10 amps is too low of a fuse for a 7.5 hp rpc on 240 v.
Phase a matic says 40 amp time delay fuses for a 7.5 hp on a NEMA size 1 contactor for 240 v operation.
if you were to install an overload on the contactor it would need to be set at 26 amps
it is common for a RPC to run warmer if it is not balanced.
is the phase a matic's third leg on a momentary switch? if is not it should be when it's utilized for a pony motor if you are using a static converter .
you want the phase a matic static converter only to start the pony(slave) motor then the rpc will run unassisted from the singe phase input.
if the phase a matic's third leg is left in circuit,
the phase a matic static converter will inject a DC pulse from the start capacitor contained inside the unit, any time voltage dips below a preset level.
this is a bad thing when trying to start other motors from the pony motor and may be a factor in the problem you are experiencing.
it has the tendency to want to start the next motor in line in reverse.
when a phase a matic is used without a pony motor and hooked directly to the intended 3 phase motor, the DC charge is going directly to the motor it is driving and you would not have to consider any ramifications of starting a second motor.
i'd be happy to help instruct you to get er done, should you need a hand .
i hope the information helps out
