Can I Wire a 6150 to an AUX Power Supply?

All power outputs on Honeywell alarm panels are current limited, with the amount of current supplied varying by panel type. When connecting any device that shares data on the panel’s keypad bus to an Aux power supply, be sure to provide a common negative as shown in the diagram below.

Shown is a Vista-20P panel, a 6150, and an AD12612 power supply with 1361 transformer. Wired in this way, the 6150 will draw the current for its operation from the AD12612, rather than from terminals 4 and 5 on the Vista-20P. If you fail to provide a common negative between the power supply and the alarm panel, the 6150 will show OC or Open Circuit, as it won't be able to interpret the data being sent to it by the panel. The same would hold true for any device that sends and receives data on the keypad bus, being powered from a separate source. Other devices, such as hardwired motion detectors, would not require the common negative. Also, it should be noted that the power supply and the alarm panel can not share a transformer, nor can they share a backup battery.