2 water services?

mopowr steve

Senior Member
Location
NW Ohio
Working on a project where 2 buildings are being combined as one occupancy. Side by side brick buildings.

The service with 2 main disconnect breakers is mounted at the exterior rear of building A and grounding of this service is attached to water line entering at the rear of this building A.

Now building B also has its own water service but enters completely opposite end of building which the owners at this point are not combining.

So the question is what is the code compliant way to bond this water service/copper line in building B with the water service in Building A.

A. Just bond the waterlines in both buildings together anywhere along there lengths.

B. Run bonding wire from within 5' of bldg A water entrance to building B waterline anywhere along its length.

C. Bond waterline to sub panel in building B anywhere along the length of waterline.

D. Bond waterline to subpanel in building B within 5' of water entry (as making it a 2nd grounding electrode), (? If the EGC feeding the subpanel can be used for the simultaneous purpose of GEC. Didn't 2014 allow this?)

E. Other I'm Open to suggestions/enlighten me.

Im a bit reserved thinking about if a potential fault occurred on the domestic water line (which has to go around a city block to serve both buildings) would a bonding wire be OK between buildings or could it become a fire hazard if it would need to carry fault current from one waterline to another by other services from other buildings. Have no idea if domestic waterlines underground are metallic around the city block.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
IMO you have 2 electrodes if the water lines are metallic so IMO you would have to run 2 separate runs from the service to within 5' of where both water lines enter the building.


250.68(C) Grounding Electrode Connections. Grounding electrode
conductors and bonding jumpers shall be permitted to
be connected at the following locations and used to extend
the connection to an electrode(s):
(1) Interior metal water piping located not more than 1.52 m
(5 ft) from the point of entrance to the building shall be
permitted to be used as a conductor to interconnect electrodes
that are part of the grounding electrode system.

250.50 Grounding Electrode System. All grounding electrodes
as described in 250.52(A)(1) through (A)(7) that are
present at each building or structure served shall be bonded
together to form the grounding electrode system. Where
none of these grounding electrodes exist, one or more of
the grounding electrodes specified in 250.52(A)(4) through
(A)(8) shall be installed and used.

I may be wrong about that but the least you would have to run a jumper between the water lines
 

infinity

Moderator
Staff member
Location
New Jersey
IMO you only need to use one of the water pipes. This is no different than using separate footings that contain 20' or more of 1/2" or larger rebar to make a CEE.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
IMO you only need to use one of the water pipes. This is no different than using separate footings that contain 20' or more of 1/2" or larger rebar to make a CEE.

Yes I get it but since each pipe run is a separate electrode then the nec states to use all available electrodes.

Does it matter? Maybe not but I am not sure the nec agrees with that thought. It is a good question because they are technically connected thru the community water (I assume community or city water).
 

kwired

Electron manager
Location
NE Nebraska
You should only need a continuous conductor to one electrode and can install bonding jumpers to the remaining electrodes.
 

mwm1752

Senior Member
Location
Aspen, Colo
Yes I get it but since each pipe run is a separate electrode then the nec states to use all available electrodes.

Does it matter? Maybe not but I am not sure the nec agrees with that thought. It is a good question because they are technically connected thru the community water (I assume community or city water).
You should only need a continuous conductor to one electrode and can install bonding jumpers to the remaining electrodes.
A couple of ways to skin this cat -- If this is indeed 2 separate structures then IMO -- use all available electrodes is the charging statement -- bonding jumpers are allowed as long as they are sized properly and one of the electrodes in the system is continuous -- UFER grounds are the only exception to exempt that only one of the mutiple avaliable UFER electodes need to be used. I believe I just pushed the "like" button :thumbsup:
 

mopowr steve

Senior Member
Location
NW Ohio
IMO you have 2 electrodes if the water lines are metallic so IMO you would have to run 2 separate runs from the service to within 5' of where both water lines enter the building.
[HR][/HR]


I think we have a winner!

This seems to make the most sense, although since I can attach bonding of other grounding electrodes to with the 5' of waterline entry this is the way I will go. Getting back out to the service would be to much challenge at this point.

Thanks
 

1964element

Senior Member
Location
Chicago
Homes in Chicago area all points grounded
Ufer
Driven rod
Water Street side
Jumped meter
Bonding and grounding
Is expensive

Sent from my E6782 using Tapatalk
 

infinity

Moderator
Staff member
Location
New Jersey
Does it matter? Maybe not but I am not sure the nec agrees with that thought. It is a good question because they are technically connected thru the community water (I assume community or city water).
My other thought. If they're connected together in the ground are they even two electrodes?
 

mopowr steve

Senior Member
Location
NW Ohio
My other thought. If they're connected together in the ground are they even two electrodes?
Without contacting the water company who really knows if the city water line under the street hasn't been changed to plastic?
So since I have copper entering (and assuming that they are at least 10' in length underground) both locations I don't know if they are truly metallicaly connected underground around the block.
 

infinity

Moderator
Staff member
Location
New Jersey
Without contacting the water company who really knows if the city water line under the street hasn't been changed to plastic?
So since I have copper entering (and assuming that they are at least 10' in length underground) both locations I don't know if they are truly metallicaly connected underground around the block.
Yes that's possible but you don't know if it's metal either. :)
 

macmikeman

Senior Member
Always there is so much fuss over how, and no mention of why. Why are we connecting a gec to a water pipe (per Nec of course but also- ) TO CREATE A PATH TO GROUND. If one of those water pipes is in direct contact with the soil for at least ten feet, and actually is a water line, then you should be good to go , unless your ahj is as confused about grounding as it would seem damn near almost every single other electrician in the USA other than your's truly. Sorry to be so megalomaniac about it.
 

mopowr steve

Senior Member
Location
NW Ohio
I think it's more about the fact, how does one treat the 2nd set of waterlines in the 2nd building when you only have one electric service.

One of the things that have crossed my mind--- since service is already connected to a waterline grounding electrode at building A ( and also a double set of ground rods ) do I just bond the second buildings copper lines to say the sub panel's EGC in that building as if they were a stand alone piping system.

Ahh, but this is what's interesting the second buildings water service ( and yes jumpered meter) in fact has a copper line entering from the street so as Dennis Alwon said it qualifies as another grounding electrode and should be treated as such. Which in turn means that, it too, should be connected to the service or original waterline grounding electrode (within the 5' rule )in building A.
 

kwired

Electron manager
Location
NE Nebraska
What about a building that has main water service entering it and one (or more) lines leaving it - all metallic lines?

I have ran into that a few times and only ran a GEC to withing 5 feet of main water service entry.

I have also had it where main water service entry had been replaced with non metallic piping but a metal pipe remained intact that left the building - and ran a GEC to within 5 feet of where that pipe leaves the building.
 

macmikeman

Senior Member
What about a building that has main water service entering it and one (or more) lines leaving it - all metallic lines?

I have ran into that a few times and only ran a GEC to withing 5 feet of main water service entry.

I have also had it where main water service entry had been replaced with non metallic piping but a metal pipe remained intact that left the building - and ran a GEC to within 5 feet of where that pipe leaves the building.
Thats what I'm talkin bout!:thumbsup:
 
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