Bosch 8500 User Manual

Page of 104
EN | 66
Bosch Security Systems | December 13, 2005
18.3 AC Line Fuse Replacement
The AC line fuse on Allegiant power supply models is found on the rear of the 
equipment bay near the line cord connector. Power supply models for 220-240 VAC 
input version may contain a circuit breaker equipped power switch which can be 
reset directly from the front. If the line fuse needs to be replaced in a 120 VAC 
model power supply, remove the line cord from the system. Insert a flat blade 
screwdriver into the slot located at one end of the connector housing and rotate the 
screwdriver until the door to the housing opens. Remove fuse holder from housing 
as shown in drawing. 
Figure 14: Allegiant power supply AC line fuse
Remove fuse from holder and replace with fuse of same rating for continued protec-
tion. Reinstall fuse holder into connector housing in the same orientation as indi-
cated by the arrow on the door cover. Snap door closed. After replacing fuse, verify 
system start-up and operation.
18.4 Power Supply Fuse Replacement
The main power supply is located in the far right side of the equipment bay. 
Remove the front panel of the bay by loosening the four fasteners. Locate the fuse to 
be replaced by observing the green LED indicators. Note which LED indicators are 
not lit, then turn OFF the main power switch located on the power supply. Replace 
fuses associated with LEDs which were not lit. Switch on the main power switch and 
verify that all LEDs are now lit. Replace front panel.
18.5 Replacement of Memory Backup Batteries
CAUTION
Lithium batteries should be replaced by qualified service personnel only.
The memory backup batteries are located on the main CPU card located next to the 
power supply module in the main CPU bay. The batteries provide RAM memory 
backup for a period of at least one year. They are only active when main AC power 
to the system has been lost. The RAM memory is used to store system operational 
data which is frequently changing, including time/date and system crosspoint data 
(i.e., which camera is currently being displayed on which monitor). More vital sys-
tem data such as camera titles, alarm settings, user information and passwords, etc. is 
stored in non-volatile memory that is not affected by the condition of the batteries or 
the main AC power.
Remove the front panel of the main CPU bay by loosening the four fasteners. The 
two batteries are mounted on the front edge of the CPU card and are about 25 mm 
(1 in.) in diameter. Insert a small flat blade screwdriver into the slot on one of the 
 
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Fuse
Removal
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Fuse Removal