Main switch sizing for 3-Phase/RPC input.

I just installed a main ON/OFF switch which starts my RPC and, consequently, 3-phase distribution in the shop. The switch is installed directly from the main box for the building. From the switch, the lines proceed to a smaller breaker box. The third leg generated by the RPC is also connected through the same breaker box. That means, the output from that breaker box is the source for all 3-phase wiring (4 machines) in my shop. Here are the components:

McMaster item number 6759K35 - High-Amp switch.
Phase-A-Matic R3, 220V 1-phase input. Rated capacity is 3HP.
Each breaker on each line of the three phase output is rated 15A.

Did I size the switch correctly?

I was working off of the overall amperage rating (32A @ 600VAC). Now I notice these "horsepower" ratings which have me double guessing myself. It makes no sense to me why a 32A switch would only be rated for two horsepower, 240V, single-phase. A 2HP single phase motor would never pull 32A anyway, right?

If I recall correctly, the paperwork for my "semi-pro" RPC, 7.5 hp, called for 60A capable supply wiring and devices. It must be calculated based on an assumption that it will be started under a full load of also-starting 3ph stuff.

(RPC made by an electrician as a part-time biz, but not a "commercial product"...)

Chip

Here is the specifications as shown in my RPC manual: Phase-A-Matic, Inc. Rotary Phase Converter Installation Instructions "Minimum Single Phase Supply" is listed as only 20A. Truthfully, I almost bought the smaller sized switch from McMaster, but the step up to 32A size was less than four dollars more, so I figured, "why not?".