Disconnect sizing

Hello everyone, great site as always. When it comes to sizing a disconnect for a motor control panel, I have seen several websites with many different answers. The most common answer that I found is to size the disconnect 115% greater than the total FLA of your motors. Is this true? I have an application, small panel, with two VFD's and a PLC. They will be controlling 2 7.5H.P 480VAC motors. So just a summation of the FLA between the 2 motors, and multiply by 115% for my main disconnect? (of course also taking into account for other circuitry in the panel.).

TIA for the help,

Greg

Paraphrasing UL 508A sec 30.3.3 for a molded-case switch it should be not less than 115% of the FLA ratings of all motors plus the full load current of all other loads

and

the locked rotor current of the switch shall not be less than the sum of the locked rotor currents of all motors plus the full load current of all other loads