Service from utility terminated in enclosure with 2 mains. One main would feed 6 meters and the other main would feed one meter...Is this allowed?

V

Volt-Amps

Member
Location
Indianapolis
kwired said:
Where does the second breaker go when used. Doesn't look like the cover has any place for a second one but maybe there is details we can't see or modifications needed that are not obvious in this image?
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This is the existing setup. The discussion is about the possibility of changing this section with one main and replacing it with incoming service section that has 2 mains (400A and 200A)
 
kwired

kwired

Electron manager
Location
NE Nebraska
Volt-Amps said:
This is the existing setup. The discussion is about the possibility of changing this section with one main and replacing it with incoming service section that has 2 mains (400A and 200A)
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So just changing the main power section of a modular meter system it sounds like?

I don't know about Eaton, Square D likely sells to you at better pricing if you order a so called complete setup and not just one module. Like purchase the mains module and at least one meter module instead of just the mains module only. I guess something to ask your distributor about just in case.

Also why not just go with a single 600 amp main instead of a 400 and a 200? Or does one main feed say the left bus and one feeds the right bus? The bus about needs to be rated 600 amps if it is capable of doing the single 600 amp main anyway.
 
V

Volt-Amps

Member
Location
Indianapolis
Thank you gentlemen for your help. Given space limitations and other factors, landlord agreed to provide separate 3 phase service for the retail space.

I appreciate all your responses and valuable input from all.
 
D

david

Senior Member
Location
Pennsylvania
Volt-Amps said:
I may have miscommunicated what I want to do, but thee intent is to upsize the existing feeders to 600A from 400A. Adding another set of 3/0 should do, depending on how many lugs or landings we have, which I suppose should be OK.
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And like already said that is perfectly fine to make your service entrance 600 amp and it sounds like that is the direction you want to go in

But what was being said is you do not have to do anything at all to what is existing, you could choice to leave it completely alone.
You could take a 200 amp service entrance to a 200 amp service disconnect installed right beside your existing 400 amp service disconnect and the 400 amp and the 200 amp would be grouped together.

It dosn"t matter from an NEC prospective go ahead and increase the existing from 400 amp to 600 amp

Never mind just read post #25
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
david said:
So in other words it makes no difference to the NEC which way it is done
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No, it does make a difference. We don't know if there are service conductors between the service point and the place the OP wanted to put a wireway and tap. If there are, then whether those conductors can be reused depends on the total load calculation.
 
D

david

Senior Member
Location
Pennsylvania
jaggedben said:
No, it does make a difference. We don't know if there are service conductors between the service point and the place the OP wanted to put a wireway and tap. If there are, then whether those conductors can be reused depends on the total load calculation.
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I agree in principle what your saying. The OP said he was going to add a new set of 3/0 to what was suppling the 400 amp service. That implies that the existing service is two sets of 3/0 assuming the OP understands he would have to parallel these three sets together.

The op daid:

" I may have miscommunicated what I want to do, but thee intent is to upsize the existing feeders to 600A from 400A.

Adding another set of 3/0 should do,

depending on how many lugs or landings we have, which I suppose should be OK. "
 
D

david

Senior Member
Location
Pennsylvania
jaggedben said:
No, it does make a difference. We don't know if there are service conductors between the service point and the place the OP wanted to put a wireway and tap. If there are, then whether those conductors can be reused depends on the total load calculation.
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Unless the 400 amp service has no actual history the nec is no longer concerned with the calculated load of the 400 amp service.

You can present actual data from a utility that will show the max usage through out the year or a couple of years.

There is no difference in three of the options that were presented in this thread in how calculated load is addressed.

You have to have an over all supply large enough to Handel the load.

400 amp service increased in size to handel the load

400 amp service left alone
Additional service entrance installed sized for the new calculated load grouped same location

400 amp service left alone a thee phase service installed at another location sized based on the additional calculated load

It makes no difference in which option you use in adding a calculated load to an existing building

In principle I understand why your emphasizing the total calculated load
 
D

david

Senior Member
Location
Pennsylvania
Another option would be to present actual known data from a utility and show the 400 amp service is large enough for the existing load and the additional calculated load.

For an existing building the total calculated load can be considered but really is not the determining factor in allowing a new load to be added to an existing load
 
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
david said:
.

There is no difference in three of the options that were presented in this thread in how calculated load is addressed.
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Yes there is . Where service conductors feed multiple service disconnects, the conductors are sized to the load. Where service conductors feed a single disconnect, the conductors must also be sized to the ocpd they are feeding. Another difference is you likely get more diversity, in practice and in the calcs, when you have a single set of conductors serving everything.
 
D

david

Senior Member
Location
Pennsylvania
electrofelon said:
Yes there is . Where service conductors feed multiple service disconnects, the conductors are sized to the load. Where service conductors feed a single disconnect, the conductors must also be sized to the ocpd they are feeding. Another difference is you likely get more diversity, in practice and in the calcs, when you have a single set of conductors serving everything.
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I didn't say there was no difference. I said in how the calculated load is addressed
 
D

david

Senior Member
Location
Pennsylvania
electrofelon said:
Yes it's different. If an additional parallel was added to the 400, the entire load, including any new load, would be calculated. If a new set were added, just the new load that set is serving would be considered.
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There is no diferance in what your saying.
If you have an existing load on a 400 amp service and calculate a new load and determine an addition upgrade of 200 amps or less is sufficient for the total existing load on the 400 amp plus the additional calculated load your adding.

There is no difference at all in how you distribute that load based on the totaload the building service would have to be sized to Handel.

No there is no difference at all when it comes to supplying the total load

It is simply a design choice nothing more
 
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
david said:
There is no diferance in what your saying.
If you have an existing load on a 400 amp service and calculate a new load and determine an addition upgrade of 200 amps or less is sufficient for the total existing load on the 400 amp plus the additional calculated load your adding.

There is no difference at all in how you distribute that load based on the totaload the building service would have to be sized to Handel.

No there is no difference at all when it comes to supplying the total load

It is simply a design choice nothing more
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I suggest you reread post #35. Sure is probably a relatively small difference for the size services we are talking about but nonetheless there is a difference
 
kwired

kwired

Electron manager
Location
NE Nebraska
david said:
There is no diferance in what your saying.
If you have an existing load on a 400 amp service and calculate a new load and determine an addition upgrade of 200 amps or less is sufficient for the total existing load on the 400 amp plus the additional calculated load your adding.

There is no difference at all in how you distribute that load based on the totaload the building service would have to be sized to Handel.

No there is no difference at all when it comes to supplying the total load

It is simply a design choice nothing more
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I think the point is that if one looked at demand history and it were low enough it may be possible to add the new load to the existing 400 amps of service conductor, keep existing 400 amp main and add the additional 200 amp main.
 
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