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If you had a 2000a and a 3000a service located in the same room, and two separate domestic water mains, would both need to be hit from each service to prevent causing two separate ground grids?
Everything needs to be at the same potential no?
I have done a few services in the 2000a range but never a building with two water mains.
 

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IBEW L.U. 1852
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If you had a 2000a and a 3000a service located in the same room, and two separate domestic water mains, would both need to be hit from each service to prevent causing two separate ground grids?
Everything needs to be at the same potential no?
I have done a few services in the 2000a range but never a building with two water mains.
You've answered your own question. When you have a building with a domestic water main and a sprinkler water main........do you not bond both of the mains?

I can't think of a situation where I would have a 2000 A and a 3000A service in the same room though. Would'nt you just bring in one larger service to the building and split it into seperate distribution for the different areas???

Although by the time you get into bigger services like that (6000 amp and such) you are getting into some very big switchgear and usually some high voltages and the methods of grounding start getting a lot different than just tagging a few ground rods or a water main.
 

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If you had a 2000a and a 3000a service located in the same room, and two separate domestic water mains, would both need to be hit from each service to prevent causing two separate ground grids?
Everything needs to be at the same potential no?
I have done a few services in the 2000a range but never a building with two water mains.
Both services are required to be connected to the same grounding electrode systems.


250.58 Common Grounding Electrode. Where an ac system is connected to a grounding electrode in or at a building or structure, the same electrode shall be used to ground conductor enclosures and equipment in or on that building or structure. Where separate services, feeders, or branch circuits supply a building and are required to be connected to a grounding electrode(s), the same grounding elec-trode(s) shall be used. Two or more grounding electrodes that are bonded to-gether shall be considered as a single grounding electrode system in this sense.
 

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IBEW L.U. 1852
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Both services are required to be connected to the same grounding electrode systems.
Thanks BBQ...........your code article explains what I was trying to get at. I just got up and my head is still a bit sleep addled:laughing:

Im trying to get this first coffee into me though
 

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Discussion Starter #5
You've answered your own question. When you have a building with a domestic water main and a sprinkler water main........do you not bond both of the mains?

I can't think of a situation where I would have a 2000 A and a 3000A service in the same room though. Would'nt you just bring in one larger service to the building and split it into seperate distribution for the different areas???
2 domestic water mains, and 1 sprinkler main.
This is one of the largest mills in the country sq. Footage wise. Its going to be mixed occupancy when done. The 2 separate services are supplied bye individual xformers.

My gut tells me to hit everything ( both waters, gas, and sprinkler) from each piece of equipment.
 

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there is an article on one service per building. only under special permission are you allowed more than one.
The need of 5000 amps would be a reason without needing special permission.

230.2 Number of Services. A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D). For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.

(C) Capacity Requirements. Additional services shall be permitted under any of the following:

(1) Where the capacity requirements are in excess of 2000 amperes at a supply voltage of 600 volts or less
 

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good call. that one was above my pay scale:laughing:. never dealt with anything that big without having high voltage coming in .
It does seem odd to dump 5000 amps in one room.

We seem to max out at about 3000 before we are doing another service in a different location. We did a large distribution refrigerated warehouse that had seven 3000 amp feeders entering the building at different locations. Medium voltage was used outside the building to distribute it.
 

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The way I would approach it would be to ground each service as you normally would. Hit building steel, hit the water main associated with each service, ground rods (if necessary), and hit the sprinkler main, then bond the services together.

It could be argued you wouldn't even need to bond the services as they would already be bonded via the sprinkler and building steel. I would talk to the inspector to see what he would require.
 

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I'd talk to the sprinkler guy about bonding his riser. We don't do it. Also I'd run a MBJ from building steel to water, this allows you to only have to hit building steel for your GEC when you're in there setting transformers someday.
 

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You are correct, the building steel would do it.


I saved a 300' run of pipe with 3/0 copper to the water main by using the building steel as the conductor.
 

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BBQ said:
You are correct, the building steel would do it. I saved a 300' run of pipe with 3/0 copper to the water main by using the building steel as the conductor.
Yeah our buildings total well over a million sq ft. And the water service only comes in one corner. I couldn't imagine having to run a GEC back to the water room every time I set a transformer
 

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Deep Cover said:
Why not? Is there a local amendment?
I'm not sure I've just never done it. The water and the sprinkler come into the building 5' from each other and come off the same main at the road. Maybe it is bonded I don't know. Quit yelling at me!
 

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BBQ said:
250.104 requires bonding it.
I don't see anything about sprinklers in there. Are you implying when they say metal water piping system they are talking about the sprinkler system AND the water system?
 

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I don't think you can see it any other way.

(1) MetalWater Piping System(s). The grounded conductor
of each separately derived system shall be bonded to the
nearest available point of the metal water piping system(s)
in the area served by each separately derived system. This
connection shall be made at the same point on the separately
derived system where the grounding electrode conductor
is connected. Each bonding jumper shall be sized in
accordance with Table 250.66 based on the largest ungrounded
conductor of the separately derived system.

Exception No. 1: A separate bonding jumper to the metal
water piping system shall not be required where the metal
water piping system is used as the grounding electrode for
the separately derived system and the water piping system
is in the area served.

Exception No. 2: A separate water piping bonding jumper
shall not be required where the metal frame of a building or
structure is used as the grounding electrode for a separately
derived system and is bonded to the metal water
piping in the area served by the separately derived system.
 

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I don't see anything about sprinklers in there. Are you implying when they say metal water piping system they are talking about the sprinkler system AND the water system?
We can go that way or we can go this way .....


250.104(B) Other Metal Piping. Where installed in or attached to a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
But either way I don't see escaping bonding the sprinkler system.

We generally do it at the main water entrance because it usually comes in next to the domestic water.
 
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