dc fuses supplying the hazard detection and fire-
main panels. The main power CB supplying 120
volts ac to the console and the three power supply
drawer switches are also on this panel.
CALIBRATION PANEL.--Section 1A1A2
has the DCC calibration panel. This panel
contains the push buttons and potentiometers
necessary to set alarm points for low loop and low
riser pressure circuits and to set full scale on both
firemain panel pressure meters. It also has fuses
for loop and riser pressure transducer circuits.
The LP alarm points for loop and riser
circuits are set by depressing the PUSH TO
SET ALARM POINT push button and LOW
PRESSURE/METER push button at the same
time for a particular point. The LOOP AND
RISER PRESSURE meter reads the alarm set
point. By adjusting the associated ADJUST
potentiometer on the calibration panel, you
can set the alarm point to the desired value.
Releasing the two push buttons returns the
circuit to the normal condition.
Depressing the PUSH TO SET FULL SCALE
Figure 9-20.--Damage control console component location.
push button for either the loop and riser or pump
discharge meters sends a full-scale signal to the
meter. You can then make the adjustment to the
with the 155 PCBs used in monitoring, alarm, and
meter by using the mechanical full-scale adjust on
control functions. One tab of each card is used
the meter body.
to form a series circuit through all card receptacles
in all three cages and the meter circuit card.
POWER SUPPLIES.--There are nine dc
Should this circuit be disturbed (card removed),
power supplies in the DCC located in the power
the meter circuit board illuminates the CARD
supply drawers. There are two power supplies
REMOVED indicator on the firemain panel.
each for +5 volts, 5 volts, and +12 volts. Three
power supplies are used for the +24 volts. Each
RELAY PANEL.--Section 1A3A2 contains
power supply has an adjustment potentiometer
the relay panel. On the front of this panel are
for maintenance calibration. Because of the
seven lighted push buttons. Push buttons S-2
redundant power supplies, console operation is
unaffected if one supply for a particular voltage
through S-7 are used to test the automatic fire
pump control circuits for pumps 1 through 6.
level should fail. If one supply of that group
should fail, the remaining supply or supplies
A satisfactory test of a circuit is shown by
illumination of the push button after it is
automatically assume the load. Isolating diodes
depressed. Push button S-l, LAMP TEST, is
prevent the failed supply from absorbing current.
used to test the lights on this group of push
The LED for the failed supply extinguishes,
indicating that the supply has stopped supplying
buttons.
On the rear of the panel are nine relays used
voltage. At the same time, the POWER SUPPLY
FAIL light on the firemain panel illuminates. This
for automatic starting of fire pumps, summary
fire alarms, and to inhibit start-up of fire pumps
shows that one of the nine power supplies is out
during circuit tests. Associated with each relay is
of tolerance. The back panel of each power supply
a suppression diode for circuit protection.
drawer contains the LEDs and ac fuses for each
power supply and the drawer blower fuses.
FUSE AND CIRCUIT BREAKER PANEL.--
Section 1A2A2 of the DCC has the fuse and CB
OPERATION
panel. This panel contains the fuses to protect the
console's 120-volt ac fire pump and vent fan
This section is limited to general procedures
control circuits. This panel also has the 24-volt
for DCC power application, turnoff, and self-tests.
9-27
