Connect the 24 VAC supply power wires from the transformer to the HOT and COM power terminals as shown in Figure 1.
Note: The supply power wire colors may differ on transformers from other manufacturers. Refer to the transformer manufacturer’s instructions and the project installation drawings for wiring details.
Important: To reduce noise, interference, and ground loop problems, connect a 24 VAC supply power to the controller and to all other network devices so that transformer phasing is uniform across network devices. The controller does not require an earth ground connection. However, when you need to ground the secondary of the 24 VAC transformer, make only one ground connection near the transformer. For more information, see the following figure.
Figure 1. Transformer grounding