320 Amp Service, Two Panels in Separate Structures, Disconnect Question

[westtx28]

Couple of years ago customer had a 320 Amp service installed on side of shop building with the intention of servicing the shop with one 200 Amp panel and the option to add another 200 Amp panel to a separate future home structure. Forward to now home construction is starting and I’m looking at this and have some questions about the setup. Currently the shop has a 200 Amp with main breaker set on the back of the meter base inside shop. Meter base has second set of service entrance conductors going to a 200 Amp breaker set beside meter base. See picture customer provided from initial install.

Because there is an OCPD, I assume the conductors running to the 2nd panel to be located in the house are no longer service conductors but are feeders requiring a 4-wire feed. If this is the case where does the EGC run? To the bonded panel 1 EGC? Does this leave me with a disconnect grouping situation?

I understand what the original intent was but would it be better to propose to remove the OCPD and run a 3-wire service entrance feed to the 2nd panel? House is 200 feet away by the way.

 

[Dennis Alwon]

The install is not compliant... bith panels are main panels and their conductors are service conductors. The disconnects need to be grouped

 

[iwire]

I agree with Dennis, both disconnects have to be together.

 

[kwired]

As others said disconnects need grouped.

You would be ok to just run service conductors straight from the meter to the house though, no EGC would be needed either in that scenario.

 

[westtx28]

Thanks. Regarding Kwired’s response that’s what I was getting at in my last sentence. So is it agreed that it would be made compliant by removing the existing OCPD and running 3-wire service conductors from the meter to the house’s 200 Amp panel with main breaker? (230.40 Exception 3)

 

[Dennis Alwon]

Thanks. Regarding Kwired’s response that’s what I was getting at in my last sentence. So is it agreed that it would be made compliant by removing the existing OCPD and running 3-wire service conductors from the meter to the house’s 200 Amp panel with main breaker? (230.40 Exception 3)

Yes that would be compliant although some inspectors may not agree--

 

[Carultch]

Couple of years ago customer had a 320 Amp service installed on side of shop building with the intention of servicing the shop with one 200 Amp panel and the option to add another 200 Amp panel to a separate future home structure. Forward to now home construction is starting and I’m looking at this and have some questions about the setup. Currently the shop has a 200 Amp with main breaker set on the back of the meter base inside shop. Meter base has second set of service entrance conductors going to a 200 Amp breaker set beside meter base. See picture customer provided from initial install.

Because there is an OCPD, I assume the conductors running to the 2nd panel to be located in the house are no longer service conductors but are feeders requiring a 4-wire feed. If this is the case where does the EGC run? To the bonded panel 1 EGC? Does this leave me with a disconnect grouping situation?

I understand what the original intent was but would it be better to propose to remove the OCPD and run a 3-wire service entrance feed to the 2nd panel? House is 200 feet away by the way.

I also notice that the installer drilled their own mounting holes, instead of using the hole locations that the manufacturer specifies.

 

[petersonra]

take the CB out of the box and use the box to splice in some service conductors to the new PB.

I think you will need SSBJ though.

 

[Dennis Alwon]

take the CB out of the box and use the box to splice in some service conductors to the new PB.

I think you will need SSBJ though.

Why would you do that? It is easier to remove the disconnect and not have a splice

 

[petersonra]

Why would you do that? It is easier to remove the disconnect and not have a splice

good point.

eta:

the black wire with the green tape looks smaller than #4 to me.

 

[westtx28]

Additional question on 320 amp service feeding two main panels that are in separate structures:
Assuming the following:
- Both PBs are feed with 3-wire service conductors from the meter.
- There must be an appropriate grounding electrode system at each structure.
- There are no metal pathways between the structures (water line, telco, low voltage, ect.)
Each panel’s neutral must be bonded to ground bus as in a single main correct?

I also notice that the installer drilled their own mounting holes, instead of using the hole locations that the manufacturer specifies.

I didn’t notice that. This is way out in rural dirt road TX. There are no inspections so it’s kind of a free for all out here.

the black wire with the green tape looks smaller than #4 to me.

Didn't catch that either. Looks like #6. I'll go back out later in the week and talk to owner.

 

[Dennis Alwon]

Additional question on 320 amp service feeding two main panels that are in separate structures:
Assuming the following:
- Both PBs are feed with 3-wire service conductors from the meter.

YES, Since it is a 3 wire to each building then the panels would be wired just as a service would be wired

- There must be an appropriate grounding electrode system at each structure.

Yes

- There are no metal pathways between the structures (water line, telco, low voltage, ect.)

Yes

Each panel’s neutral must be bonded to ground bus as in a single main correct?

