Wired Alarm Zone Compatibility with the Retrofit Alarm Kit

The Ring Retrofit Alarm Kit design supports a maximum resistance of 5200 ohms under supported operating conditions of temperature, battery, etc. This is intended to tolerate 4.7K, 1K or 2K end of line resistors commonly found in wired systems. Existing alarm wiring adds a small amount of resistance. (For example, 1000 feet of wire also adds about 16 ohms, which is not significant here.)

Any zones with a resistance greater than 5200 ohms are not supported because they cannot be reliably monitored by the Retrofit Alarm Kit. Adding these zones to the Retrofit Alarm Kit may drain the batteries more quickly, may damage your device, and may result in false alarms which will incur false alarm fees. 

Zone doubling is not supported with the Retrofit Alarm Kit. If your wired alarm panel uses zone doubling, any zones above 5200 ohms will not work. Use your alarm schematic to identify which zones have a lower resistance. 

Zone expanders are also not supported with the Retrofit Alarm Kit.

Note: Professional alarm installers and licensed electricians are experienced with wiring projects, are familiar with using tools such as multimeters to test electrical wiring, and can read and interpret electrical schematics. We advise you not to install this yourself if you are inexperienced in any of these areas.

The Retrofit Alarm Kit is designed for 2-wire zones. Most common are contact sensor zones.

Can I add zones that have more than two wires to my Retrofit Alarm Kit?

The Retrofit Alarm Kit is designed for two-wire zones. Four-wire zones are used for security devices that require a constant source of power. If you want to add any four-wire zones to the Retrofit Alarm Kit, you’ll need an appropriate power source, as this device is not designed to supply power to zones.

Please keep in mind that your power source will also require a reliable battery backup. If the power goes out, the zone will no longer be monitored. Without a battery backup, the zone will appear open and will trigger a false alarm every time the power goes out.

Click here to learn how to use a multimeter to test your wired zones.