Originally Posted by
drdfab
Just in answer to my own question if anyone is interested.... I called David from VMC Electric and he was very helpful in answering all of my questions.... Ok, so my VMC 15 has a 10HP closed-loop vector drive and the motor has a wye-delta configuration. It has a set of contactors which switch the motor windings between wye and delta namely at 2500 and 2501 RPM... (pardon any errors in my feeble explanation, hopefully the idea is clear) So I'm in 'high belt range' (1:1) I have RPM range of 0 to 7500 RPM. And in my control I select "SETP" then change "SPINDLE TYPE" to "7500 WYE/DEL" ..... Now my control knows where I have my manual range set so that the "S" word will correspond to the actual spindle RPM. So when the need for more torque comes, I manually change the belt to 'low belt range' (2:1) Now I have spindle RPM range of 0-3750 RPM. (The motor still goes 0-7500) Then I go into "SETP" and change "SPINDLE TYPE" to "3750 WYE/DEL" .... And now the "S" word which I input is correct with actual spindle RPM....
And then back to one of my other wonderments... What does "RPM FACTOR" in "SETP" do? Well, David told me that setting was for the models of VMC's which had only inverter drives on them (not Closed-Loop Vector Drives).... You could adjust that up and gain a little torque by compensating for 'electrical slip' in the motor.