Two services/One building

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TeslaElectric

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Larchwood, IA Sioux Falls, SD USA
A church expanding for the third time has 50kva 1ph 120/240V trans on the north side of building to a 200A meter socket supplying two 200A disconnects that are ~50' inside. One is a 200 main breaker with 60A subpanel and the other is a fused disconnect that feeds a MLO panel across the building. They put a walkway with fire doors to attach the first addition so they could put a 75kva 3ph 120/208V trans on the south side of building supplying two 225A panels through a 400A CT cabinet. Right now there is a 30x75 unattached garage going up for the buses to park. I am going to put 100A panel in there from the single phase service. Next spring they want to add on 20,000 sq.ft. attaching to north side with calculated load of 200A not including 2 of the 4 A/C units because they are 3ph. i asked the HVAC company to get me specs on single phase units and they dont make 7 1/2 ton units single phase i guess.. the utility company wants me to eliminate the single phase service and refeed it with 3 phase from the south. they passed inspection because of the fire doors and now have two addresses and pay two bills to the power company. it is 500' from the CT cabinet on the south side to the north side meter going all the way around the back of the property. some of which will be under the future addition. do i eliminate the single ph service? inspector wont let me feed future addition with 3 phase from south because it is attached to north part of building. if i refeed single phase service with 3 phase how do i balance the load as best as possible? i will have two 200s and a 100 from there.

any tips would be appreciated.. trying to stay sane. And i have not checked all the single phase 240V loads yet to see if they will work on 208..
 
Smart $

Smart $

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Location
Ohio
Welcome to the forum, TeslaElectric. :thumbsup:

Sounds like the most imminent problem is the inspector... and it appears he is easily coerced by the POCO. He should permit 208Y/120 3Ø 4W from the south for the new addition based on two key points: 1) dissimilar characteristics, and 2) facility is large enough to require more than one service. I would work this "angle" before doing any other planning...!!!
 
iwire

iwire

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I have a different take on it.

Here the power companies do not wish to, and in most cases will no longer provide multiple services to the same building. So regardless of the NEC we would be refeeding the old service from a new one.
 
Smart $

Smart $

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iwire said:
I have a different take on it.

Here the power companies do not wish to, and in most cases will no longer provide multiple services to the same building. So regardless of the NEC we would be refeeding the old service from a new one.
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What if two services already exist? OP did not mention having to upsize either existing transformers for the new addition.
 
iwire

iwire

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Smart $ said:
What if two services already exist? OP did not mention having to upsize either existing transformers for the new addition.
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In the small sizes the OP is dealing with my experience is that they would have us re-feed the existing from the new.
 
Smart $

Smart $

Esteemed Member
Location
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iwire said:
In the small sizes the OP is dealing with my experience is that they would have us re-feed the existing from the new.
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Yes, there is a good chance the 3Ø service will require upgrading...

...but I was asking as if there was not going to be any new service or upgrade of the existing? Do you see any reason for the inspector to not allow supply of the new addition from the 208Y/120V 3Ø 4W service from the south?
 
iwire

iwire

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Staff member
Location
Massachusetts
Smart $ said:
...but I was asking as if there was not going to be any new service or upgrade of the existing?
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If there is a small service on a building today in my experience the local power companies will not provide a second service to it.

So it seems the OP has a single phase service now and wants to add a second service for three phase. In my experience the POCO would tell us the single phase service will be removed and we will have to run a feeder to it.

Do you see any reason for the inspector to not allow supply of the new addition from the 208Y/120V 3Ø 4W service from the south?
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No I do not, I see the NEC allowing it. :)

The inspector may know the POCO will not provide it though.



