8C120

About the 8C120

The 8C120 is a part of the ImPak Plus series created by Reliance Electric. The drive deceleration time, the reference deceleration circuit ramps the speed reference input. The Ramp rate is adjustable by the DEC. potentiometer over 0.5 to a 30.0-second range. With the Drive in the “START” mode and running at one hundred percent speed, quickly turn the Operator’s Speed Pot to zero. Adjust the DEC. potentiometer to the desired deceleration time from maximum speed to zero speed for the machine and process. Keep in mind that the deceleration time cannot be any less than the coast down time of the machine. This drive does not absorb energy from the rotating machine, the only means of energy absorption is the frictional drag of the machine and process. For the linear deceleration, the set deceleration time must be set longer than the coast downtime. The Current (Torque) Limit (I LIMIT potentiometer) level of this drive is factory set to one hundred and fifty percent of the rated armature current. This value can be set to a lower value by adjusting the I LIMIT potentiometer on the Regulator board. Some applications require a lower torque limiting value so as not to damage the process material or the drive train. As a note when the current limit value is reduced, the available torque for acceleration is reduced. If tachometer feedback is to be used, set the IR COMP potentiometer to zero (fully CCW). When the drive is operated as an armature voltage regulator, as the processing load is increased, there will be an inherent speed droop caused by the inherent voltage drop in the motor which is proportional to the current.