We are bidding a campground and RV site upgrade. Project consists of upgrading the service and reducing the number of pedestals on each circuit. The question that has come up is it required to install two ground rods at each pedestal. The campground does not want to spend the money unless it is a code requirement. I don't believe it would be required unless the AHJ would interpet that the pedestals are separate structures.
Campground and RV site upgrade
- Thread starter ramIII
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102 Inspector
Senior Member
- Location
- N/E Indiana
- Occupation
- Inspector- All facets
My guess is it would depend on how the main disconnect is set up for the pedestal. If there is a disconnect that shuts off the entire circuit feeding the pedestals, then the grounding electrodes should be at that location, not each pedestal. The feeder to each pedestal should have the proper GEC to provide proper grouding provisions. I am sure others smarter than me can give better guidance.
I think you are going to check with your AHJ. Locally a ground rod has not been required, but I can see the validity in requiring one (two). I don't have A 2014 NEC but my draft copy shows pedestals mandated as a structure.(551.75)
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We are still using the 2008 code here in Va. I found an article from a national camper and RV association where they supposedly lobbied to have that interpretation changed. The article stated that although the requirement was not totally dropped it suceeded in getting it delayed another three years which per the date of the article would make it the 2017 code. In the 2008 nec per article 551.76(A) it says that a equipment grounding conductor must be run with the feeders but makes no mention of ground rods being required.
I saw that you were under '08 and, as you noted, there is no definitive clause there, but, with the NEC's loose definition of a structure, I could see the argument.
I mentioned to 2014 ROP only to show that some folks view it that way to suggest you double check with your AHJ. Some of US have weird vision
I mentioned to 2014 ROP only to show that some folks view it that way to suggest you double check with your AHJ. Some of US have weird vision
I saw that you were under '08 and, as you noted, there is no definitive clause there, but, with the NEC's loose definition of a structure, I could see the argument.
I mentioned to 2014 ROP only to show that some folks view it that way to suggest you double check with your AHJ. Some of US have weird vision
Another interesting item I found when researching this is in article 551.76(D) when it refers to article 250.32(B) it mentions separate buildings. It does not say structures. I believe the original intent of the article was for buildings and like structures such as covered shelters etc. The nec definition of structure could mean almost any thing we connect to, as everything has to be built or constructed.
Here is the ROP:
19-79 Log #3385 NEC-P19
Final Action:
Accept
(551.75)
________________________________________________________________
Submitter:
David A. Williams, Delta Township
Recommendation:
Revise text to read as follows:
551.75 Grounding.
All electrical equipment and installations in recreational
vehicle parks shall be grounded as required by Article 250. For the purposes of
this section a RV pedestal shall be considered a separate structure and shall
comply with 250.32.
Substantiation:
This section is often misunderstood by installers and
inspectors stating that a RV pedestal is not a separate structure. In the 2007
ROP cycle there was a proposal to state that a RV pedestal is not a separate
structure. The panel statement in part states:
?The panel agrees with the
Submitter?s conclusion that RV pedestals are to be treated as separate
structures, and, therefore, require grounding electrodes per 250.32. 250.4(A)(1)
provides the reasons for the use of a grounding electrode at each structure.?
The panel and now the submitter are clear that a RV pedestal is considered a
separate structure, but many in the industry are not clear and this change will
ensure that the pedestals are properly grounded.
Panel Meeting Action: Accept
Number Eligible to Vote: 14
Ballot Results:
Affirmative: 14
________________________________________________________________
19-79a Log #CP1905 NEC-P19
Final Action:
Accept
(551.75 Informational Note (NEW))
________________________________________________________________
Submitter:
Code-Making Panel 19,
Recommendation:
Add an Informational Note to read as follows: See
250.32(A) Exception for single branch circuits.
Substantiation:
The informational note was added to provide reference to the
exception in Article 250 and enhance usability.
Panel Meeting Action: Accept
Number Eligible to Vote: 14
Ballot Results:
Affirmative: 14
_________________________________
19-79 Log #3385 NEC-P19
Final Action:
Accept
(551.75)
________________________________________________________________
Submitter:
David A. Williams, Delta Township
Recommendation:
Revise text to read as follows:
551.75 Grounding.
All electrical equipment and installations in recreational
vehicle parks shall be grounded as required by Article 250. For the purposes of
this section a RV pedestal shall be considered a separate structure and shall
comply with 250.32.
