SECTION 7
CIRCUIT DESCRIPTIONS
7.1
The electronics drawer is located at the top of the detector cabinet and contains:
a.
Two redundant power supplies
b.
All system fuses
c.
Common system indicator lamps
d.
System controls
7.2
Under normal conditions it is not necessary to open the electronics cabinet. It is secured by four screws and
should not be opened by anyone except qualified maintenance personnel.
7.3
The front panel of the electronics drawer has the indicators listed in Table 7-1.
7.4
The front panel of the electronics drawer has the controls listed in Table 7-2.
7.5
The electronics drawer contains the fuses listed in Table 7-3.
7.6
The electronics drawer contains the relays listed in Table 7-4.
7.7
Figure 7-1 shows the electronics drawer fully open and the various components mentioned.
7.8
Smoke Alarm Silence Switch
The common smoke alarm will persist for approximately five minutes beyond the time that the last vestiges of
smoke are cleared from the individual line detection modules (assuming reset is operated). Common alarm is
indicated both by the illumination of the common alarm lamp and energizing of the smoke alarm bells in the.
engine room and the wheelhouse. The smoke alarm silence switch will silence the audible signals and illuminate
the smoke alarm silenced lamp located just above it.
Once the smoke alarm condition is eliminated and the panel reset, the trouble buzzer at the main cabinet and the
common signal device at the repeater cabinet will sound until the smoke alarm silence switches are restored to
normal position.
7-1