(Edit: To be clear, I am not saying my experience applies to the OPs power company, they are all different)
 
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TeslaElectric

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Larchwood, IA Sioux Falls, SD USA
they didnt like leaving the old service there to begin with. the inspector will not let me bring 3ph to addition because its being attached to the north side of the building which has the 1ph.. if the future addition was being attached to the south side there would be no prob.
sorry forgot to mention 1ph service will be upgraded to a 75 or 100kva trans to suffice the garage and future addition if that is how the customer wants to spend the money.
so do i try to convince the hvac installer to get 1ph RTUs or just tell him there isnt 3ph availabe so too bad so sad? ha. he said he can only get 5 ton units and these 3ph ones are 7 1/2. they are not ordered. just quoted. i would prefer to upgrade the 1ph service bc it will cost the least and the simplest for everyone... the power company said they would not go any bigger than 100kva on the 1ph trans and i think it would be marginal for the a/c load.
 
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TeslaElectric

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Location
Larchwood, IA Sioux Falls, SD USA
and if i were to refeed the 1ph with 3ph that would be like parallel 400 Al or 750 copper or something crazy like that . i did recently watch mikes video about terminating wire in a jbox with 90*C terminals next to breaker box so the feeders can be run according to their 90*C ampere rating through the raceway that will be 500' maybe save me one wire size and a few pennies
:sick:
 
Smart $

Smart $

Esteemed Member
Location
Ohio
iwire said:
If there is a small service on a building today in my experience the local power companies will not provide a second service to it.

So it seems the OP has a single phase service now and wants to add a second service for three phase. In my experience the POCO would tell us the single phase service will be removed and we will have to run a feeder to it.

...
Click to expand...
Seems like you are stuck on something being new. :(

The site already has two services: 120/240V 1Ø 3W AND 208Y/120V 3Ø 4W.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
TeslaElectric said:
...
sorry forgot to mention 1ph service will be upgraded to a 75 or 100kva trans to suffice the garage and future addition if that is how the customer wants to spend the money.
...
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If the 120/240 service is refed from the 208/120 service, will the transformer have to be upgraded? If yes, at customer's expense?
 
kwired

kwired

Electron manager
Location
NE Nebraska
Smart $ said:
If the 120/240 service is refed from the 208/120 service, will the transformer have to be upgraded? If yes, at customer's expense?
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Customers expense can vary from one POCO to another. Most around here the customer will not be paying the cost of the transformer and equipment outright, but rather a cost that considers amount of return on energy sales.

Church loading can vary quite a bit. Some have activity nearly every day, others just a few hours on Sunday and maybe an occasional event here and there during the week. The ones that have activity nearly every day and more regularity to the energy use may get their service installed for less cost then one that requires same equipment but only has a peak demand once or twice a week.
 
T

TeslaElectric

Inactive, Email Never Verified
Location
Larchwood, IA Sioux Falls, SD USA
POCO said they will sell them CT cabinet and wire of existing service. they will also upgrade 3ph trans, hopefully CTs inside so the customer wont have to buy another, more expensive cabinet. im optimistic that i can get this all done before the ground starts to freeze. the POCO wants to wait until next spring. the general wants it done on tuesday. he talked to the hvac installer who also does boring and that sounds good to me. less trenching, less time.. the general is also my father-in-law and attends this church.. ugh
 
Smart $

Smart $

Esteemed Member
Location
Ohio
iwire said:
Already mentioned by yours truly back in post 7.

Please share your experiances of telling the power company how things will be. :D
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Another time. The OP's situation is all that matters here. I have not lost sight of that, and that's all I'll discuss. From what I gather from the OP's posts, the church's POCO is willing to upgrade either service (he'll correct me if I'm wrong), but they have made it known their preference is to supply the entire premises with 208Y/120. So why don't you get on board and answer some of the OP'ers questions about upgrading one versus the other, etc.
 
kwired

kwired

Electron manager
Location
NE Nebraska
Smart $ said:
Q1: Will the POCO upgrade the 120/240 service as needed?

Q2: Will the POCO upgrade the 208/120 service as needed?
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Q3: Will they upgrade both or do they leave you with a choice of keeping one or the other?

So far it appears it is just their preference to supply just one service, but not absolutely the rule.
 
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