2020 NEC : GEC and bonding screw with “emergency disconnect, service equipment”

This what the inspection agency here has been passing:
Typical 100A service:
EM disconnect with a #6 to a ground rod --- SE cable to basement panel ---
in basement service panel #6 bare to water pipe
The SE cable is being used to bond the two grounding electrode systems together.
Multiple GEC's can terminate in different locations. For example you can terminate the GEC for a ground rod electrode at the meter and the GEC for the water pipe electrode at the panel containing the service disconnect.
 
(3) A GEC at one location to one ground rod, a spliced bonding jumper at the other location to the other ground rod. I gather this is what you are saying does not comply with Article 250?



Cheers, Wayne
It maybe compliant but I still see ground loops and parallel neutral paths, so IMO I can see better ways of doing it.
 
After rereading your question I need to add that the GEC connection itself can be made directly to the Grounded Conductor but it can not be used as a jumper to other electrodes
Multiple GEC's can terminate in different locations. For example you can terminate the GEC for a ground rod electrode at the meter and the GEC for the water pipe electrode at the panel containing the service disconnect.
So your saying a grounded conductor can be a jumper to other electrodes?
 
It maybe compliant but I still see ground loops and parallel neutral paths, so IMO I can see better ways of doing it.
Absent an additional jumper directly from one ground to the other, any such loops and parallel paths go through the earth, so it that really a problem? Genuinely curious. A similar loop through the earth would exist any time a single service separately supplies two buildings.

Thanks,
Wayne
 
A similar loop through the earth would exist any time a single service separately supplies two buildings.

Thanks,
Wayne
Are these two buildings connected? Where would two buildings be served from one service with out one of them be supplied by a feeder?
 
Are these two buildings connected? Where would two buildings be served from one service with out one of them be supplied by a feeder?
I'm was thinking of say an underground service, an underground splice box, one set of service conductors exiting to one building, one set exiting to another building. [Although if those outgoing sets are interpreted to be SECs, then given 230.40, it would have to be an Exception 3 or Exception 5 application. I've never been clear if those outgoing sets are SECs or can just be underground service conductors.]

Although the same ground loop through the earth exists if the second building is supplied via a feeder.

Cheers, Wayne
 
We can keep adding scenarios and we are simply spinning our wheels. This thread has gone off track and I think if we are trying to keep discussing the GES and jumpers it might be better to start a new thread, what say you?
 
We can keep adding scenarios and we are simply spinning our wheels. This thread has gone off track and I think if we are trying to keep discussing the GES and jumpers it might be better to start a new thread, what say you?
Your the moderator I respect whatever you think is best.
Absent an additional jumper directly from one ground to the other, any such loops and parallel paths go through the earth, so it that really a problem? Genuinely curious.
What I have found is when one GEC is connected at the EM disconnect and another GEC at the service disconnect, if there is considerable distance between the two points and a metallic piping system such as CSST is installed that connects the two electrodes by way of multiple #6 jumpers form fittings, a measurable amount of neutral current will flow across the metal pipe.
 
What I have found is when one GEC is connected at the EM disconnect and another GEC at the service disconnect, if there is considerable distance between the two points and a metallic piping system such as CSST is installed that connects the two electrodes by way of multiple #6 jumpers form fittings, a measurable amount of neutral current will flow across the metal pipe.
Nothing in the NEC would prohibit that installation. Sounds like the bonding for the gas pipe is incorrect.
 
What I have found is when one GEC is connected at the EM disconnect and another GEC at the service disconnect, if there is considerable distance between the two points and a metallic piping system such as CSST is installed that connects the two electrodes by way of multiple #6 jumpers form fittings, a measurable amount of neutral current will flow across the metal pipe.
As you would expect. An argument for not doing that, either connect both electrodes to the grounded service conductor at the same point, or only bond the metallic piping system at one point to the GES. If the metallic piping system is bonded via equipment EGCs, that would mean only separately bonding the metallic piping system via the GEC/electrode closest to the MBJ.

Cheers, Wayne
 
Yes it would require that the incorrect bonding of the CSST be remedied. I was referring to bring a GEC to two separate pieces of equipment upstream of the service disconnect.
But you can end up with the situation mentioned even without any particular connection being wrong.

