BBB Business Review

How do I wire DSC keypads?


Wiring the keypads to the control panels is relatively straightforward. All keypads will connect in parallel with the four keybus terminals: RED, BLK, YEL, GRN. These terminals are named after the standard colors of 22 gauge 4 conductor alarm wire. And each keypad will also have similarly named terminals to match. You will wire these terminals together red to red, black to black, yellow to yellow, and green to green. For a basic system setup that is pretty much all you will need to know. There are a few other details and tips that can be very useful to know though. 

First, is how multiple keypads can be wired. This also applies to other modules on the keybus. The first option is to do a home run to the main PowerSeries control panel from the keypad for each keypad. Sometimes this is the most efficient way to do things depending on your layout. Another option would be to wire keypads in parallel. So going from the main circuit board you would connect to the first keypad. And then from that first keypad you could connect to the second keypad. And so on until everything is wired to the keybus. You can also do combinations of this or variations. So you could have 2 keypads wired in parallel from the panel. Then 1 keypad could have its own home run to the main panel. Or you could have 1 keypad wired to the main panel. Then 2 keypads that each wire directly to that first keypad. 

One thing that you cannot do is split off from the middle of a wire to another device. And forks that happen need to happen at the main panel, keypads, or other modules. 

The next thing that you may need to keep in mind as well will generally only affect larger installations. There are wire length limits that affect the keybus. There is two components to the wire length limits. First, a single keypad/module cannot have more than 1000 feet of wire between it and the control panel. This could be a home run directly for that device or it could have multiple components in parallel. The second rule is that the keybus cannot have more than 3000 feet of total wire length between all wire runs. So depending on how you have things setup you may run into issues with one rule and not the other and you may need to rework how things are wired to stay within these parameters. But again, the vast majority of installations will never need to worry about this as the limits are almost always well beyond what you will need.

Now that you know how to run the wires and where they need to connect you may run into another problem that begs the question: how do I fit all these wires under this 1 terminal? We have run into this same problem numerous times and do not worry, we have a solution. We have generally found that 3 wires fit comfortably under a single terminal and more is possible, but it gets more and more messy with more and more room for error. So we have found that using a couple bus terminal expander on the keybus makes things so much easier. Each one has two sides and each side takes 1 terminal and expands it into 6 terminals. For a decent sized system they are well worth investing in.

Keypads that this information refers to are as follows: