commercial space calcs

[irelandnewyork]

Hi guys some help with a commercial installation would be appreciated i have a client that owns a 13,500 sq/ft space and is currently fixing it up there is an old 400a 3ph 3w system existing but not being used and a 100a single phase system which all of the building is currently running on and yeah the wheel is turning pretty hard lol. The building is quite old and only has one tennant at the moment and the rest of it is just general lighting and outlet no a/c units or heavy draw stuff at the moment. Without really knowing who or what is going to be renting the units there are about 4 all equal size would a 600a single phase systems with the ability to feeb 3 x 200a panels be a good starting point. I have done quite alot of 200a upgrades in houses but never any commercial stuff. Thanks for any help

 

[conmgt]

First, please post your question with complete sentences and punctuation. You're failing to use periods and question marks etc. I had to reread your post 3x to get your point. Probably why no one bothered to respond.

Second, you can, in no possible way, size a service without knowing the use of the space.

Third, 400A 3ph 3w as in no neutral? Please verifiy.

Fourth, stick with 3ph even if you put in a new service. You can subpanel into 1ph and you may need 3ph for HVAC or motors. 3ph will save on wire.

Fifth, 400A 3ph 208 is 144Kw and so is 600A 240V...give or take a few Kw.

 

[irelandnewyork]

Firstly. Sorry you had to read a few times it was late when i posted, if some people dont reply just because of that, i see that as there problem not mine.

Second. As i said the space is nearly all empty and this guy has no idea of who he will rent it to or what they will be doing when they move in.

Third. Yes 400a 3ph 3 wire no neutral someone put a ground on the side of the switchgear and they are using this as a return, highly dangerous i know.

Fourth. This would probably cost to much and the old 3 ph stuff is in pretty bad shape, thats why i suggested gettin rid of it and going single phase

Fifth. Even for general lighting is the load calc 13,500 x 3 as in 3w per sq ft and what about general recp

Sixth. Thanks for your reply

 

[quinn77]

seen this a million times...typical retail development

first, calculate general lighting
second, calculate receps at 6 foot intervals all the way around the tenant spaces.
third, calculate ac/heating load. consult ac professional if necessary.
fourth, calculate water heating, etc...
use art. 220 to determine required va
remember without proper planning and market research one can only guess what kind of potential tenants this place might attract. dont do building owners job, just calculate the basics and from there let the owner know what his options are. there are economical advantages and disadvantages to both single phase and three phase systems. also, if a potential tennant has some sort of design, the electrical will prob be designed by engineer so a required ampacity will be determined after design phase. if yours is too small, they'll look elsewhere. if it was my building, id pre-lease, then design.