grounding electrode conductor / supply side bonding jumper

Status
Not open for further replies.
X

xguard

Senior Member
Location
Baton Rouge, LA
My question is: Can a grounding electrode conductor also be used as a supply side bonding jumper?

The scenario: Service Disconnect inside a small metal building. On the outside wall direclty the otherside of the service disconnect is a service pullbox. A very short peice of conduit connects the two through the corrugated wall. Service entrace conductors along with the grounding electrode conductor pass through the short conduit. The grounding electrode conductor is connected to conduit lugs in the pull box and contiues out the box to two ground rods.

I had intended for a supply side bonding jumper to bond the conduit fittings in the box and have a separate grounding electrode conductor exit from the service disconnect, through the wall below the pull box to the ground rods.

Hopefully there is a photo attached.

Also noted, the grounding electorde conductor is not bonded on both ends to the small conduit that exits the box and goes down to the ground rods.
 

Attachments

  • GEC_SBJ_MH.JPG
    GEC_SBJ_MH.JPG
    28 KB · Views: 4
Last edited:
Assuming the conduit is metallic and not flexible, it can be the supply side bonding jumper. You would also be permitted to bond the grounded service conductor to the box.
 
xguard said:
My question is: Can a grounding electrode conductor also be used as a supply side bonding jumper?

The scenario: Service Disconnect inside a small metal building. On the outside wall direclty the otherside of the service disconnect is a service pullbox. A very short peice of conduit connects the two through the corrugated wall. Service entrace conductors along with the grounding electrode conductor pass through the short conduit. The grounding electrode conductor is connected to conduit lugs in the pull box and contiues out the box to two ground rods.

I had intended for a supply side bonding jumper to bond the conduit fittings in the box and have a separate grounding electrode conductor exit from the service disconnect, through the wall below the pull box to the ground rods.

Hopefully there is a photo attached.

Also noted, the grounding electorde conductor is not bonded on both ends to the small conduit that exits the box and goes down to the ground rods.
Click to expand...

Assuming it is of proper size it is fine as the others mentioned. I do note that the enclosure is not bonded per 250.92. That supply side bonding jumper needs to land on the enclosure as well.
 
texie said:
Assuming it is of proper size it is fine as the others mentioned. I do note that the enclosure is not bonded per 250.92. That supply side bonding jumper needs to land on the enclosure as well.
Click to expand...

Also the spacing of the conduit entries is suspect to meet 314.28 but that would not bother me as much as the enclosure not bonded correctly.
 
xguard said:
Service entrace conductors along with the grounding electrode conductor pass through the short conduit.
Click to expand...

The cable that exits at the bottom LHS of the enclosure and into a conduit – is it the said GEC? I don’t see this GEC passes through the short conduit as described. Am I missing something here?
 
Thanks, I see it maked a round loop to each race way's lug and then entered the race way in the middle of the enclosure, then assuming it connected to the service entrance grounded conductor behind the wall.

I see it might not compliant as GEC for lightning current carrying conductor due to its high impedance path for the purpose. Consider lightning hits the overhead service conductors. We want the grounded neutral conductor to carry the current and continues to the low impedance GEC and to ground electrode. However in this case the lightning current must pass through the short conduit where all the load conductors also pass through very close. Right here is the issue: lightning current sees a high impedance GEC (too many Sharpe bends by the loop), and it sees a narrow gap for easy jumping from service conductor to load conductors. The goal of GEC is to quickly move the energy to the earth before it can jump to the load conductors and cause damage. If it were me I would connect GEC to the neutral conductor right up on the service mast, or inside the pull box and keeping the GEC in short and straight line as possible.
 
Status
Not open for further replies.
Top