Service Calculations

[eds]

I have not had to size a service with these loads in a long time, so please check this over

480 volt service with the following loads ( no specs yet just verbal from the hvac guys

(2) chillers with 150 amp MCA each three phase 480v

Each chiller has (4) evaporater fans rated flc 0f 25 amps @240 single phase ( hope these will be rated for 208 also

Misc 208/120 loads consiiting of some lighting and small 5 gal electric water heater

I plan on using (2) 75 kva 480v/208/120 transformers

I took the 150 amp chiller load times 175% based on 440.22A plus the additional 150 amp chiller, plus the 2 75kva transformers giving me a ending value of 493kva/480*1.732 or 593 amps

Does this look like I am on the right path (again it has been awhile)

Thanks

 

[Smart $]

Your chiller loads are determined by 440.6, which would be 150A each.

Your lighting load minimum has to be initially determined per Table 220.12 for the occupancy type and areas.

Seems to me there will be more loads than just the mentioned items...

Without performing a calculation per Article 220, there is no way to tell for certain that your service is properly sized.