2 services 1 building GEC

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yired29

Senior Member
So, There is no room available for service equipment accessible to both occupants ?

Maybe 230.2 (C) 3

The AHJ gave special permission for the two services. We are just debating GE and GEC rules I site 250.58

Two or more grounding electrodes that are effectively bonded together shall be considered as a single grounding electrode system in this sense.

Once all are bonded together than building steel is an electrode anywhere in the building. That is the way I interpret this rule. It has been told to me we would be using building steel as a GEC when used like this to comply with 250.50 but I don't understand how building steel can be both a GE and a GEC.

I know it is ultimately up to the AHJ but trying to get as much input as possible. Maybe a better way to state my case. Around here I get mixed response from local inspectors.
 
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Jim W in Tampa

Senior Member
Location
Tampa Florida
Maybe 230.2 (C) 3

The AHJ gave special permission for the two services. We are just debating GE and GEC rules I site 250.58

Two or more grounding electrodes that are effectively bonded together shall be considered as a single grounding electrode system in this sense.

Once all are bonded together than building steel is an electrode anywhere in the building. That is the way I interpret this rule. It has been told to me we would be using building steel as a GEC when used like this to comply with 250.50 but I don't understand how building steel can be both a GE and a GEC.

I know it is ultimately up to the AHJ but trying to get as much input as possible. Maybe a better way to state my case. Around here I get mixed response from local inspectors.

Simply put this does not seem to follow nec. You have an inspector that for what ever reason is bypassing nec . So what ever else he wants to bypass must be ok too. Sounds like it just too costly to do it to code.Just my opinion on what has been presented so far. Is there a reason other than cost ?
 

yired29

Senior Member
Simply put this does not seem to follow nec. You have an inspector that for what ever reason is bypassing nec . So what ever else he wants to bypass must be ok too. Sounds like it just too costly to do it to code.Just my opinion on what has been presented so far. Is there a reason other than cost ?

Is it your position a GEC should be run from service 2 400' to water main within 5' from entrance of building were all other GE are attached.

This question was asked to see if in this situation what the consensus would be on this forum.

Building steel as electrode at 2nd service and that it.
or
run back to water main as described.
 

RooKie12

Member
Your new service requires it's own separate Electrodes (2), if your new electrical service is in the back of the building and the water entrance is at the front you can use the steel as a conductor as long as when you tap onto the steel at each end it's by irreversible means (cad-weld) and correctly sized then just drive your ground rod for your second electrode.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Your new service requires it's own separate Electrodes (2), if your new electrical service is in the back of the building and the water entrance is at the front you can use the steel as a conductor as long as when you tap onto the steel at each end it's by irreversible means (cad-weld) and correctly sized then just drive your ground rod for your second electrode.

WoW! I need a copy of your Code.
If I have either an effectively grounded buildng steel or a concrete encased electrode, can you show me where I must have any additional electrodes ? (if no others are present)
also can you show me where my connections must be cadweld ?
 

yired29

Senior Member
Your new service requires it's own separate Electrodes (2), if your new electrical service is in the back of the building and the water entrance is at the front you can use the steel as a conductor as long as when you tap onto the steel at each end it's by irreversible means (cad-weld) and correctly sized then just drive your ground rod for your second electrode.

Take a look at 250.70
 

RooKie12

Member
WoW! I need a copy of your Code.
If I have either an effectively grounded buildng steel or a concrete encased electrode, can you show me where I must have any additional electrodes ? (if no others are present)
also can you show me where my connections must be cadweld ?

Not saying that you have to have those as your electrodes but was saying if you use your steel as a GEC the connections to the steel has to be by irreversable means. As long as you have your 2 electrodes your good.


250.64
(C) Continuous. Grounding electrode conductor(s) shall
be installed in one continuous length without a splice or
joint except as permitted in (1) and (2):
(1) Splicing shall be permitted only by irreversible
compression-type connectors listed as grounding and
bonding equipment or by the exothermic welding process
.
 

yired29

Senior Member
Not saying that you have to have those as your electrodes but was saying if you use your steel as a GEC the connections to the steel has to be by irreversable means. As long as you have your 2 electrodes your good.


250.64
(C) Continuous. Grounding electrode conductor(s) shall
be installed in one continuous length without a splice or
joint except as permitted in (1) and (2):
(1) Splicing shall be permitted only by irreversible
compression-type connectors listed as grounding and
bonding equipment or by the exothermic welding process
.

Did you read 250.70?
250.64 refers to conductor being continuous if not needs to be irreversible.
We ars talking about a grounding electrode conductor to grounding electrode connection (250.70).
How do you make your connection to a ground rod? (Acorn)
 

RooKie12

Member
Yes but when you go from the connection to your electrode (on the water pipe clamp) to the equipment or common point the conductor in between the 2 points have to be uncut or spliced by irreversible means which means the conductor connecting to the steel at each end has to be irreversible means

As for where i get the need for 2 electrodes unless the electrical contractor provides proof of 25ohms or less on his one electrode you'll need the additional electrode. (how many people have the equipment to show the resistance to ground?)



250.56 Resistance of Rod, Pipe, and Plate Electrodes. A
single electrode consisting of a rod, pipe, or plate that does
not have a resistance to ground of 25 ohms or less shall be
augmented by one additional electrode of any of the types
specified by 250.52(A)(4) through (A)(8). Where multiple
rod, pipe, or plate electrodes are installed to meet the requirements
of this section, they shall not be less than 1.8 m
(6 ft) apart.
 

RooKie12

Member
I think your talking about just going from the steel to the equipment. using the steel as your electrode which your connections don't have to be irreversible. If you use your steel as a conductor your connection to the steel do have to be. Think we're talking about two different things
 

yired29

Senior Member
Yes but when you go from the connection to your electrode (on the water pipe clamp) to the equipment or common point the conductor in between the 2 points have to be uncut or spliced by irreversible means which means the conductor connecting to the steel at each end has to be irreversible means

This means you are calling building steel a grounding electrode conductor not a grounding electrode.
 

RooKie12

Member
This means you are calling building steel a grounding electrode conductor not a grounding electrode.

Let's say your wanting your 2 electrodes to be a rod type and a water ground. The building is 200 ft long and the water entrance is in the front of the building and your service is in the rear of the building. You can go from your equipment up to the steel right above your equip and make a irreversable connection to the steel and then at the front of the building drop down from the steel above your water main and your steel in between becomes your conductor yes. Which saves you from running the wire all that way. Never heard of that method?
 

yired29

Senior Member
Let's say your wanting your 2 electrodes to be a rod type and a water ground. The building is 200 ft long and the water entrance is in the front of the building and your service is in the rear of the building. You can go from your equipment up to the steel right above your equip and make a irreversable connection to the steel and then at the front of the building drop down from the steel above your water main and your steel in between becomes your conductor yes. Which saves you from running the wire all that way. Never heard of that method?

Once you make a connection from water to steel, the steel is now an electrode. NEC 2005

How can it be both a GEC and a GE

What if your steel is assembled using nuts and bolts they are reversible.

Aside from the cadweld portion of this discussion, the second service would only need to go to building steel in the area of the second service in your opinion?
 

RooKie12

Member
Yes if the first service went from the water clamp the the steel you could just drop down from the steel to your new equip and you'd have your water ground but both connections to the steel would be required to be irreversible here.
 
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