E.g. one electrode connected to the grounded service conductor at the meter, second electrode connected at the service disconnect. EGC of equipment supplied by the CSST bonds the CSST to the second electrode via the MBJ. Additional CSST bond required by the plumbing code connects the CSST to the first electrode.

You could fix the problem either by bonding the CSST to the second electrode instead of the first, or by ensuring the two electrode connections to the grounded service conductor are at the same location.

Cheers, Wayne
 
We could fix this whole stupid problem by calling a moratorium on separate EM disconnects

-Hal
Yeah thats what we have here, interesting discussion I am not up on this since we dont have it here, but a MGN system that the OP is discussing is in IEC terms a 'TN-C' system. You transition to a 4-wire TN-C-S at the Service disconnect, I wish the NEC used IEC terms for grounding and bonding.
If the distances are short between the EM and Service disconnect there is not an issue and the OP's install is legal in his state.
I know there was some discussion about it here in Oregon and the state decided to delete the entire section 230.85 from the Oregon Code.
They kinda did a 180, the state used to ammend the Oregon code to allow NEW 3-wire outdoor feeders long after 2005 but there had to be no parallel metallic paths, I believe in 2020 is when they were discussing parallel paths and got rid of the old exception and deleted all of 230.85 from the Oregon Code, so yeah we dont really have this issue in Oregon. Though one could still connect a ground rod in a meter can and have a water pipe ground in the service panel I have never seen that here as utilities dont allow it. But not a EM disconnect issue per se.
 
We could fix this whole stupid problem by calling a moratorium on separate EM disconnects
That happens in the 2026 code. The service disconnect for one- and two-family dwelling must be outside on the dwelling itself or remote from the dwelling in accordance with 110.29.
230.71(A)(1) One- and Two-Family Dwellings.
Service disconnects shall be installed in a readily accessible outdoor location in accordance with one of the following:
  1. On the dwelling unit
  2. Within sight of the dwelling unit in accordance with 110.29
Exception: The service disconnect shall not be required to be installed on or within sight of the dwelling unit when an emergency disconnect is installed in accordance with 225.41.
230.70(B) Service Disconnect Marking.
Service disconnects shall be marked in accordance with 230.70(B)(1) and 230.70(B)(2).
(1) Marking.
Service disconnects shall be marked “SERVICE DISCONNECT.” The marking shall be on or adjacent to the service disconnect and comply with 110.21(B).
(2) One- and Two-Family Dwellings.
Enclosures of disconnects for one- and two-family dwellings shall be marked as follows: “EMERGENCY DISCONNECT.”

Markings shall comply with 110.21(B) and both of the following:
  1. The markings shall be located on the outside front of the disconnect enclosure with a red background and white text.
  2. The letters shall be at least 13mm (1⁄2 in.) high.
 
That happens in the 2026 code. The service disconnect for one- and two-family dwelling must be outside on the dwelling itself
Is that going to force the manufacturers of meter cans to put a switch in the can with a handle on the side so that nothing is changed? 3-wire in, 3-wire out to a main panel with a main CB and bonding there? Or is this looking for a main CB outside of the dwelling which changes nothing as far as what is discussed.

-Hal
 
Or is this looking for a main CB outside of the dwelling which changes nothing as far as what is discussed.
Everything changes.

The service disconnect must be outside, It can be a meter main, or a fused disconnect, or an enclosed breaker. It maybe be confusing because the service disconnect must be marked "emergency disconnect. You just have to forget everything you knew about the emergency disconnect under the 2020 and 2023 codes.

A four wire feeder is required to be run to the panel inside the dwelling.

All GECs will connect within or on the line side of the service disconnect.
 
You just have to forget everything you knew about the emergency disconnect under the 2020 and 2023 codes.
Or were trying to figure out.

The service disconnect must be outside, It can be a meter main, or a fused disconnect, or an enclosed breaker.

A four wire feeder is required to be run to the panel inside the dwelling.

All GECs will connect within or on the line side of the service disconnect.

I don't like the idea of a main breaker outside in the elements, but at least we now have ONE way to do it that we all should know how to do. (y)

-Hal
 
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