The 24 VAC supply power terminal block is a gray, removable, 2-pin terminal block that fits into a board-mounted pin header on the top right of the expansion module.
Wire the 24 VAC supply power wires from the transformer to the HOT and COM terminals on the terminal plug as shown in Figure 1. For more information about the Supply Power Terminal Block, see Table 1.
Figure 1. 24 VAC supply power terminal block wiring
| Description | |
|---|---|
| 1 | Supply power terminal block |
| 2 | Supply power terminal header |
| 3 | Wires from Johnson Controls 24 VAC, class 2 power transformer |
| 4 | 24 VAC (Orange wire) |
| 5 | COM (Brown wire) |
Note: 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 expansion module 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 expansion
module does not require an earth ground connection.
Important: Power wires must be
less than 30 meters between expansion module and transformer. Inputs/outputs with cables
less than 30 m (100 ft) typically do not require an offset in the software setup. Cable
runs over 30 m (100 ft) may require an offset in the input/output software setup.