Boiler Water Level Alarm System (CKT 1TD)

station and an indicator on the damage control

reaches the highest or lowest permissible operating

console.

level. The system consists of a drum water level

indicator for each boiler, which energizes audible and

The installation for each gas turbine module

visual alarm signals at the associated boiler operating

consists of a pressure-operated switch (manual reset)

station. Visual indications (red lights) will also be on

in the Halon actuating line in the CCS, which

energizes the following when the gas is released:

the CCS indicating board. The water level indicator

for each boiler will be provided with electrical

Alarm signals on the alarm switchboard

contacts at the high- and low-level marks on the drum.

specified for circuit F in the damage control

Either set of contacts upon closing will energize the

area of CCS

alarms.

An explosion-proof bell, IC/B2S4(EXP),

Where only one alarm is required, the system

installed within the space

consists of high- and low-water level contacts that

-- A two-dial lamp-type (red ALARM lens and

energize a type IC/H8S4 horn through a cutout switch

white POWER-ON lens) installed outside of

and a four-dial indicator (one lens blank) on the boiler

each access to the protected spaces

gauge board. The four-dial indicator will have power

A rotary snap switch in the discharge line of the

on indication and red high- and low-water level

Halon bank energizes a single-dial (red HALON RLS

indication.

lens) lamp-type indicator at the local Halon actuating

For troubleshooting the system, refer to the

station and indicators on the damage control console.

appropriate technical manual, drawings, and PMS

Supervisory resistors are provided in all pressure

cards for the system applicable to your ship.

switches used to actuate alarm modules on the circuit

F alarm switchboard, which has been previously

WRONG DIRECTION ALARM

described.

SYSTEM (CKT DW)

Individual extension alarms are provided from all

circuit FR alarm modules to the damage control

Circuit DW provides a means of warning

console.

personnel at the engine order system (EOS) area of the

When the Halon flood switch at the PCC is set, the

CCS when the operation of the propeller pitch control

circuit is closed to a solenoid valve to actuate the

mechanism is in the opposite direction to an order

Halon system within the gas turbine enclosure. A

acknowledged over the EOS. This circuit is classified

manual Halon inhibit switch at the enclosure in the

as vital readiness class 2.

open position closes the circuit to a console Halon

ready indicator.

When actual operation of the EOS does not match

Circuitry for the alarm switchboard and related

the EOS acknowledgement of the ordered propulsion

connections may be verified by switchboard test

command, the contacts in the propulsion control unit

procedures.

and the EOS close in such combination to transmit a

The remaining circuits can only be tested by

signal to the EOS WRONG DIRECTION indicator at

simulating an alarm condition at each pressure switch.

the PCC.

Power supply for each system can be verified by

When the propeller shaft watermills after a change

the white light at each access to each space.

in direction has been ordered, a reverse direction

contact in the shaft revolution transmitter closes,

Checkout procedures for the GT Halon Release

energizing a relay that, in turn, closes a contact to

System can be found in the Propulsion Control System

Technical Manual.

actuate logic circuitry, which energized the shaft

reverse rotation alarm indicator in the PCC.

BOILER WATER LEVEL ALARM

For troubleshooting and repair of the wrong

SYSTEM (CKT 1TD)

direction indicating system and the shaft reverse

rotation system, refer to the Propulsion Control

Circuit 1TD provides a means of indicating alarm

System Technical Manual.

signals for each boiler when the steam drum water

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