Louisiana Emergency Generators

Merry Christmas

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
The only other possibility I can think of is that the ground rod has contacted an underground water pipe or other metal object that's connected to the neutral somewhere. This could provide a parallel path for neutral current and therefore allow a larger current to flow through the ground rod. It's not a likely situation but it's still possible.
I was thinking the same thing, but like you, I think it would be a very remote possibility. Maybe an underground fuel storage tank?
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Would very wet and possibly salt infused ground reduce the impedance and make it a more likely scenario?
 

superdave02

Member
Location
South East
Occupation
Electrical Consultant
After 25 days in the field I am home! So, The Army Corps of Engineers completes the site assessments and then we get assigned the work order. Basically these temporary power generators are placed on the ground, THHN is placed on the ground and ran to a connection point. This point could be a disconnect, a meter base, or inside to buss bars in larger gear. The facilities of course are already have a bonded ground/neutral and so does the generator. So, when a ground rod is installed at the generator sometimes we get partial voltage on the grounding electrode conductor. Yes one solution would be to remove the building ground/neutral bond but that is really not feasible since the installation crew is not the de-install crew months later. The manufacturer says to install a ground rod at the generator but what if we simply did not install that ground rod? Any suggestions for these temporary generator installations?
One last note. Sometimes the engineers will direct us to connect the grounding electrode conductor from the generator to the existing ground rod and I know that that is not the correct installation.
 

dkidd

Senior Member
Location
here
Occupation
PE
After 25 days in the field I am home! So, The Army Corps of Engineers completes the site assessments and then we get assigned the work order. Basically these temporary power generators are placed on the ground, THHN is placed on the ground and ran to a connection point. This point could be a disconnect, a meter base, or inside to buss bars in larger gear. The facilities of course are already have a bonded ground/neutral and so does the generator. So, when a ground rod is installed at the generator sometimes we get partial voltage on the grounding electrode conductor. Yes one solution would be to remove the building ground/neutral bond but that is really not feasible since the installation crew is not the de-install crew months later. The manufacturer says to install a ground rod at the generator but what if we simply did not install that ground rod? Any suggestions for these temporary generator installations?
One last note. Sometimes the engineers will direct us to connect the grounding electrode conductor from the generator to the existing ground rod and I know that that is not the correct installation.
Remove the neutral to ground bond in the generator. A ground rod at the generator should be tied to the facility grounding electrode system.
 

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
After 25 days in the field I am home! So, The Army Corps of Engineers completes the site assessments and then we get assigned the work order. Basically these temporary power generators are placed on the ground, THHN is placed on the ground and ran to a connection point. This point could be a disconnect, a meter base, or inside to buss bars in larger gear. The facilities of course are already have a bonded ground/neutral and so does the generator. So, when a ground rod is installed at the generator sometimes we get partial voltage on the grounding electrode conductor. Yes one solution would be to remove the building ground/neutral bond but that is really not feasible since the installation crew is not the de-install crew months later. The manufacturer says to install a ground rod at the generator but what if we simply did not install that ground rod? Any suggestions for these temporary generator installations?
One last note. Sometimes the engineers will direct us to connect the grounding electrode conductor from the generator to the existing ground rod and I know that that is not the correct installation.
Your using THHN? We never use THHN for a temporary generator. It is always welder type cable furnished by the customer or the rental company.
 
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