Question? There is a 200 amp 240/120 volt single phase service. This is an exsiting service on a small restaurant. Existing service has an A/C unit and Air Handler with Heat strips. 2 light circuits and 1 Rec. circuit with 4 outlets on it. 1 sign circuit. How do I come up with the existing load calcuation for the service? And have to add additional another ac unit, air handler, HWH, 15 kitchen circuits and general recs and lighting etc.
What method do I use to get the existing load and what calcuation in the code do I use to determine to new service size?
Check out 220-36 of the 2002 NEC - it sounds as though you may qualify as a "new" restaurant and will be able to use this shorter calculation. You will have to determine the total connected load - including heating + cooling - that's everything using electricity - add all new equipment with nameplate ratings and go to the table to find your demand factor. This eliminates the use of part II of section 220 which could cause you grief. I would add a few amps for that unforseen appliance that they didn't tell you about. Good Luck