The Honeywell K0991 is an AC power adapter used to provide constant power to a 5828 or 5828V wireless alarm keypad. The K0991 is a regulated adapter with a fixed output voltage of 5VDC and a maximum power output of 220mA. Unlike an AC transformer, an AC power adapter has an attached wire to connect the power supply to the alarm device.
The Honeywell 5828 and 5828V wireless alarm keypads are battery powered devices by default. They use (3) standard AA alkaline batteries which can be replaced by accessing the battery compartment on the backside of the alarm keypad. However, to preserve battery life, Honeywell has designed the 5828 and 5828V to enter a sleep mode after (15) seconds of inactivity. While this keeps you from having to constantly replace batteries, it also can be an inconvenience. Unfortunately, once the alarm keypads enter sleep mode, the only way to wake them back up is by pressing the [*] key. The keypads will not wake up when you enter the programmed delay zone and if you forget that your security system is armed, you may be startled by a false alarm. We have heard that some customers, especially those with lots of users, find this a design defect of the Honeywell wireless alarm keypads.
Fortunately, even if it is a defect, it can be easily fixed by using a Honeywell K0991 AC power adapter. Simply plug the power adapter’s DC plug into the input connector on the backside of the 5828 or 5828V keypad and then plug the K0991 into a standard unswitched wall outlet. The alarm keypad will stay active and will not enter sleep mode as long as the K0991 is plugged in. Anyone that is purchasing, or already has purchased, a 5828 or 5828V should seriously consider adding the optional AC power adapter.
Even when using the Honeywell K0991 AC power adapter, you should still keep the (3) AA batteries installed in your wireless alarm keypad. If you do, the alarm keypads can still operate during a power outage. You will need to press the [*] key to wake up the keypad because it will have gone to sleep after the power outage, but at least you still have a means of operating the keypad without having to fumble in the dark for batteries. Please note that after the power is restored, you must hit the [*] key to switch the keypad back to AC power mode.
Every 5828DM desk mount kit includes a K0991 AC power adapter so consider the 5828DM if you want to keep your keypad powered at all times and be able to use it from a desk or counter top. Also, your 5828 or 5828V alarm keypad may still take up to (5) seconds to display your alarm control panel’s system status even when using the K0991.