therefore, it is a GEC and must follow all sections that apply.

Fred

 

[eprice]

Re: Bonding Jumper Size

I don't agree that the definition of a grounding electrode conductor includes the bonding jumpers between electrodes. They perform a related function, but are not the same. However, 250.53(C) (2005 NEC) requires these bonding jumpers to conform to the same 250.64(E) that augie47 cited.

 

[derf48]

Re: Bonding Jumper Size

That section was one of those I know it is in here somewhere, but couldn't find it! Thanks

Fred