If only legs A and C are being used like in this case. Dosent this technically mean this is a single phase system? and the load calculations should be based on single phase not 3 phase?
If you are only using A and C legs, then it is single phase and you do single phase load calculations, which then apply only to the A and C legs. If you are doing a new service, then you wouldn't even need to install the B leg.
Unfortuanly no. The A/C's are single phase and the rest of kitchen equipment is single phase but with neutral, so i cant use double poles on the high leg either. I'm just going to use A and C phase since that is all i have.
If you have a straight 240V single phase load (no neutral), you can connect it between B and A or C. When you use only 2 terminals of a 3 phase system, then load is fed with single phase power.
There are two significant cautions on this approach: some loads that don't use the neutral still like their 'hot' legs to be balanced with respect to ground, and most double pole 240V breakers are only rated for 120/240V single phase, so you need to find special breakers _or_ just use 2 legs of a 3 pole breaker.
If you don't need 3 phase power, then I agree it would probably be simplest to get rid of it. Since all of your loads are single phase, the only reason you might need to keep the 3 phase is if your load calc requires more kVA than the single phase can handle.
-Jon