Transformer sizing with non-continous loading

[lrob]

I have an application with 208 to 120 transformer single phase needed. I have 4 amps continous load, 2x 8.5 amp non-continous heater load and 7 amp non-continous heater load. The total amp draw is 28 amps. The non-continous is on for no more than 1 minute at start-up, the rest of the time it is PID pulsed on for less than 10 secs. Whether it matters this system is going to Canada. I thought I should be able to used a 3KVA safely. A second thought is that I wire the secondary for 220v and establish a grounded neutral on the secondary at X2 and X3 tied together. Then I would have 2 different 120v hots. Would this balance the load enough for me to still use the 3KVA. I could put a 5KVA on however I thought this would be unneccessary oversizing. Am I correct on this or am I overlooking some theory?

 

[lrob]

Scratch my thought on the split 120v secondary, I realized that was incorrect. 3 KVA is 3KVA no matter how I split the amps. So I still have the question on non-continous load rating on the transformer?