Xylem IM255 AQUAVAR Intelligent Pump Controller - Manual (Page 74)

Speed control
Speed Control Mode allows the speed to be controlled by an external device such as a
PLC or BMS. A start signal on DI 18 is required to start and stop the pump.
To configure Speed Control Mode first select the speed reference source. Select the
speed reference source as either an analog input or, if using the fieldbus as the speed
reference source, select No Function. When using the analog inputs be sure to set the
analog input configuration switches to the appropriate feedback type. Refer to the Analog
Input Configuration (Switches A53 and A54) section for details on setting the analog input
configuration switches. Refer to the Common Terminal Wiring Configurations section in
this manual for detail on wiring external devices to the analog inputs.
Next set the minimum and maximum reference/feedback values. The Low Ref./Feedb.
Value is the speed value that corresponds with the low current (0 or 4mA for current
references) or low voltage (0V for voltage references) that will be applied to the analog
input. The High Ref./Feedb. Value is the speed value that corresponds with the high
current (20mA for current references) or high voltage (10V for voltage references) that will
be applied to the analog input. For example, if the application uses a 4-20mA reference
signal on AI 53 and the pump is required to operate from 30Hz to 60Hz, set [6-14]
Terminal 53 Low Ref./Feedb. Value to 30 and [6-15] Terminal 53 High Ref./Feedb. Value to
60.
The minimum and maximum speed reference values are set next. These values are the
minimum and maximum speed settings for the application. These settings will limit the
controllable speed range of the pump. The speed range will be limited to the Minimum
Speed Reference as the low speed limit and Maximum Speed Reference as the high speed
Operation
72 Aquavar ® Intelligent Pump Controller INSTRUCTION MANUAL