Structure with 2 service disconnects and GEC installation

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sw_ross

Senior Member
Location
NoDak
Having a structure withe two or more service disconnects in separate enclosures, does the GEC tap that enters into each enclosure from the common GEC have to be an irreversible splice?

I'm referring to 250.64D and just trying to "get this right".

My current example scenario has two main breaker service panels, side by side. One is for single-phase loads, the other is for 3-phase loads (240v). When running my GEC from the metal underground water line electrode back to the panels what is the best (compliant) way to tap off that GEC for each service panel. GEC will be 4awg bare copper.

What I want to do is run the GEC back to the panels and take it into (terminate) the 3-phase panel, with a 4awg tap that terminates in the single phase panel. Do I have to use an irreversible crimp for that splice, or can I use something like a split bolt connection?

Thanks!
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Splices have to be irreversible, taps, such as a split bolt, do not.
Code states an "approved grounding connector" but most, i not all, split bolts are.
Note that your "common" electrode to your water pipe should be based on the service size for both panels.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Splices have to be irreversible, taps, such as a split bolt, do not.
Code states an "approved grounding connector" but most, i not all, split bolts are.
Note that your "common" electrode to your water pipe should be based on the service size for both panels.

Wouldn't that be based on the larger of the two if different?


ETA: What I meant and should have said is "based on service entrance conductors"
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
You can also terminate the GEC anywhere upstream of the service disconnecting means. Sometimes it's easier to run it into the meterbase/Ct cabinet and terminate it, than it is to run it separately into (2) or more service disconnects and have to use irreversible splices.

We still do it both ways, depends on my mood more often than not.
 

sw_ross

Senior Member
Location
NoDak
You can also terminate the GEC anywhere upstream of the service disconnecting means. Sometimes it's easier to run it into the meterbase/Ct cabinet and terminate it, than it is to run it separately into (2) or more service disconnects and have to use irreversible splices.

We still do it both ways, depends on my mood more often than not.

In NoDak we're required to have the GEC termination point be accessible (i.e.- not in the meter can).
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Wouldn't that be based on the larger of the two if different?


ETA: What I meant and should have said is "based on service entrance conductors"

Yes ! (luckily Rob has learned to interpret "old people talk").

In tying to word it I pictured a scenario in which I'm not sure of the answer.
To muddy the water a bit: 400 amp service with 3/0 cu to (2) 200 amp panels but the service conductor to the meter is an underground lateral supplied by POCO who elect to run a single 3/0. Now size your common GEC ! :D
 
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