NATIONAL ALUMINIUM COMPANY LIMITED - Rites

linking while the faulty conveyor / equipment will be fast blinking. Start command shall not
be initiated unless reset button in pressed after clearance offault.
The sequence of operation of the annunciation system shall be as follows: follows:-
Condition
Status
Normal : Ann. Window : Off.
Status indication : Steady glow
Buzzer
: Off.
Fault : Ann. Window : Blinking.
Status indication : Fast blinking
Buzzer
: Sounding.
Press Accept PB.
Ann. Window : Steady glow.
Status indication : Fast blinking
Buzzer
: Off.
Press Reset PB (When fault is cleared):
Ann. Window : Off.
Status indication : i) Steady blinking (if on selected path)
ii) Off (if not on selected path)
Buzzer.
: Off.
4.3.7 Dust Suppression System
(a.) Conveyors / Equipment
1. It shall be possible to spray the water on to coal stream only when corresponding
conveyors/equipment’s are running with material at spray application points.
2. If a running pump trips stand stand-by pump shall start automatically. lly. It shall be possible to select
any of the pumps as auto standby from main CHP control room.
3. Pump/pumps shall trip with a time delay, if discharge valves fail to open. Suitable
pressure/flow switch shall be provided to sense this condition.
4. Pumps shall trip in case of low level of water in tank.
5. All feeding pumps to tank shall trip in case of high high-high level in tank.
6. All the controls shall be through control desk.
(b.) Wagon unloading
1. System shall be operated from local control panel.
2. Dust suppression system shall be provided to cover the WT Hopper.
3. Pumps shall be started manually or from control panel. . If any of the pump/pumps trips,
stand-by by pump/pumps shall start automatically. It shall be possible to select any of the
pumps as auto stand - by.
4. Pumps shall trip in case of low level of water in tank.
5. Following annunciation’s shall be provided at local control panel.
Technical Specification:Sec-4,System System Parameters, Operation & Control Philosophy
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