2 Ground Rods - Discussion

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infinity

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New Jersey
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IMO if they're not connected together with a bonding jumper then no. What do you think?
 

kwired

Electron manager
Location
NE Nebraska
I have no problem with it from a theory perspective, I'd guess most will say it is not in compliance with NEC unless you prove the one at the service is 25 ohms or less.
 

infinity

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I have no problem with it from a theory perspective, I'd guess most will say it is not in compliance with NEC unless you prove the one at the service is 25 ohms or less.

I was thinking the same, a single rod unless proven to be 25 Ω or less is not considered a grounding electrode.
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
IMO, it is legal as the equipment grounding conductor could be used as grounding electrode conductor if it is sized properly and of a wire type.

250.121 Use of Equipment Grounding Conductors. An equipment
grounding conductor shall not be used as a grounding
electrode conductor.
Exception: A wire-type equipment grounding conductor installed in
compliance with 250.6(A) and the applicable requirements for both the
equipment grounding conductor and the grounding electrode conductor
in Parts II, III, and VI of this article shall be permitted to serve as both
an equipment grounding conductor and a grounding electrode conductor.
 

jxofaltrds

Inspector Mike®
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Mike P. Columbus Ohio
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ESI, PI, RBO
IMO, it is legal as the equipment grounding conductor could be used as grounding electrode conductor if it is sized properly and of a wire type.

I'm liking the answers. Part time I do inspections on these homes. Often homeowners are doing the wiring. I am always looking for a code compliant way to help them (pass) on their installations.

Other inspectors require 4 ground rods and 2 even on a temporary for a new build.
 

tom baker

First Chief Moderator
Staff member
Yes but using the EGC as a GEC requires bonding bushings on any metallic conduits. plus the extra loops add impedance see note to
250(A)(1), there is a section on use of the EGC as GEC...the GEC has to be unspliced, so not sure how it would work to use the EGC
 

david

Senior Member
Location
Pennsylvania
Simple question. Is this code compliant?

If no, please explain why you would fail me.


You are attempting to extend the direct connection required between the service neutral and the grounding electrode conductor at the manufactured home



To use the busbar as a busbar type main bonding jumper in the manufactured dwelling as others have said you would need a main bonding jumper of the wire type, bonding the busbar in the service panel and the busbar in the manufactured home together
 

Dennis Alwon

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Location
Chapel Hill, NC
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Yes but using the EGC as a GEC requires bonding bushings on any metallic conduits. plus the extra loops add impedance see note to
250(A)(1), there is a section on use of the EGC as GEC...the GEC has to be unspliced, so not sure how it would work to use the EGC

If I have 2 rods at a service and connect both to the busbar of the panel wouldn't that be compliant
 

102 Inspector

Senior Member
Location
N/E Indiana
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Inspector- All facets
2 rods on a temporary pole would be standard around my area. If the temporary pole constitutes a service, then grounding needs to meet the requirements of 250. If someone is injured, then you would have to explain why the second rod was not provided or when the test was observed for 25 ohms or less. Rods and bonding jumpers are cheap at that point.
 

stevenje

Senior Member
Location
Yachats Oregon
2 rods on a temporary pole would be standard around my area. If the temporary pole constitutes a service, then grounding needs to meet the requirements of 250. If someone is injured, then you would have to explain why the second rod was not provided or when the test was observed for 25 ohms or less. Rods and bonding jumpers are cheap at that point.
How would an injury occur with just one ground rod to a temporary service? It would be interesting to see if there has been any studies done on injuries that have occured by just installing one ground rod for temporary services.
 

bkludecke

Senior Member
Location
Big Bear Lake, CA
Occupation
Retired Electrical Contractor
An attorney doesn't need to demonstrate that improper grounding caused an injury. The way it works is, the attorney convinces a jury that the contractor obviously was not properly trained, incompetent, greedy, or evil by not complying with one code rule so he/she obviously had no regard for any of the other rules. The contractor's credibility and competence is destroyed and the jury has its villain. This is done routinely in civil and criminal court cases.
 

augie47

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Location
Tennessee
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State Electrical Inspector (Retired)
An attorney doesn't need to demonstrate that improper grounding caused an injury. The way it works is, the attorney convinces a jury that the contractor obviously was not properly trained, incompetent, greedy, or evil by not complying with one code rule so he/she obviously had no regard for any of the other rules. The contractor's credibility and competence is destroyed and the jury has its villain. This is done routinely in civil and criminal court cases.
Spot on !!! I've seen that happen more than once in legal disputes. One, unrelated Code violation, means the entire job is non-compliant :)
 

stevenje

Senior Member
Location
Yachats Oregon
An attorney doesn't need to demonstrate that improper grounding caused an injury. The way it works is, the attorney convinces a jury that the contractor obviously was not properly trained, incompetent, greedy, or evil by not complying with one code rule so he/she obviously had no regard for any of the other rules. The contractor's credibility and competence is destroyed and the jury has its villain. This is done routinely in civil and criminal court cases.
I am in total agreement with the legal ramifications of not being code compliant. For the sake of discussion, how would an injury occur with just one ground rod to a temporary service and does anybody know of any documented injuries from this type of installation?
 

bkludecke

Senior Member
Location
Big Bear Lake, CA
Occupation
Retired Electrical Contractor
Service grounding is service grounding regardless of whether the service is temporary or permanent. The reasons for the grounding of a service are not to prevent injuries to workers or others but rather to "limit the voltage imposed by lightning, line surges, or unintended contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation." So the same question could be asked about grounding any service. In the area where we work the building departments only require a single ground rod on a temporary service pole but for a number of other reasons such as practicality, available space on small lots, trip hazards...........
 
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