Service design for tenant fit-out buildings

[dahualin]

Our client, a developer, who wants build two buildings on a proposed land. One building is a tenant fit-out building (the shell) that has seven units. The other is a bank. Our client wants only one service (one transformer) from utility company. My question is if I can connect two service cables to the transformer, one for the tenant fit-out building and one for the bank. If not, do I have to use a trough in one electrical room to tap the service cable for the other building? Both buildings will have their own electrical room inside their buildings.
For the tenant fit-out buidling, since eight electric meters will be installed, seven meters for the seven units and one meter for site lighting, I have to use a MDP (Main distribution Panel) before those meters for power distribution.
Any different approches are really appreciated.

David

 

[petersonra]

Since you don't know what is going to be in these spaces, how do you plan to calculate the required load?

 

[hmspe]

Since you don't know what is going to be in these spaces, how do you plan to calculate the required load?

What we do in my office (mostly Arizona projects) is use 30 to 50 VA per square foot, depending on what we expect the tenants to be. 30 would be for office. 50 will cover most restaurants. We do shell buildings this way all the time.

Martin

 

[hmspe]

My question is if I can connect two service cables to the transformer, one for the tenant fit-out building and one for the bank.

I suggest you ask the utility. Their policies vary. Also, it will depend to some extent on what the ampacities of the services are.

If not, do I have to use a trough in one electrical room to tap the service cable for the other building? Both buildings will have their own electrical room inside their buildings.

See NEC 230.3. With interior electrical rooms the answer is no.

For the tenant fit-out buidling, since eight electric meters will be installed, seven meters for the seven units and one meter for site lighting, I have to use a MDP (Main distribution Panel) before those meters for power distribution.

That would depend on where you are in the country. In the Phoenix the meter has to come before the tenant disconnect (a main is allowed before the meters). What's commonly used for this type application is something like: http://ecatalog.squared.com/catalog/173/html/sections/09/17309004.html#1009290


If you haven't done a project like this before I'd suggest finding someone in your area who has to help.

Martin

 

[bob]

This is not complex. With the approval of the utility you have them install
ct's in the transformer secondary cabinet so that both service laterals are metered with one meter.

 

[iwire]

This is not complex. With the approval of the utility you have them install
ct's in the transformer secondary cabinet so that both service laterals are metered with one meter.

We do not do that here.

Many of the local utilities will not put the CTs in the transformer.

Besides the tenants / landlord will need / want their own individual metering.

 

[sceepe]

My question is if I can connect two service cables to the transformer, one for the tenant fit-out building and one for the bank.

Yep. The POCO will have a limit of how many conductors they can connect to sec phase of their xfmr secondary. The number varies by xfmr size. You should be able to run a couple of sets to the strip mall and one set to the bank.

I would go with the multi meter pack that martin was talking about for the strip mall. A word of caution. Some meter packs have a built in main breaker for each tenet after the meter. I recently ran into a one with a maximum 250A breaker. This was too low for the restaurant that wanted to up fit the space.

 

[steve66]

One service is not the same thing as one transformer. You can probably get the utility company to set one transformer, and run two services out of it with two separate meters.

I don't think you can tap a service. I don't think the NEC allows it, and I don't think the utility will allow it.

Around here, you can't put a disconnect in front of the meter. The power company (POCO) dosen't want people to shut off the power where they can tap into it unmetered.

One of the things that should be considered is the posibility of the two building getting sold to different people. Then you don't want one service coming out of the other building.

I would contact the utility and work with them.

Steve

 

[charlie b]

I should think that a bank would have special requirements related to its electric service. I don't think they would want to share a service with another building. If anything happened to the other building's service conductors, for example, such that the transformer would have to be de-energized during the repair, the bank would be dark or be on its own generator. I have no facts or experiences to offer on this issue. But I think it is worth some consideration.

 

[iwire]

Charlie I am sure that can depend on the bank and if it's a main branch or just a small one.

A lot of banks build on a very tight budget...you know they really don't have any money.

I have been involved with quite a few banks that derived their power from someone else's switch gear.

When I have to do major service I end up 'dumping' the banks as well.

Sometimes I warn them ahead of time.

 

[dahualin]

Thank you very much for your help. I think I know how to approach this project right now.

David