Electrical Load Calculation - High Rise Commercial Building

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bragase

Member
Location
New York City
Occupation
MEP Designer
Hey all!
I did a load calculation for a 10 story office building in NYC. For every floor I have a different required load because they are all different in floor area. So I have, for example, for the largest floor 344A and for the 136A for the smaller floor (all 3 phases).

Every floor will be metered individually, so for the largest floor I will have a 400A meter and 150A for the smaller floor and so on.

I am now a little confused, should I consider the meter capaciy or the calculated load to size the main distribution panel?

Thanks a lot!
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It really depends if you want the customer to have the maximum use of their panels. You can size the service based on the calculated loads but it may be worthwhile going higher if there is a possibility of extra loads being added.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Usually POCO is Ok with any main breaker size equal to or smaller than the nominal service capacity. Which may be larger than the meter capacity. (A 320A meter base is good for 320A continuous but is OK for a 400A non-continuous in a panel with a 400A main breaker.
A notable exception is LADWP, which will not allow a larger than service size panel with a smaller main breaker to be used. Makes it hard to use 120% rule sometimes.

Sent from my Pixel 4a using Tapatalk
 

bragase

Member
Location
New York City
Occupation
MEP Designer
Usually POCO is Ok with any main breaker size equal to or smaller than the nominal service capacity. Which may be larger than the meter capacity. (A 320A meter base is good for 320A continuous but is OK for a 400A non-continuous in a panel with a 400A main breaker.
A notable exception is LADWP, which will not allow a larger than service size panel with a smaller main breaker to be used. Makes it hard to use 120% rule sometimes.

Sent from my Pixel 4a using Tapatalk
I am in NYC I will find out if the utility company here has any restriction to that. Thanks a lot!
 
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