ESTOP WO Delayed Vs Delayed
Why for VFD/Drives application E-Stop controller (CPU Relay unit, Safety PLC etc.) must have a pair of Immediate as well as pair of Delayed Outputs?
In short, the Reason being -- Immediate OPs asks the Drive to stop following the E-Stop ramp rate (not a Normal Stop ramp rate), and after a delay once the Drive achieves the "0" Speed -- the delayed OPs kills it's STOs (Safe Torque Off) thus makes it completely Safe.