Short Circuit / Coordination Study

The HVAC condensing unit will be powered by induction motors (compressor and condenser fan typically). Without knowing what the power factor will be, a reasonable assumption is 0.80. 11kVA x 0.80 = 8.8kW. In turn, 8.8kW/0.746 ≈ 11.8HP.

The heater has a PF of 1.0, so 36kW = 36kVA. Converting to HP sounds a it odd, but 36/0.746 ≈ 48.3HP.

For a coordination study, it would seem that kVA (and then amps at the voltage in question) would be the best common units to use.

I wanted to convert it to HP to signify the load for each of the lines. Am I doing something wrong? Is there another approach?

I was also told that items that have no "stored energy" do not need to be shown on the one-line to do the simulation. However, again I have no basis or known facts to back that up.

I don't think you're doing anything "wrong" exactly, but it seems to me that KVA and amperes are the logical units to which to convert from other units. Somewhere in the whole study you would be looking at peak let-through current and maximum let-through energy of the fuses and/or circuit breakers to be coordinated. These devices are not rated in terms of horsepower. I am not familiar with the term "ETAP".

All of Tornado's comments are totally valid, but a short circuit study is actually driven by the energy source.

You need to contact your power supplier to get the available short circuit power at your connection to the grid.

Usually, these values will be "reasonable" but some times they can be extreme. The value of the short circuit analysis is to determine if all connected devices are capable of action in the event of a major short circuit. Typical short circuit amperage levels are relatively low- 24,000 to 36,000 amps- but you need breakers rated for the appropriate level to be sure that they can clear a short rather than be fused closed by an arc if they try to snap open. I once worked on a system that was a 208 VAC- 3 phase network in a downtown area that was fed by 5 different power plants- each of which was connected to several transformers that were connected in parallel on the 208 VAC low voltage side. This system had a short circuit potential of 200,000 amps and needed special breakers for all "primary" power feeds from the distribution panels as well as secondary breakers rated for 64,000 amps downstream or the high-rated main breakers in each distribution panel.