Service Bonding with Outside Transformer

Status
Not open for further replies.

ROKETRIK

Member
Sbj

Sbj

There is no main bonding jumper in the service, I was trying to make the point that there should be one per 250.24, but that by running a grounding conductor with the service lateral a bonding jumper at the transformer and in the service would put that grounding conductor in parallel with the grounded service conductor.

If you look at exhibit 250.7 in the 2011 handbook you see the basic situation, only imagine that the grounding electrode connection is made to a ground ring at the transformer end only. Now imagine that the service lateral is rigid metal conduit with a grounding conductor alongside the grounded conductor. The service lateral brings the neutral and the EGC to the service. Now if you bond the grounded and grounding conductors in the service they are in parallel.

IMHO the grounding conductor in that conduit should only bond the conduit to the service. A ground rod should be driven at the service and a GEC run between the ground rod and the ground bar. The ground bar should be bonded to the neutral bar with a main bonding jumper.
 

Smart $

Esteemed Member
Location
Ohio
There is no main bonding jumper in the service, I was trying to make the point that there should be one per 250.24, but that by running a grounding conductor with the service lateral a bonding jumper at the transformer and in the service would put that grounding conductor in parallel with the grounded service conductor.

If you look at exhibit 250.7 in the 2011 handbook you see the basic situation, only imagine that the grounding electrode connection is made to a ground ring at the transformer end only. Now imagine that the service lateral is rigid metal conduit with a grounding conductor alongside the grounded conductor. The service lateral brings the neutral and the EGC to the service. Now if you bond the grounded and grounding conductors in the service they are in parallel.

IMHO the grounding conductor in that conduit should only bond the conduit to the service. A ground rod should be driven at the service and a GEC run between the ground rod and the ground bar. The ground bar should be bonded to the neutral bar with a main bonding jumper.
Don't have a handbook from any code cycle.

Does the following illustration depict your situation...

grounding3.gif
 
A ground ring.

I wouldn't call it a ground ring:

http://www.vias.org/radioanteng/rae_01_12_04.html (and other sources)
The counterpoise is an insulated net of radial wires assembled above ground to form a large capacitance with the ground.


I know a ground ring as a loop of conductor around a structure connecting multiple grounding electrodes and pieces of equipment (search the forum for "ground ring").
 
Status
Not open for further replies.
Top