Grounding conductor connection inside main service panel

[Andres Arias]

Hello everybody.
As far as I understand, the grounding conductor should be connected inside the panel before leaves the panel, right in the bushing installed in the knockout, as presented in the picture attached "Grounding cond connected", however I have seen that some panels have their grounding conductors not connected in the bushing of the knockout (see attached "Grounding cond no connected").

Question: Which of the two cases is valid for the grounding conductor inside the main service panel, in such a way that the electrical inspection does not fail ?

Thank you

 

[LarryFine]

In my opinion, the pics are backwards. The single greens, if in metallic conduit/raceway, should have been bonded, while the EGC need not have been.

(Note that the bonding is actually connecting the raceway to the conductor (at both ends) it contains.

 

[roger]

IMO a bond bushing is not necessary for either one.

 

[LarryFine]

IMO a bond bushing is not necessary for either one.

Metallic GEC conduits don't need to be bonded to the GEC?

 

[infinity]

Your terminology is what confusing you. The one green conductor alone in the photo appears to be a GEC the other an EGC. The EGC does not require a bonding bushing at that voltage. The GEC is required to bonded to a ferrous metal raceway when installed in one. That appears to just be an NM cable connector so none is not require there either.

 

[don_resqcapt19]

Metallic GEC conduits don't need to be bonded to the GEC?

Where connected to the metal enclosure that the GEC is terminated in, I see no reason for additional bonding.

 

[LarryFine]

The one green conductor alone in the photo appears to be a GEC the other an EGC.

I see what appear to be three lone greens, but the far left one could be the feeder EGC.

The one with the micrometer on it looks like it's coming through an EMT connector.

The other one looks like it's in an MC connector, and a bit of flex seems to be visible.

The EGC does not require a bonding bushing at that voltage.

I know and agree.

The GEC is required to bonded to a ferrous metal raceway when installed in one. That appears to just be an NM cable connector so none is not require there either.

You may well be correct about that. It does appear to be clamped against the back of the connector.

 

[LarryFine]

Where connected to the metal enclosure that the GEC is terminated in, I see no reason for additional bonding.

I'm trying to remember if I used them when leaving metallic enclosures. But, I don't.

 

[Andres Arias]

Your terminology is what confusing you. The one green conductor alone in the photo appears to be a GEC the other an EGC. The EGC does not require a bonding bushing at that voltage. The GEC is required to bonded to a ferrous metal raceway when installed in one. That appears to just be an NM cable connector so none is not require there either.

Actually I am refering in the photos to the Electrode Grounding Conductor, which leaves the main panel and goes to the electrode rod or to the water shutoff (or to a collector bar when several panels are installed together, and from the collector bar to the electrode rod). Thank you for the clarification in regards with how to treat the Grounding Electrical Conductor, which is not necessary to bond in the knockout, when the EGC does.

 

[infinity]

Is this actually a service? Do you have a photo of the entire panel?

 

[suemarkp]

EGC - Equipment Grounding conductor
GEC - Ground Electrode Conductor

The two are different, serve different purposes, and have different rules for sizing and use. Don't want to confuse them.

 

[Andres Arias]

EGC - Equipment Grounding conductor
GEC - Ground Electrode Conductor

The two are different, serve different purposes, and have different rules for sizing and use. Don't want to confuse them.

Yes, I meant EGC - Equipment Grounding conductor and GEC - Ground Electrode Conductor

 

[hornetd]

IMO a bond bushing is not necessary for either one.

I'm not arguing! I really am asking. Does the presence of the reducing washes explain the use of the bonding bushing? Even if it is not required wouldn't it be considered good practice?

Tom Horne

 

[roger]

I'm not arguing! I really am asking. Does the presence of the reducing washes explain the use of the bonding bushing? Even if it is not required wouldn't it be considered good practice?

Tom Horne

And respectfully no, it's just wasted resources and money

 

[Andres Arias]

Dear colleagues. This is a summary so far in regards with the grounding inside the main service panel (kindly let me know if there is something wrong/missing):

For Equipment Grounding Conductor EGC. The EGC should run inside the pipe between the electric meter and the panel. EGC should also be running inside the pipes of the branch circuits. In all the cases (for branch circuits and pipe between meter and panel), the EGC should be connected to the panel case using knockout bonding.

For Grounding Electrode Conductor GEC. The GEC should be connected to the panel case using knockout bonding, as long as the GEC runs through a pipe from the panel to the electrode, or is cable armor. Otherwise, it is not needed to be bonded in the panel case, right at the knockout.

