The 24 VAC supply power terminal block is a gray, removable, 2-terminal plug that fits into a board-mounted jack on the upper left of the ZEC controller. Wire the 24 VAC supply power wires from the transformer to the HOT and COM terminals on the terminal plug as shown in the following figure.
Figure 1. Supply power terminal block wiring

1 | Supply power terminal block jack |
2 | Supply power terminal block plug |
3 | Wires from Johnson Controls 90 VAC to 24 VAC, Class 2, power transformer |
Important: Do not share the 24 VAC power with other network devices. Sharing
power with other network devices can cause noise, interference, and ground loop
problems. You may damage the controller by sharing power with other devices.