BRINKS BHS-4000A - 3.13 Calculating System Loading; 3.14 Output Current Limits

BHS-4000A Installation and Programming Instructions
Operational States under no AC/ Battery condition
> 12 VDC - Normal Operation
<11.9 VDC - Normal Operation - Low Battery Condition
<9.9 VDC - Load Shed Condition
Two batteries can be connected in parallel to achieve a higher Ah
rating. The BHS-3902 battery harness uses a self-resetting circuit
to protect against short circuit and battery reversal.
Batteries
Using the BHS-3902 Battery Harness
When using the BHS-3902 battery harness:
• Connect the lead to the panel battery leads, and observe
the proper polarity when connecting the batteries.
• Both batteries must have the same Ah rating, and should
have the same lot number or date code.
• Batteries should be replaced every 3-5 years
• Use a 40VA transformer when using batteries having a
capacity over 7.5Ah.
3.13 Calculating System Loading
The tables below will help you calculate system loading and the
size of backup battery required for your installation.
The first table lists the requirements for the BHS-4000A control
panel and each system accessory. Use this table to determine the
Standby Current (Is) requirements for UL installations.
Product
Max Current
Qty
Total
BHS-4000A Control Panel 110mA 1
110 mA
BHS-3101 Icon Keypad or
BHS-3102 Irda Keypad
55 mA
80 mA
BHS-3111 LED Keypad or
BHS-3112 Irda Keypad
55 mA
80 mA
S3201 Zone Expander Module
60 mA
S3210 Keyfob Receiver 55 mA
DT-720 Motion Sensor
25 mA
FG-1515 Glassbreak Detector
15 mA
240-COe Carbon Monoxide
Detector
8 mA
BHS-3250 Receiver
135 mA
BHS-3230 Commercial ZEM
45 mA
BHS-3420 Barran Reporting
Module
650 mA
Aux output on BHS-3250
2350-SUP Bell Sup. Module
15 mA
(Sensors) Auxiliary Power + Aux
out on BHS-3250
Fire Power (2mA per2112ATL)
Active Zones (normally closed)
Active Zones (EOL)
Total Is
The second table will aid you in determining the backup
requirements of the system during an alarm condition. Use this
table to determine the total Alarm current (la).
Product Alarm
Total
Control Panel and Accessories
From above
2112ATL Smoke Detector
30 mA
240-COe Carbon Monoxide
Detector
75 mA
ibh
Bell
*
■ 1
4 Ohm Siren Load
260 mA
8—12 Ohm Siren Load
170 mA
Total for la
*The current requirements for a bell vary. Refer to the
documentation that comes with the sensor for the actual current
requirements.
The battery’s Ah rating must be reduced (derated) based upon
the amount of standby time required. The derating value (D) is
1.05 for 24-hour backup and 1.25 for 4-hour backup.
To determine the total Ah rating of your battery, use the following
formula:
Ah = ((Is * Standby Hours) + (la * Alarm hours)) * D
Note: Is and la should be in Amps (Example: 170mA = 0.17A)
The Alarm hours are calculated as follows: Alarm Hours = Alarm
Minutes/60. For example, 4-5 minutes = 0.083 hours; 10
minutes = 0.167 hours; and 15 minutes = 0.25 hours.
3.14 Output Current Limits
The following table shows the Voltage Range and Current Limits
for each Output terminal of the BHS-4000A.
Function
Terminal
Voltage
Range
Current
Limit
Combined
Current
Comments
Bell/Strobe
Bell
9-14 1 A
1.2 A**
Speaker
Siren
N/A
N/A 4 -12 Ohm
Keypad and
Accessories
Aux
9-14
1 A
4-wire Smoke
Fire 9-14
1 A
** The total combined current shown is for the 40 VA transformer.
If using a 25 VA transformer, the total should be reduced to 1.0 A.
The maximum current draw needs to include the control panel
current.