See attached several photos in which, in my opinion, existing grounding electrode conductor (bottom of panel) should be properly connected to the panel case using knockout bonding; and Equipment Grounding Conductor is missing for several branch circuits, particularly those at the top of the panel. Notice that the branch circuits leaving the panel at the left side do have their corresponding EGC.

Thanks

 

[david]

Dear colleagues. This is a summary so far in regards with the grounding inside the main service panel (kindly let me know if there is something wrong/missing):

Supply side bonding jumper
Bonding jumper
main bonding jumper
grounding electrode conductor
equipment ground
Equipment ground & wire type equipment ground

For Equipment Grounding Conductor EGC. The EGC should run inside the pipe between the electric meter and the panel.

equipment grounds originate after the main bonding jumper.

i know you are talking about meters that are normally on the supply side of the service disconnect.

EGC should also be running inside the pipes of the branch circuits. In all the cases (for branch circuits

if your installing a wire type equipment ground

and pipe between meter and panel),

the EGC should be connected to the panel case using knockout bonding.

i think you're talking about a bonding jumper

For Grounding Electrode Conductor GEC. The GEC should be connected to the panel case using knockout bonding,

the GEC usually connects to a buss that the neutral is connected to using that buss as a bonding jumper to make a direct conection to the neutral/ grounded conductor.

It can connect two another buss as long as there is a correct size bonding jumper connecting to the neutral buss

as long as the GEC runs through a pipe from the panel to the electrode, or is cable armor. Otherwise, it is not needed to be bonded in the panel case, right at the knockout.

See attached several photos in which, in my opinion, existing grounding electrode conductor (bottom of panel) should be properly connected to the panel case using knockout bonding;

and Equipment Grounding Conductor is missing for several branch circuits, particularly those at the top of the panel. Notice that the branch circuits leaving the panel at the left side do have their corresponding EGC.

those look yo me to be AC cable with a steel jacket. Notice the bonding jumper wrapped around the steel cable
i say steel cable because of the set screw AC box connector

The other cables look to be MC cables those haveing the green equipment ground with in the cable.

Thanks

 

[david]

Dear colleagues. This is a summary so far in regards with the grounding inside the main service panel (kindly let me know if there is something wrong/missing):

Some of this has already been commented on in this thread I hope you found their comments helpful

 

[Andres Arias]

Supply side bonding jumper
Bonding jumper
main bonding jumper
grounding electrode conductor
equipment ground
Equipment ground & wire type equipment ground

equipment grounds originate after the main bonding jumper.

i know you are talking about meters that are normally on the supply side of the service disconnect.

if your installing a wire type equipment ground



i think you're talking about a bonding jumper

the GEC usually connects to a buss that the neutral is connected to using that buss as a bonding jumper to make a direct conection to the neutral/ grounded conductor.

It can connect two another buss as long as there is a correct size bonding jumper connecting to the neutral buss





those look yo me to be AC cable with a steel jacket. Notice the bonding jumper wrapped around the steel cable
i say steel cable because of the set screw AC box connector

The other cables look to be MC cables those haveing the green equipment ground with in the cable.

Many thanks Sir. It's much clearer for me.

 

[Andres Arias]

Some of this has already been commented on in this thread I hope you found their comments helpful

Certainly!!. Thanks for the answers.

 

[wwhitney]

For Equipment Grounding Conductor EGC. The EGC should run inside the pipe between the electric meter and the panel.

No, on the utility side of the service disconnect, there is no "ground" or EGC. The grounded conductor (neutral) is used for bonding all metal enclosures.

EGC should also be running inside the pipes of the branch circuits.

Or for some wiring methods the pipes can be the EGC, e.g. EMT, RMC, etc., no wire required.

In all the cases (for branch circuits and pipe between meter and panel), the EGC should be connected to the panel case using knockout bonding.

No, there are special bonding requirements if you have a metal raceway for service conductors or over 250V to ground, see 250.92 and 250.97. A wire type EGC in the conduit, if present, could double as the bonding jumper if such a situation requires the use of a bonding bushing/locknut/wedge. Or you could use a separate bonding jumper, and just run the EGC to the ground bus.

For Grounding Electrode Conductor GEC. The GEC should be connected to the panel case using knockout bonding, as long as the GEC runs through a pipe from the panel to the electrode, or is cable armor.

No, since the GEC is going to be landed on the grounded conductor busbar, which is going to be bonded to the case already, there is no need for duplicate bonding at the entry into the case. If it exits the enclosure in a metallic raceway or armor, then at the other end of that metallic raceway or armor, the GEC will need to be bonded to it as it exits.

I did not look at your attached photos.

Cheers, Wayne