Installation manual

D9124 Operation & Installation Manual

Page 30

74-06799-000-D 2/96

Battery Lead Supervision

The 12 V battery leads are supervised.

Battery Charging Circuit

Float Voltage

The float voltage for the 12 V battery charging circuit is 13.9 VDC at a maximum current

of 1.4 Amps. Deduct any continuous load for 12 V devices connected to the panel from

1.4 Amps to find the actual current available for charging.

Load Shed Relay protects battery:

During an AC power loss the battery supplies

extended power to the security system. If the battery voltage falls below 10.2 volts during

an extended AC power loss, a “load shed” relay disconnects the battery from the

D9112LTB and disables the system. Load shed protects the battery from being damaged

by deep discharge. When AC power restores, the load shed relay resets and battery is

reconnected to the D9112LTB, enabling the system.

Reset or power down required for shorted battery:

If the D9124 determines the

battery is shorted, it uses the load shed relay to disconnect the battery. You must reset or

power down the panel after correcting the problem to reset the load shed relay and

reconnect the battery.

Reset the panel by momentarily placing the reset pin in the disable position. See

Figure 7

. The red Low Battery LED continues to flash until you reset the panel.

A shorted battery condition is created either by a shorted cell inside the battery, by a

short between terminals 4 and 5, or a short between terminal 5 and earth ground. A

shorted battery may generate WATCHDOG RESET reports and corrupt the panel

program.

Power for 24 VDC Initiating and Indicating Devices (D9142)

Primary Power

The D1601 is a 120 VAC, 16.5V/24VAC dual secondary transformer that is the primary

power supply for the control/communicator and initiating devices of the D9124. See

Installing the D1601 Transformer

in the

Installation

section of this manual for more

information about installing the D1601.

Secondary Power

Secondary power for the alarm indicating devices (bells, horns, and strobes) is supplied

by two D126 12V, 7Ah, or external D1218 12V, 17.2Ah batteries, or larger, in a separate

enclosure.

Radionics recommends battery replacement every three to five years under normal use.

Use only lead acid batteries.