Emerson VISSION 20/20 service manual Other Setpoints That Might be Required for Motor PID Control

OTHER SETPOINTS THAT MIGHT BE REQUIRED FOR MOTOR PID CONTROL

•Max Change Rate = The VFD motor PID output is limited by this parameter to prevent large instantaneous changes to the motor speed.

•Dead-band= used to establish a range on either side of the set-point in which no capacity control action will occur. Initial Setpoint: 2.5%

•Min Spd Point = used to prevent the compressor from running too slowly which can adversely affect hydro- dynamic sealing, heat transfer and lubrication. Initial Setpoint: 50%

•Setpoint Ramping Rate = used to control how fast the compressor responds to the required capacity control action. Initial Setpoint: 20 Unit/min

•Unloading Rate = used to control how fast the unloading action occurs due to a safety override. Initial Set- point: 20%/min

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