mrbmcg
I thought you might find the following info useful in reference to variable speed on the Felder single phase multi machines. If you know all this already I'll get me coat
The 3-phase option is a inverter drive, which is a solid state frequency
drive. It turns single phase power into 3-phase with the ability to vary the
frequency, which allows for variable speed on the motors. The drive produces
true 3-phase power, it is always on and does not drop out like a static
converter would. The Felder machines do not work well or at all with a
static converter drive. The inverter is a great option and you have full
output of the motor as long as the inverter is rated for the load. The
Felder inverter is fully rated for 5 hp loads.
The motor on the single phase inverter system (5 hp) is the same 3-phase
motor as in the 5.5hp 3-phase configuration, on the inverter system the
motor is rated at 5 hp instead of 5.5. The 4 hp single phase is a 4 hp
single phase motor with no inverter, true single phase motor, it is a
similar motor to what the Italian manufactures call their 4.8 hp motor, but
Felder rates it 4 hp.
The inverter provides power all the time, and also gives the nice feature of
a soft start and dynamic braking. You have 5 hp all the time.
The pros of the inverter drive -
Single phase input with 3 phase motors
More power than a single phase motor
Ability to vary the speed of the motors
Silent operation, and easy hookup, just hookup 230 volt single phase to the
machine
Con the inverters are expensive and one is required for each machine, on
the Felder one inverter powers all the motors. If you had separate machines,
each machine would need an inverter drive.