Battery And Fuse - Bosch PRAESENSA Installation Manual

PRAESENSA
Parts check and identification
11.5.2

Battery and fuse

The multifunction power supply needs an external 12 V VRLA (Valve Regulated Lead Acid)
battery as backup power source. It uses internal DC/DC converters to convert the battery
voltage to the required supply voltages for the connected PRAESENSA devices. A 100 A fuse
(model CF8) (M) must be used in series with the positive (red) cable (N) of the battery. It is
recommended to mount the fuse at the battery side (see chapter below), immediately at the
positive battery terminal. Alternatively the fuse can be mounted at the power supply side (see
chapter below), when local standards require so. Never use two fuses, one on each side,
because this would increase the series resistance of the cable assembly and the high peak
currents of a system in emergency mode would result in voltage dips that could limit the
maximum available output power to the loudspeakers. The connected battery must have a
capacity of 100 to 230 Ah. The actual required capacity depends on many variables, see
Battery calculation, page 37 for calculation guidelines. The device is delivered with cables with
crimp eyelet terminals (N + O) and it is recommended to use these full length cables. Although
a shorter cable is better, it requires heavy tools to shorten a cable and fix new eyelet
terminals.
The temperature sensing assembly (J) is used to sense the temperature of the battery for best
performance. The temperature of the negative battery terminal is a good representation of the
internal battery temperature. Temperature sensing is an important requirement to set the
Bosch Security Systems B.V.
Multifunction power supply, large | PRA-MPS3 | en 109
A
B
C
D
E
F
I
J
K
M Battery fuse CF8 100 A
N
O
P
Q
R
S
T
U
V
W Washer M6 (x2)
Installation manual
Multifunction power supply
2‑pole screw plug (x6)
6‑pole screw plug (small, x3)
2‑pole screw plug (small, x2)
16-pole screw plug (small)
12-pole screw plug (small, x2)
Mains power cord
Temperature sensor assembly
Nut M8 (x2)
Positive battery cable (red)
Negative battery cable (black)
Bolt M8 (short, x2)
Bolt M8 (long)
Spring washer M8 (x2)
Washer M8 (x3)
Bolt M6 (short, x2)
Bolt M6 (long)
Spring washer M6 (x2)
2019.11 | V1.00 |