WJ200 Free run commands
Free run always active, should program both B091 and B088 as follows:
B091 Stop mode selection = 01 free-run to stop
B088 = 01 Resume from current speed
Or program an input function to give the free run command, so C162-C166 (Inputs 3-7)
11 FRS Free-run Stop = ON input , allows motor to free run (coast) to stop
I often use the latter with a micro switch if one wants to use the machine mechanical brake. So when you hit the mechanical brake, it closes a micro switch which engages an input to give the free run command. If using electronic braking, you can push the VFD a little harder on the braking on a mill without an external braking resistor, because there is less mass (momentum) in the system. Not sure what happens when you start spinning the mill at very high RPM. If one brakes too fast, normally you would get an over voltage error on the bus, because the buss voltage exceeds the programmed threshold which is adjustable to a point. The other factor, braking resistors are cheap, so if you plan on using electronic braking, just get a resistor. Haven't seen a choke used for braking, more for smoothing the ripple on the bus or to tame the voltage switching spikes. Using a braking resistor will keep the VFD cooler, since it will not need to dissipate all the system energy internally, which = heat which is not good long term. Have also used the free run command for tapping on a lathe, and also tied to the lathe mechanical brake. Lots of possibilities.
Mark