Retail strip center service

Status
Not open for further replies.
O

OutletElectric

New member
Location
Cleveland, Texas, USA
Hello everyone, I need help! I am working on a bid for a retail strip center and the EE did not know what he was doing. I am trying to design the service myself and don't want to get it wrong. Details about the job are as follows;

12 individual leases 1600sf or so. total building is 20000sf.
Service is to be 120/208 3 phase.
The print shows 12 - 150 amp services with a total calculated load of only 440 amps (This cannot be right)
There is no overcurrent protection on the main service.
The house panel is to be 100 amp 3 phase.
The one line shows service entrance conductors coming into a 12 x 12 x 48 gutter with 12 individual meters tied into that.

For starters I'm not sure my load calculations are correct. I cannot find anything on demand factors for multiple non residential loads. I multiplied 150 amp service x 12 services at 80% comes to 1440 amps. I used this formula only because the EE showed a total demand of 550 amps x .8. Now because the service is over 1000 amps and has more than 6 disconnecting means, I should have a Main service disconnect right? There are so many things wrong on this print, I'm scared to bid it. I'm a small company that just got started a year ago. This will be the biggest job I've done so far and if I make a mistake it could end me.

Any help is greatly appreciated.
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
If you are bidding the project against others, you need to bid per the design documents.

Have the electrical drawing been reviewed by the AHJ?

If you just have the meters outside and run conductors to panels in each occupancy, there is no requirement for a main disconnect.
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
don_resqcapt19 said:
If you are bidding the project against others, you need to bid per the design documents.
Click to expand...

That can be a little tricky, since most drawings and specs also require that all work comply with applicable codes. I'd suggest issuing an RFI to have the EE answer any questions, and if he still claims everything is per code, then you can feel more confident that you won't be on the hook for changes the AHJ requires.

don_resqcapt19 said:
If you just have the meters outside and run conductors to panels in each occupancy, there is no requirement for a main disconnect.
Click to expand...

So each meter and disconnect is its own service? I've never been completely clear about multiple services at one location, and if the 6 disconnect rule applies.

Also, just because the EE figured 150 amp service for each tenant, doesn't mean that's the actual calculated load. 440 amps may be on the low side (I don't know anything that lets someone use a blanket 80% demand factor) but I'll bet 1440 amps is way high.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I agree with the others. Way too many variables come into play. Id tell whomever youy are quoting that you will be glad to quote the job based off engineered drawings approved by the inspection dept.
Anything other and you are opening up a whole can of worms.
 
I

Ingenieur

Senior Member
Location
Earth
using
550 A
208/3 ph
va ~ 200,000
or 10 va/sq ft or
does not sound out of line for retail space (without knowing the type of business or special equipment)

as long as everything is sized for 150 A / unit should be fine
at 80% that is 35 kva/unit or 20 va/sq ft

you would think the utility will size the service based on historical data for this type of facility
 
Status
Not open for further replies.
Top