Silly GEC termination question

[greeny]

Why do I see the ground rod wire being terminated in the meter box and the water service wire being terminated in the panel? Obviously it's for ease of installation/cost of wire, but I thought the GECs needed to terminate at the same location. Is the neutral between the meter and panel considered one long bus? What code section permits this?

 

[augie47]

250.24(A)(1) is your Code section and it permits the GEC connections to be located at any accessible point up to and including the service disconnect so, in a way, you could look at the grounded conductor as one long buss.

 

[George Stolz]

Must be a NH thing. Around here they both land in the service disconnect (pole services notwithstanding).

 

[greeny]

Thanks for the help guys! How is the meter box bonded to ground if the main bonding jumper is installed at the panel? This is assuming the use of SEU cable.

 

[George Stolz]

Everything ahead of the service disconnect is bonded to the neutral.

 

[Dennis Alwon]

I usually land the gec to the rod in the meter and the gec to the water pipe in the panel. Just easier if one is outside and the other is inside.

 

[infinity]

I usually land the gec to the rod in the meter and the gec to the water pipe in the panel. Just easier if one is outside and the other is inside.

That's how I would do it but the POCO's around here do not allow the connection to be installed in their meter enclosure so we run both GEC"s back to the panel or service disconnect.

 

[greeny]

Alright, so the conductance of the parallel current path between the two grounding electrodes is small enough to be considered not dangerous/negligible?

 

[Dennis Alwon]

Alright, so the conductance of the parallel current path between the two grounding electrodes is small enough to be considered not dangerous/negligible?

You would not get much current to a rod under normal circumstances. Remember the GE is really for lightning or power surges not as an alternate means of a path to ground.

Every commercial install that has conduit between the meter and the main panel has a parallel path on the neutral. I never understood why they allowed that.

 

[jclint07]

Around here, POCO will not allow our electricians to land the GEC in the main disconnect AND install a ground rod at their meter base. They require concrete encased electrode OR ground rod in their metering equipment, which according to 250.24 (A1) is acceptable by code. BTW, when your grounding electrode conductor is installed, whether it be to the ground rod or concrete electrode, isn't running another bare copper to the water main coming in just for BONDING purposes only (250.104), not an actual suppemental electrode?

 

[jumper]

Around here, POCO will not allow our electricians to land the GEC in the main disconnect AND install a ground rod at their meter base. They require concrete encased electrode OR ground rod in their metering equipment, which according to 250.24 (A1) is acceptable by code. BTW, when your grounding electrode conductor is installed, whether it be to the ground rod or concrete electrode, isn't running another bare copper to the water main coming in just for BONDING purposes only (250.104), not an actual suppemental electrode?

If the water line qualifies as an electrode than you must use it, it is not supplemental. While you would use T250.66 for sizing the conductor in either case, the point of connection may be different. A bonding jumper to the water line may be anywhere on the system, while a GEC connection must occur within 5' of where it enters the building.

 

[jclint07]

Question #1, if the metal water main meets the requirements of being AN electrode and is used as such, then wouldn't that satisfy the requirement to bond the metal water piping system as well (250.104)?

Question #2, if the metal water piping is used as an ELECTRODE, in addition to a concrete encased electrode, landing the metal water piping electrode conductor in a sub panel would be a clear violation, correct? BUT if metal water piping system does not qualify as an electrode and just has a bonding jumper attached to it, then landing that metal water piping bonding jumper in a sub panel would STILL be a violation, correct?

 

[Steviechia2]

Question #1, if the metal water main meets the requirements of being AN electrode and is used as such, then wouldn't that satisfy the requirement to bond the metal water piping system as well (250.104)?

If the water main is connected to your service then you could use it to bond another water system

Question #2, if the metal water piping is used as an ELECTRODE, in addition to a concrete encased electrode, landing the metal water piping electrode conductor in a sub panel would be a clear violation, correct?

YES>

BUT if metal water piping system does not qualify as an electrode and just has a bonding jumper attached to it, then landing that metal water piping bonding jumper in a sub panel would STILL be a violation, correct?

You can bond the metal water pipe off of your sub panel.

 

[jumper]

You can bond the metal water pipe off of your sub panel.

You sure about that?

250.104(a)(1) General. Metal water piping system(s) installed in or
attached to a building or structure shall be bonded to the
service equipment enclosure, the grounded conductor at the
service, the grounding electrode conductor where of sufficient
size, or to the one or more grounding electrodes used.
The bonding jumper(s) shall be sized in accordance with Table
250.66 except as permitted in 250.104(A)(2) and (A)(3).

 

[roger]

IMO, all GE's should be bonded to one location, the more places the GES is connected to the service neutral such as in the "Meter" and then the "Main", the more chances there are for RFI, EMF, objectionable current paths, etc... IOW's, there should be a single connection to the GES from one location.


BTW, I know multiple locations are allowed but it is not the best design IMO


Roger

 

[jumper]

IMO, all GE's should be bonded to one location, the more places the GES is connected to the service neutral such as in the "Meter" and then the "Main", the more chances there are for RFI, EMF, objectionable current paths, etc... IOW's, there should be a single connection to the GES from one location.


BTW, I know multiple locations are allowed but it is not the best design IMO


Roger

Works for me, besides it helps get rid of them pesky inspectors quicker.

 

[Greg1707]

ground bar clamp

ground bar clamp

I believe I have seen on this board a bar type ground clamp that can be attached to the meter enclosure. It has a screw on one end to tighten and secure to can. I assume the GEC for the ground rods can be attached to this clamp. Does anyone have a photo or opinion on this method? It allows the GEC for rods to be installed without running inside the house and also does not require access to the inside of the POCO equipment.