# Three office trailers service



## kevin1005 (Jun 16, 2018)

I'm pricing a job for a customer who has 3 Office Trailers. I'm taking over from an electrician who has since disappeared and isn't returning phone calls...

The power company said they had planned on installed a 120/240V 320A service as this would be direct and doesn't need a CT Cabinet. The problem I'm having is confidently saying that is large enough to handle the load.

*Each trailer has a separate 15.6 KW Heater/AC Unit, translating to 195 Amps*The other remaining loads are 2KW HW heater in each unit, lights, dedicated outlets, bathroom fans and general use outlets.*These are going to be offices, and off of the generic trailer plans I have to go off of the KW loads are 27.9, 27.2 and 30.7= 85.8KW*

Based off of 230.42, it seems that I should be taking 100% of the KW rating to size my service which would put me at 357A= 400A service.

*But thinking this out, even with all three heaters running, we would still have an extra 125 Amps to spare on each phase, I feel like that is enough ampacity to handle the lights and general use outlets for an office of 10-15 people.*
What is your opinion on this? Is there a different calculation I am missing? Thanks in advance.


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## Cow (Jan 16, 2008)

I think you'll be just fine.

It's a diversified load, how often is everything going to be running at full load? In my experience dealing with offices? Never.


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## kevin1005 (Jun 16, 2018)

Thank you for the reply, that was my thought as well, but then I was reading online about how poorly the trailers are insulated and that the heat demand would almost be continual during a cold snap.... It got me worried. I don't want to size it wrong.

It involves a 300 foot wire pull, and I need to be right on this.


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