Substantiation:
This section is often misunderstood by installers and
inspectors stating that a RV pedestal is not a separate structure. In the 2007
ROP cycle there was a proposal to state that a RV pedestal is not a separate
structure. The panel statement in part states:
?The panel agrees with the
Submitter?s conclusion that RV pedestals are to be treated as separate
structures, and, therefore, require grounding electrodes per 250.32. 250.4(A)(1)
provides the reasons for the use of a grounding electrode at each structure.?
The panel and now the submitter are clear that a RV pedestal is considered a
separate structure, but many in the industry are not clear and this change will
ensure that the pedestals are properly grounded.
Panel Meeting Action: Accept
Number Eligible to Vote: 14
Ballot Results:
Affirmative: 14
________________________________________________________________
19-79a Log #CP1905 NEC-P19
Final Action:
Accept
(551.75 Informational Note (NEW))
________________________________________________________________
Submitter:
Code-Making Panel 19,
Recommendation:
Add an Informational Note to read as follows: See
250.32(A) Exception for single branch circuits.
Substantiation:
The informational note was added to provide reference to the
exception in Article 250 and enhance usability.
Panel Meeting Action: Accept
Number Eligible to Vote: 14
Ballot Results:
Affirmative: 14
_________________________________
Thanks for the info
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
And here is the text from the actual NEC2014
And here is the text from the actual NEC2014
551.75 Grounding. All electrical equipment and installations
in recreational vehicle parks shall be grounded as
required by Article 250.
Informational Note: See 250.32(A), Exception, for single
branch circuits.
from the ROP:
For the purposes of
this section a RV pedestal shall be considered a separate structure and shall
comply with 250.32.
So pedestal did not make it into the text.
250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.
Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non?current-carrying metal
parts of equipment.
And here is the text from the actual NEC2014
551.75 Grounding. All electrical equipment and installations
in recreational vehicle parks shall be grounded as
required by Article 250.
Informational Note: See 250.32(A), Exception, for single
branch circuits.
from the ROP:
For the purposes of
this section a RV pedestal shall be considered a separate structure and shall
comply with 250.32.
So pedestal did not make it into the text.
250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.
Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non?current-carrying metal
parts of equipment.
pjholguin
Senior Member
Just to qualify this installation, this means there is no need to provide a grounding conductor with feeders. Am I correct in my interpretation of this?
PJHolguin
PJHolguin
Just to qualify this installation, this means there is no need to provide a grounding conductor with feeders. Am I correct in my interpretation of this?
PJHolguin
If I understand your question correctly, that is incorrect. An equipment grounding conductor MUST be included with the feeder per 551.76.
The need for an grounding electrode at each pedestal is not as definitive. As noted above, there have been proposals to make one mandatory by clarifying that a pedestal is a separate structure, but from all appearances that call would still be an AHJ decision (unless the requirement made to to the 2014NEC)
AdrianWint
Senior Member
- Location
- Midlands, UK
I know that I'm quoting the rules in a different country here.....
But for our UK equivalent a ground rod IS required at the pedestal & each outlet must be protected by an RCD (GFCI).
The reasoning is to ensure that the ground pin of the outlet (and hence the frame of any RV connected to it) is maintained at the same potential as the earth immediately around it thus reducing the possibility of a person who is standing on the earth but touches the RV chassis being able to receive a shock.
But for our UK equivalent a ground rod IS required at the pedestal & each outlet must be protected by an RCD (GFCI).
The reasoning is to ensure that the ground pin of the outlet (and hence the frame of any RV connected to it) is maintained at the same potential as the earth immediately around it thus reducing the possibility of a person who is standing on the earth but touches the RV chassis being able to receive a shock.
It's my understanding that ground rods do very little for touch potential. An effective equipment grounding conductor properly installed is what reduces the risk of the metal parts becoming energized in the first place.
AdrianWint
Senior Member
- Location
- Midlands, UK
I also agree with that statement. They use of the RCD (GFCI) is provided to provide automatic disconnection in the event of a ground fault.
One of the problems that we (UK) can and have experienced (and is the reason why a ground connection supplied to an RV cannot come from a ground that has been bonded to the neutral) is that, because the neutral is a current carrying conductor, there must be a (small) potential difference between its ends. If the ground is also bonded to the neutral conductor then this ground conductor will also be raised with respect to true earth. You now have a situation whereby the body shell of the RV can be raised to potential above that of the earth its standing on. The value this rise is a function of the current drawn by the system but occurs even on a healthy system. It is this effect that the regulation is designed to mitigate.
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