Xylem IM255 AQUAVAR Intelligent Pump Controller - Manual (Page 42)

* To use a voltage signal from the PLC/BMS, configure parameters 6-20, 6-21, and set
switch A54 to U.
Duplex control wiring
The controller can be configured to operate in a duplex control system having 2
controllers and 2 variable speed pumps. In this configuration pumps can be staged and
destaged as needed and the lead pump can be alternated. When both pumps are on they
operate at the same frequency. To configure the controller for this type of system, a
specific wiring configuration is required. The diagram below shows the wiring required to
implement the duplex control system.
Figure 26: Duplex wiring
Duplex Control Mode requires a specific set of parameters in order to ensure proper
functionality. The Start-Up Genie must be used to configure the Duplex Control Mode.
See the Commissioning section for details.
Control from external PLC/BMS through communications port
A BMS or PLC can be connected to the control through the communications port. In this
configuration, the BMS or PLC can control the drive by overriding the setpoint, supplying
the process variable or by providing a speed command to the drive. Control cables must
be braided screened/shielded and the screen must be connected by means of a cable
clamp at the controller and at the BMS/PLC. Refer to Using Screened Control Cables for
Electrical Installation
40 Aquavar ® Intelligent Pump Controller INSTRUCTION MANUAL