ADEMCO 7845CZ Installation And Setup Manual page 26

7845CZ Installation and Setup Guide
Connect the wires from the (+) and (–) terminals of the DC power source to terminals V+ and
GND on TB1 of the 7845CZ. Observe Polarity! Refer to the "Initial Power-Up Sequence"
paragraph in this Section.
Backup Battery Connection
The included battery (ADEMCO K4362) is used for backup in the event of a system power
loss and also provides transmission current under the conditions described in the "DC Power
Connections and Options" paragraph in this section. It can provide over 4 hours of system
life in the event of a power failure. When system power is lost, the programmable DC loss
message can alert the AlarmNet Control Center (DC loss messages are reported within 10-40
minutes of actual DC loss). When the battery reaches 5.7V, a low-battery message is
transmitted, which alerts the central station that this may be the radio's last message.
When the battery reaches 5.0V, radio transmissions are no longer possible and the system
shuts down. If system power is restored before the radio shuts down, a DC Restore message
is sent and the battery is recharged using the 7845CZ's built-in battery charger. If system
power is restored after the 7845CZ has shut down, a power-on reset condition exists, and the
radio initializes itself as described earlier and the battery will recharged.
The 7845CZ performs a battery test under load on a periodic basis. During this test, if the
battery drops below 5.7V, a low-battery message is generated to indicate that the battery
should be replaced.
To install the battery, snap it into the inside of the front cover. Do not plug the battery in
until all wiring connections have been made and you are ready to power up the 7845CZ.
Refer to the "Initial Power-Up Sequence" paragraph in this Section.
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