PID settings

Path: Main > Set Group PID

The Proportional plus Integral plus Derivative (PID) loop controls the output of the fans.

Caution: This procedure is to be performed by APC authorized personnel only. Improperly set PID controls could result in equipment damage.

There are two sets of PID coefficients stored in the unit. One set is used when the unit is programmed for Spot (Proportional) mode and the other set is used when the cooling unit is programmed for InRow mode. Only one set can be active at a time. The active PID set is determined by the value of the Type and Capacity Ctrl properties (Path: Main > Configure Group). The active set can be read, written or set to default.

Gain (P). The proportional multiplier (gain) for this mode or actuator. The proportional multiplier adjusts for the difference (error) between the measured value and the setpoint.

Rate (I). The integral multiplier (reset rate) for this mode or actuator. The integral multiplier adjusts for error measurement and the amount of time that the error has existed. The integral multiplier adds to or subtracts from the output in small increments to correct for the offset error caused by the proportional contribution.

Deriv (D). The derivative multiplier (derivative) for this mode or actuator. The derivative multiplier adjusts the output for rapid changes in the error, correcting for the rate of change of the error over time.

Reset to Deflts (InRow or Spot (Proportional) only). The Gain, Rate and Derivative coefficients return to their default values.

20

InRow RD 10 kW Air Cooled Operation and Maintenance

Page 28
Image 28
APC ACRD100, ACRD101 manual PID settings