“PF” is a fault message indicating that the motor has been drawing more amps than the current limit setting entered into the VFD. To clear this fault, the operator must issue a stop command from the keypad. The grinder will not restart unless the fault condition has been corrected.
The warning message “CL” is the precursor to “PF”. When the grinder is operated under a CL warning message for multiple seconds the “PF” fault will disable the grinder. See “CL” solution article.