Yes,

I didn’t notice that. This is way out in rural dirt road TX. There are no inspections so it’s kind of a free for all out here.

Didn't catch that either. Looks like #6. I'll go back out later in the week and talk to owner.

The #6 is probably going to the ground rod... not an issue

The metal pipe would have needed to be bonded but I assume you will remove that

 

[kwired]

I also notice that the installer drilled their own mounting holes, instead of using the hole locations that the manufacturer specifies.

Is that really a problem?

When mounting different sized items on strut like that it becomes difficult to get them all lined up without using a lot of strut and/or strut accessories. The meter socket shown actually has knock outs in the mounting holes, if you don't use them for whatever reason they are sealed. I would think it would be easier to punch those holes all the way out when manufacturing then to make them knockouts, maybe only a little easier though.

If you ran a strut horizontally across the bottom mounting holes the raceway KO in the back of the cabinet becomes blocked by the strut - about 99% of the time, OP would not have been able to come out the back side of the meter via the pre punched KO.

 

[westtx28]

Sorry to bring this up again. I went out and talked to the owner about his install and what would need to be done to proceed correctly. He is fine with the plan but out of concern on why it was originally done that way he had the installing electrician call me.


His point was because the second set of service entrance conductors don’t enter the building it is mounted on, the disconnect doesn’t need to be grouped. That grouping is only for each building served. He assumed the future house would be serviced with a 4-wire feeder sub-panel. He said, “like from a service pedestal.”


I’m reading through 230.70, .71, .72 and can’t see what disputes this. Now I plan to have the disconnect pulled and feed as standard service entrance as discussed but can you guys please help me understand where in the code the violation is. I just want a clearer understanding in case I talk to him again and for my own education.

 

[Glock23gp]

What's the question?

230.71 states there shall be no more than 6 disconnects.( You will have 2)

230.72 continues with the statement that they will be grouped together.

You have 1 service and 2 feeders.

The disconnects for those feeders need to be grouped at the service.

End of story.

Sent from my SAMSUNG-SM-T337A using Tapatalk

 

[Dennis Alwon]

Glock feeders don't need to be grouped. Your terminology makes it difficult to understand. There is a meter with 2 sets of service conductors , not feeders...

 

[kwired]

Glock feeders don't need to be grouped. Your terminology makes it difficult to understand. There is a meter with 2 sets of service conductors , not feeders...

What's the question?

230.71 states there shall be no more than 6 disconnects.( You will have 2)

230.72 continues with the statement that they will be grouped together.

You have 1 service and 2 feeders.

The disconnects for those feeders need to be grouped at the service.

End of story.

Sent from my SAMSUNG-SM-T337A using Tapatalk

There is one service supplying two disconnecting means, they are not grouped together (violation). So one service two feeders is correct. Service disconnects need to be grouped together, feeder disconnects wouldn't have to be, but a breaker can be both a service disconnect and a feeder disconnect.

 

[westtx28]

There is one service supplying two disconnecting means, they are not grouped together (violation). So one service two feeders is correct. Service disconnects need to be grouped together, feeder disconnects wouldn't have to be, but a breaker can be both a service disconnect and a feeder disconnect.

However,
230.40 Exception 3 states that a single service drop can provide one set of service-entrance conductors to each structure. So in this case there is one service but two service-entrance conductors, one for each structure.

230.71 states that there must be no more than six disconnects for each service permitted by 230.2, or each set of service-entrance conductors permitted by 230.40, Ex. 1, 3, 4 or 5. Doesn’t this mean that disconnects from one of the service-entrance conductors don’t count against the other when there are two?

So if that OCPD meant to serve the future house wasn’t there and the second set of service-entrance conductors ran all the way to the said house, all would be fine. No grouping violation. What’s the difference in that and the fact that in this case the second set of service-entrance conductors only runs a foot? And from there it becomes a feeder to the house. That is the case the original installer is making. I’m not saying there isn’t a violation here. I'm just starting to think he might be right in that it isn’t a grouping violation.

 

[Dennis Alwon]

There is one service supplying two disconnecting means, they are not grouped together (violation). So one service two feeders is correct. Service disconnects need to be grouped together, feeder disconnects wouldn't have to be, but a breaker can be both a service disconnect and a feeder disconnect.

Are we talking about the current situation or the situation of removing the outside disconnect on the building and going directly to the other structure from the meter? I was referring to the later. I thought we were clear that the present situation is a violation

 

[kwired]

However,
230.40 Exception 3 states that a single service drop can provide one set of service-entrance conductors to each structure. So in this case there is one service but two service-entrance conductors, one for each structure.

But the second structure is not service supplied, it is feeder supplied. You still have two service disconnecting means on the first structure and they are not grouped in same location.