Sensor port
The Sensor (SA Bus) port on the left side of the FX-PCV (Figure 2) is an RJ-12, 6-position modular jack
that provides a connection for the VAV Balancing Tool, specified network sensors, or other SA Bus
devices with RJ-12 plugs.
The Sensor port is connected internally to the SA Bus terminal block. See Table 5 for more
information. The Sensor Port pin assignment is shown in Figure 5.
Figure 5: Pin number assignments for sensor, SA bus, and FC bus ports on FX-PCVs
Supply power terminal block
The 24 VAC supply power terminal block is a gray, removable, 3-terminal plug that fits into a board-
mounted jack on the bottom right of the FX-PCV.
Wire the 24 VAC supply power wires from the transformer to the HOT and COM terminals on the
terminal plug as shown in Figure 6. The middle terminal on the supply power terminal block is not
used. See Table 5 for more information.
The supply power wire colors may be different on transformers from other manufacturers. Refer to
the transformer manufacturer’s instructions and the project installation drawings for wiring details.
Important:
Connect 24 VAC supply power to the FX-PCV and all other network devices so that
transformer phasing is uniform across the network devices. Powering network devices with
uniform 24 VAC supply power phasing reduces noise, interference, and ground loop problems.
The FX-PCV does not require an earth ground connection.
Figure 6: 24 VAC supply power terminal block wiring
7
FX-PCV Programmable Variable Air Volume Box Controllers Installation Instructions