Connect the 24 VAC supply power wires from the transformer to the HOT and COM power terminals as shown in figure 15.
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 power supply 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 figure 15.
Figure 1. Transformer grounding
CAUTION
- Risk of Property Damage
- Before you apply power to the system, check all wiring connections. 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.