Service Entrance and (2) 200 AMP disconnect setup

[Bama_Electrical]

New member here. I need some guidance on setting up a new service.

I have a 400 amp service from the utility to the meter base which will then feed (2) 200 amp disconnects. The utility requires the ground to be bonded in the meter. I have a #4 bare copper connected to 2 ground rods that will route into the meter base. The question that I have is with the neutral and the ground bonded in the meter, the neutral will then feed the neutral bar in the disconnects but should there also be a ground wire from the meter base the feeds a, separate from neutral, dedicated ground bar in the disconnect since the neutral and ground can only be bonded in one location. I have attached a diagram below that is similar but with only 1 disconnect.

Diagram

 

[Dennis Alwon]

The neutral at the meter and the first means of disconnects gets bonded to the can, The is no equipment grounding conductor that gets run from the meter to the panel. All the neutrals and grounds are together at the service. The service ends after the first disconnect and then you need the equipment grounding conductor.

 

[wwhitney]

[. . .] The utility requires the ground to be bonded in the meter. I have a #4 bare copper connected to 2 ground rods that will route into the meter base.

So that's your GEC and it serves the purpose of earthing the neutral conductor.

The question that I have is with the neutral and the ground bonded in the meter, the neutral will then feed the neutral bar in the disconnects but should there also be a ground wire from the meter base the feeds a, separate from neutral, dedicated ground bar in the disconnect since the neutral and ground can only be bonded in one location.

The EGC (ground) originates in the enclosure where you last use the neutral for bonding equipment (as is done in service equipment) and downstream start using the EGC to bond equipment with the neutral isolated from equipment cases.

That point where the EGC originates does not have to be the point where the GEC earths the neutral. In fact, the EGC has to originate in the service disconnect, while the GEC can earth the neutral anywhere on the service, e.g. upstream at the meter as your POCO requires.

So as Dennis says, you won't run an EGC out of the meter, you'll still just have the service conductors. And in the service disconnects, you'll still bond the cases to the service neutral.

Cheers, Wayne

 

[Bama_Electrical]

So GEC bonded to neutral in the Meter - 3 wires out (2 hots and a neutral) from the meter to both disconnects. In both disconnects, the ground bar will be bonded to the case and a bonding jumper between the neutral bar and the ground bar. Neutral and Ground run separately from there.

 

[Dennis Alwon]

So GEC bonded to neutral in the Meter - 3 wires out (2 hots and a neutral) from the meter to both disconnects. In both disconnects, the ground bar will be bonded to the case and a bonding jumper between the neutral bar and the ground bar. Neutral and Ground run separately from there.

That is correct

 

[Bama_Electrical]

One more question. Both of the breaker panels that are fed by the 2 disconnects will be located in a mechanical closet. The copper water line and the gas line will enter into the mechanical closet as well. Will I need a ground clamp and a ground wire on both the water and gas lines and will it need to go to 1 of the breaker panels or both? Really appreciate your help!

 

[LarryFine]

Welcome to the forum.

Will I need a ground clamp and a ground wire on both the water and gas lines and will it need to go to 1 of the breaker panels or both?

No.

The water-pipe clamp should be attached within 5' of the entrance into the house, and if there's an interior water meter, it should be jumpered around.

A gas-pipe ground, if required, should be attached only to rigid pipe, between the gas meter and that (the supply) end of any length of CSST gas tubing.

 

[Bama_Electrical]

In this case, the water line enters the building in the mechanical room, so grounding within 5ft is achievable. Thank you!

 

[Epalmateer]

The neutral at the meter and the first means of disconnects gets bonded to the can, The is no equipment grounding conductor that gets run from the meter to the panel. All the neutrals and grounds are together at the service. The service ends after the first disconnect and then you need the equipment grounding conductor.

With the new 230.85(3), I see the importance of saying "Service Disconnect" and not first disconnecting means.

 

[Dennis Alwon]

With the new 230.85(3), I see the importance of saying "Service Disconnect" and not first disconnecting means.

That is correct-- the first service disconnect is where the service ends

 

[electrofelon]

since the neutral and ground can only be bonded in one location.

Your confusion is probably because That is an incorrect statement.

 

[Epalmateer]

That is correct-- the first service disconnect is where the service en

Your confusion is probably because That is an incorrect statement.

Well, the neutral an egc can only be bonded in one location right? Before the service there is no egc.

 

[Epalmateer]

Your confusion is probably because That is an incorrect statement.

Unless you have more then one service disconnect, but those would considered 2 egc's

 

[Dennis Alwon]

Unless you have more then one service disconnect, but those would considered 2 egc's

If you have 2 service disconnects you still won't have an equipment grounding conductor until you leave the first service disconnect.

In the example of an emergency disconnect placed after the meter then that emergency disconnect is not considered service equipment if it is marked as such however there is still no equipment grounding conductor between the emo disconnect and the first service disconnect. All neutrals and equipment grounding conductor from feeders and branch circuits are bonded together until you leave the service panel.

 

[Epalmateer]

If you have 2 service disconnects you still won't have an equipment grounding conductor until you leave the first service disconnect.

In the example of an emergency disconnect placed after the meter then that emergency disconnect is not considered service equipment if it is marked as such however there is still no equipment grounding conductor between the emo disconnect and the first service disconnect. All neutrals and equipment grounding conductor from feeders and branch circuits are bonded together until you leave the service panel.

If you have 2 transfer switches with 2 service disconnects you will have 2 egc's

 

[Dennis Alwon]

If you have 2 transfer switches with 2 service disconnects you will have 2 egc's

It depends-- are the transfer switches suitable for service equipment- meaning does it have any overcurrent protective device. if so then that is the end of the service and anything from there would have an equipment grounding conductor.

 

[Epalmateer]

It depends-- are the transfer switches suitable for service equipment- meaning does it have any overcurrent protective device. if so then that is the end of the service and anything from there would have an equipment grounding conductor.

Yea like the case with OP. 400 amp service with 2 200 amp service disconnects

 

[Epalmateer]

It depends-- are the transfer switches suitable for service equipment- meaning does it have any overcurrent protective device. if so then that is the end of the service and anything from there would have an equipment grounding conductor.

And they make disconnects without OCPD that are suitable for use as service equipment

 

[Dennis Alwon]

And they make disconnects without OCPD that are suitable for use as service equipment

Yes, they do. So do you run an equipment grounding conductor from that Transfer Switch, that doesn't have overcurrent protective device, to the first panel.

 

[Epalmateer]

Yes, they do. So do you run an equipment grounding conductor from that Transfer Switch, that doesn't have overcurrent protective device, to the first panel.

No, because in that case it is not a service disconnect. By the way, I should have joined this forum years ago. It is so much better than Reddit.