Robert, if the green conductor by the neutral is going back to the meter, what are they doing? running parallel grounded conductors? green color? GEC on grounding bus? something smells funky. Rookie wired this thing or someone messed with it?
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See below - three more photos for clarity.
The GEC not being able to terminate on the ground bus bar just seems counter-intuitive to me. What is the logic I wonder?
And that is because 250.24(A)(4) mentions a wire or busbar but NOT a screw?
Michael it does seem like the 4 wires HHNG go straight outside to the meter base directly on the other side of the wall. 1 foot run.
For a 1Ø, 120/240 volt system there should only be three conductors from the meter to the panel. As you’ve correctly stated if there are four then two are possibly in parallel which is not permitted for two different sized conductors.
Yes you’re correct, use a screw as the MBJ and the GEC’s must land on the neutral bus or somewhere upstream of that point. Change the screw to a properly sized wire type MBJ and you can land the GEC’s on the EGC bus.
Rob
Agreed. Now do you have a problem with both a solid copper MBJ and having the bonding screw remaining?
I don’t. Just asking…
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Good question, I thought about that while I was composing my last post. I’m leaning towards thinking that there should only be one MBJ due to the use of singular wording in the NEC for the MBJ. I don’t think that electrically it would make much of a difference.
Only reason that I ask is often someone might not understand the request to remedy so leaving the screw assures that bonding remains.
Example, they jump the 2 N bars.
Ask the boys and let us know.
Looking at all of the pictures and reading the OP’s additional comment it appears the panel is grounded by the solid copper wire on the grounding bar the green wire is a bonding jumper to the gas meter and the panel is bonded by the green screw as it should be in a service panel. The green wire does not go back to the meter, If so I vote it is confusing but OK.
How did you determine this? you may have misread post #18 The green conductor disappears into the conduit going to the meter.
As far as i know
*Green insulated wire next to neutral wire - goes to meter base
*Bare copper wire on ground bus - goes to ground rod
*Bare copper wire on ground bus - goes to gas meter
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This is set up to be a 4 wire. Don’t know why…
An electrician needs to come out. Following any recommendations here is not recommended.
Bottom line is that there are issues.
Since the service raceway is PVC there is no reason for the “4th wire”. It is most likely in parallel with the neutral it would be a direct violation of 250.6(A). Also in this case a GEC cannot terminate on the EGC bus.
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Hypothetical situation - I dont think this is true - buuuuuut
What if that green wire went to another ground rod? or another acorn on the same ground rod?
Are two GECs allowed? parallel GECs?
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That is a good question. I’ve seen many installations that have multiple ground rods and other ground connections. As for the “Allowed” part of your question, only the local inspection authority can answer that. I would allow it. Someone else might not.
As I see it, the important thing is to be able to look at a system and understand how electricity will flow under different circumstances. One thing you never see in these discussions on message boards, for example, is any discussion of where and how the electricity will flow in a non-sinusoidal fault. That’s one of the first things I think about when evaluating grounding and bonding. I don’t give a crap about codes if I know where the electricity is going to go.
It is like the old joke about the guy who was killed in a car crash and his tombstone read “He Had The Right of Way”.
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If one was to a ground rod and one was to a metal water line (10’ outside the structure) those would be paralleled conductors.
I don’t know IF they are prohibited - but I don’t think so
@dmarchese2
More than one GEC is permitted. Anything that qualifies, and is present, as the Grounding Electrode HAS to be grounded. Building steel, Ufer, Water pipe, ground rod ETC… and in some cases. (pipe, plate or rod) a supplemental must be installed. Unless they’re all next to each other, the contractor is gonna run a separate wire for each one. You cannot parallel the GEC though, aka two wires to the same electrode.
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That is helpful, Ryan…simple and informative. Thanks! 
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I did know. I just forgot.
Kind of true.one one GEC exists in every service. Everything else is a bonding jumper.
250.62
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That would be true if there were one GEC run to an electrode and a jumper(s) between that and the other electrode(s). If each electrode has a conductor run back to the neutral bus of the panel then each of those conductors would be a GEC.
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