D7212G
Power Supply
4.2.4Battery Supervision
When the battery voltage drops to 13.8 VDC, the yellow Charging Status LED lights. When the battery drops to 12.1 VDC, the red Low Battery LED lights and the panel, if programmed for power supervision, transmits a BATTERY LOW report in the Bosch Security Systems Modem IIIa2 Communication Format. It transmits a TROUBLE ZN 9 report in the BFSK format.
If the battery is missing or shorted, the red Low Battery LED flashes at the same rate as the green Operation Monitor LED. If the panel is programmed for power supervision, it transmits a BATTERY MISSING report in the Bosch Security Systems Modem IIIa2 Communication Format, or TROUBLE ZN 9 report in the BFSK format.
When battery voltage returns to 13.7 VDC the Low Battery LED goes out. If the panel is programmed for power supervision, it transmits a BATTERY RESTORAL report in the Bosch Security Systems Modem IIIa2 Communication Format or RESTORAL ZN 9 report in the BFSK format. At 13.9 VDC the Charging Status LED goes out.
Investigate low battery reports immediately: If primary (AC) power is off and the discharge continues, the panel becomes inoperative when the battery voltage drops below 10.2 VDC.
4.2.5Battery Charging Circuit Float Charge
The float voltage for the battery charging circuit is 13.5 to 13.9 VDC at a maximum current of 1.4 A. If float voltage drops lower than 13.5 VDC, the Charging Status LED will illuminate.
Loss of AC Load Shed Relay protects battery: During an AC power loss the battery supplies all power to the security system. If the battery voltage falls below 10.2 V during an AC power loss, a “load shed” relay isolates the battery from the panel and disables the panel. Load shed protects the battery from being damaged by deep discharge. When AC power restores, the load shed relay resets and battery voltage is again available.
Overcharge Load Shed With AC Present: If more than 1.4 A of current draw from the panel is detected, the panel shuts down. Remove all loads to the panel and disconnect AC power. Add a new battery and reconnect AC power.
Reset the panel by momentarily placing the reset pin in the disable position. See Figure 4 on page 22. The red Low Battery LED continues to flash until the panel is reset.
A shorted battery condition is created either by a shorted cell inside the battery or by a short on Terminals 4 and 5. A shorted battery may generate WATCHDOG RESET reports.
4.2.6Battery Discharge/Recharge Schedule
| Discharge Cycle |
AC OFF | AC fail report when AC fails if |
| panel is programmed to report |
| AC failure at occurrence. |
13.9 VDC | Charging float level. |
|
|
13.8 VDC | Charging Status LED on. |
|
|
12.1 VDC | Low Battery & AC fail reports if |
| programmed; Low Battery LED |
| on. |
10.2 VDC | Battery load shed (processing |
| functions continue if AC is |
| present). |
|
|
| Discharge Cycle |
AC ON | Load shed relay resets, battery |
| charging begins, battery trouble |
| and AC restoral reports sent. |
13.7 VDC | Battery restoral reports sent, Low |
| Battery LED off. |
|
|
13.9 VDC | Charging Status LED off, battery |
| float charged. |
Table 7: Battery Discharge/Recharge Schedule
D7212G Operation and Installation Guide
© 2003 Bosch Security Systems | Page 27 | 4998138544C |
