Under normal operating conditions, the sensor
has failed. This circuit is classified as semivital
readiness class 1.
detects the airflow by rotation of its vanes. An
interruption of contacts as the vanes turn produces the
One 400-Hz and one 60-Hz relay is provided as
pulses that operate the meter.
integral units of the main IC switchboard. Two
modules on the IC/SM alarm switchboard in the
The indicator is an electronic signal unit type
machinery control area of CCS function in this alarm
IC/E102, a modification of the IC/EIDI. It serves as
the alarm portion of the system and can be used with
remote alarm units. A 12-volt battery inside the
Each of the relays on the main IC switchboard is
enclosure supplies power to the entire unit during
normally held energized by the bus voltage. Failure of
normal and emergency operations.
the bus voltage permits the relay to assume the normal
(de-energized) position, shorting the supervisory
resistor by closing the alarm contacts to the associated
module in the type IC/SM alarm switchboard in the
machinery control area of CCS. Operation of the bus
Preventive maintenance of the systems should be
failure alarm signal at the main IC switchboard is also
done according to the MRCs associated with each
controlled by two bus relays and is described in the
system. Preventive maintenance consists of routine
technical manual for the switchboards.
cleaning, visual inspection of components, and testing.
Corrective maintenance of the systems is relatively
SECURITY ALARM SYSTEM (CKT FZ)
easy to perform. Almost any trouble that will affect
system operation gives an audible and/or visual
The purpose and use of the security alarm system
is confidential. During normal ship operations, testing
and maintenance of the system and its monitored areas
If an open occurs in one of the systems, an alarm
should follow the two-man rule; that is, a minimum of
condition cannot be detected. Therefore, the problem
two authorized personnel capable of detecting
should be found and corrected as soon as possible, In
incorrect or unauthorized procedures with respect to
some cases, such as open supervisory relay contacts, no
the task to be performed and familiar with applicable
indication will be received to indicate a trouble
safety and security procedures must be present. All
keys to the switchboard door locks, terminal box
Shorted switch contacts or relay contacts in one of
padlocks, and so on, are to be handled as SECRET
the systems could result in false alarm conditions or
material, and should remain in the possession of
blown fuses. A short in an audible or visual signal will
designated ship's security personnel. If either a lock
affect the operation of the system only during an alarm
or its key is lost, both must be replaced immediately.
condition. The short will cause an increase in current
Refer to NAVSHIPS 401-4538943, Security
flow and will result in blown fuses.
Alarm System Circuit FZ Elementary and Isometric
Wiring Diagram (CONFIDENTIAL), for equipment
A ground in one of the systems could also result in
description, operation, and location. Because of the
false alarms or blown fuses. Grounds can be either
confidentiality involved, you will have to refer to the
single or multiple on the same side of the line or
NAVSHIPS 401-4538943 and applicable PMS cards
simultaneous on both sides of the line.
for procedures to troubleshoot and repair the system,
Mechanical problems, such as a weak spring on art
alarm relay, will also result in a false alarm.
AIR FLOW INDICATOR AND ALARM
PANEL (TYPE IC/APE)
If a complete loss of power occurs in an alarm panel,
check the fuses that supply primary power to the panel.
If the fuses are good, open the panel and check the
The airflow indicator and alarm panel (circuit HO)
incoming line connections with a voltmeter. If power is
is a remote panel installed in each compartment that
not present, the problem is in the cable that supplies
needs a constant supply of fresh air, The meter can
power to the panel. If power is present, check the power
indicate a flow of air not exceeding 1000 feet per minute
transformer and rectifier. For more information on
(fpm). An alarm sounds when the airflow from the
troubleshooting alarm panels, refer to the applicable
exhaust ventilation decreases to a predetermined level,
which is set by a second pointer on the meter face.
manufacturer's technical manual.