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
CAUTION
- To avoid property damage, check all wiring connections before you apply power to the system. If you wire this terminal incorrectly, a short circuit can occur across the 24 VAC power supply on the controller. A short circuit can cause a tripped circuit breaker or a blown fuse. If you use a transformer with a built-in fuse, you may need to replace the transformer.