Can I Increase the Max Number of Zones On My Hardwired Security System?

No, you cannot increase the max number of zones on your hardwired security system. The maximum number of zones that a wired system can support is hardcoded into the firmware for the system, and it cannot be changed. Additional hardware is usually needed to make every system zone available.

Traditionally speaking, the sensors used with a wired security system are hardwired. Any sensor that is hardwired will interface with the system by running a cable from the sensor to either the panel or an added wired zone expansion module. Each set of wired terminals represents a hardwired system zone. You can have multiple wired sensors connected to a single wired zone, provided that they are of the same sensor type and use the same zone settings.

Additionally, some wired panels will support zone doubling so that you can have two (2) separate wired zones connected to the same set of zone terminals. This is done using different resistor values between the two different zones. There are typically many rules and restrictions that must be followed when using zone doubling features, and they typically vary based on the panel you are using. Make sure to keep them in mind. Also remember that not every wired panel supports zone doubling.

But an important thing to remember with wired zones is that if you don't have any open zone terminals, then you won't be able to add any additional wired zones, even if you haven't yet reached the maximum number of zones on your system. Adding one or more wired zone expansion modules to your system will provide additional zone terminals for you to add more wired zones. Keep in mind that most wired expansion modules do not support zone doubling.

Most hardwired alarm systems can be upgraded to also support wireless sensors. This is done by adding a wireless receiver to the system. Any wired system that has been upgraded in such a manner is sometimes referred to as a "hybrid" alarm system, as it will support both wired and wireless sensors. This is a great way to enhance the versatility of the system and give you more options in system planning.

When you are adding wireless sensors to a wired system with an added wireless receiver, you must choose compatible wireless sensors that communicate at the wireless frequency that is supported by the wireless receiver. For example, if the added wireless receiver supports the 345 MHz frequency, then you must use compatible 345 MHz wireless sensors, such as those from the Honeywell 5800 Series.

Also keep in mind that some wireless receiver modules have a limit to the number of wireless sensors that they can support. Some examples of wireless receiver modules with such a limitation include the Honeywell 5881ENM, which can only support up to (16) wireless zones, and the Honeywell 5881ENL, which can only support up to eight (8) wireless zones. Again, these limits remain in place even if you have not reached the total number of available system zones. Not every wireless receiver has such a limit, and some will support as many zones as the system will allow.

When you are considering the total number of zones on a wired system, you must add up both the wired zones and the wireless zones. Every system has a maximum number of total zones that cannot be exceeded. This maximum limit cannot be increased, as it is hardcoded into the firmware for the system. In the event that you reach this limit and still need to add new zones, you would need to replace the entire panel using a system with a higher total zone capacity. That is why it is important to always choose a system with sufficient zones based on your needs. It may be a good idea to get a system that supports a greater number of zones than what you think you will need, in case you ever need to expand upon the system later on.

One last thing to consider is that some zones on a wired system are usually hardcoded to be of a specific type. These are typically the on-board wired zones that are required to be set as hardwired. For example, on a Honeywell VISTA-20P, Zones 1 thru 8 represent the eight (8) on-board hardwired zones. These zones must be used as wired zones. In other words, you cannot program Zone 4 on a VISTA-20P as wireless, as it is hardcoded to be wired.

Remember, the total number of system zones is represented by the number of wired zones, plus the number of wireless zones. For the VISTA-20P, there are 64 total zones. The first eight (8) zones are represented by the on-board zone terminals. Up to (40) additional wired zones can be added using up to five (5) Honeywell 4219 or Honeywell 4229 8-Zone Expansion Modules. It is possible to have a maximum number of (56) wireless zones on the system, provided that you add an "unlimited zone" wireless receiver (e.g. Honeywell 6160RF, Honeywell 5881ENH). But for every additional wired zone you add, you lose a wireless zone. For instance, if you add a wired zone expansion module and program Zone 9 as a wired zone, or if you set up one of the compatible on-board zones for zone doubling, then that will reduce your number of available wireless zones by one (1), and you will only have 55 wireless zones available. Again, the total number of zones (wired + wireless) cannot exceed 64 on the VISTA-20P.

You can also look at this same issue from the perspective of wired zones. Since the VISTA-20P has 64 total zones, and none of them are required to be wireless, you can have up to 48 wired zones on the VISTA-20P, provided that you add enough wired zone expanders to support that many hardwired zones. But every time you add a wireless zone, you are losing the potential for a wired zone. For example, if you set Zone 20 as a wireless zone using an added wireless receiver, then you won't be able to set that zone as a hardwired zone. As such, you will then only have 47 wired zones available on the system. The final (16) zones on the VISTA-20P, Zones 49 - 64, are intended to be used for wireless key fobs, but they can actually be used for any type of wireless zone. However, these key fob zones can never be used as wired zones for hardwired sensors.