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On detection of fire, the fire system initiates the HOOD fan shutdown. This is to minimize the PRESENCE of AIR the hood for releasing the EXTINGUISHER.

On detection of fire, the fire system initiates the hood fan shutdown. This is to minimize the presence of air the hood for releasing the extinguisher.

A TIME DELAY of 15 secs. Is set between the detection of fire and the initiation of HALON release. This is to achieve effective fire extinguishing by allowing the hood fan to run-down to zero speed and the BLEED valves to release the compressed air.

A time delay of 15 secs. Is set between the detection of fire and the initiation of Halon release. This is to achieve effective fire extinguishing by allowing the hood fan to run-down to zero speed and the bleed valves to release the compressed air.

On ACTIVATING, the ventilation defeat switch inhibits the release of HALON in the auto MODE and ALSO the unit shutdown on ‘ventilation failure’.

On activating, the ventilation defeat switch inhibits the release of Halon in the auto mode and also the unit shutdown on ‘ventilation failure’.

Prior to ENTERING a gas TURBINE, turn on the ‘ventilation defeat SWITCH’.

Prior to entering a gas turbine, turn on the ‘ventilation defeat switch’.

Generally on the GAS MONITOR, the alarm is SET at 20%rising and the SHUTDOWN is set at 60%rising (refer to the STATION drawing for the exact settings parameters)

Generally on the gas monitor, the alarm is set at 20%rising and the shutdown is set at 60%rising (refer to the station drawing for the exact settings parameters)

1. Gas sensor loop current or voltage at the sensor HEAD is set as PER the manufacturer’s recommended value.
2. Gas MONITOR zero is adjusted to the instrument air.
3. A test gas with a known quantity of combustion gas (Generally methane 2% by volume) is fed to the sensor and the span is adjusted to read 40% on the monitor scale (refer to the station drawings for the exact settings parameters).
4. The calibration procedure is repeated until the zero and span READS correctly.

GAS MONITOR MEASURES the imbalance in the current loop CAUSED by its ACTIVE and inactive filaments in the presence of a combustible gas.

Gas monitor measures the imbalance in the current loop caused by its active and inactive filaments in the presence of a combustible gas.

On detection of HEAT, the heat SWITCH initiates the following:

Annunciation, audible alarm on the control panel, a siren in the field, shut down of the TURBINE and RELEASE of FIRE extinguisher (refer to the station drawings for the exact settings parameters).

On detection of heat, the heat switch initiates the following:

Annunciation, audible alarm on the control panel, a siren in the field, shut down of the turbine and release of fire extinguisher (refer to the station drawings for the exact settings parameters).

The reason COULD be:

• HOOD VENTILATION fan has failed or STOPPED.
• Major HOT gas leak inside the hood.

The reason could be:

Heat SWITCHES are a mechanical TYPE and they are CONSIDERED to be a positive type of fire detection system. The heat switch settings are much higher than the HOOD temperature.

Heat switches are a mechanical type and they are considered to be a positive type of fire detection system. The heat switch settings are much higher than the hood temperature.

Auto Halon cylinder can be DISCHARGED manually from the fire & gas control panel in the control ROOM. On instiating the manual release:

• The unit shuts down.
• The auto Halon cylinder gets discharged in the HOOD.
• Auto halon discharge confirmation and the auto Halon cylinder pressure low alarm appears on the control panel.
• Audible alarm in the control room and siren in the field occurs.

Manual Halon cylinder can discharge manually from the field through a pall string. On INITIATING the manual release:

• The unit SHUTDOWN.
• The manual Halon cylinder gets discharged in the hood.
• Manual Halon discharge confirmation and the manual Halon cylinder pressure low alarm appears on the control panel.
• Audible alarm in the control room and siren in the field occurs.

Auto Halon cylinder can be discharged manually from the fire & gas control panel in the control room. On instiating the manual release:

Manual Halon cylinder can discharge manually from the field through a pall string. On initiating the manual release:

Generally it is SET for 4 secs. The UV DETECTORS INITIATES a fire alarm only when the UV is detecting the fire continuously for 4 secs (refer to the station drawings for the exact SETTINGS parameters).

Generally it is set for 4 secs. The UV detectors initiates a fire alarm only when the UV is detecting the fire continuously for 4 secs (refer to the station drawings for the exact settings parameters).

1 out of 4 UVs: creates ANNUNCIATION, audible alarm on the CONTROL panel and siren in the field (refer to the STATION drawings for the exact function and operations).

2 out of 4 UVs: creates annunciation, audible alarm on the control panel, a siren in the field, shutdown of the turbine and release of the FIRE extinguisher (refer to the station drawings for the exact function and operations).

1 out of 4 UVs: creates annunciation, audible alarm on the control panel and siren in the field (refer to the station drawings for the exact function and operations).

2 out of 4 UVs: creates annunciation, audible alarm on the control panel, a siren in the field, shutdown of the turbine and release of the fire extinguisher (refer to the station drawings for the exact function and operations).

There are TWO voting logics, they are: 1 out of 4 UV s and 2 out of 4 UVs.

There are two voting logics, they are: 1 out of 4 UV s and 2 out of 4 UVs.

• Solar GAS TURBINE hood: 4 UV DETECTORS
• RUSTON TA1750 hood: 4 UV detectors
• Ruston TB5000 hood: 12 UV detectors

The first bottle is the ‘first shot’ and the second bottle is ‘Extended shot’. The first bottle discharges the GALLON into the HOOD through a 1’’ pipe in APPROXIMATELY 15 seconds, where as the extended bottle discharges the HALON through a ¼’’ pipe for another ½’’HOUR period to maintain the inert atmosphere.

The first bottle is the ‘first shot’ and the second bottle is ‘Extended shot’. The first bottle discharges the Gallon into the hood through a 1’’ pipe in approximately 15 seconds, where as the extended bottle discharges the Halon through a ¼’’ pipe for another ½’’hour period to maintain the inert atmosphere.

The EXPANSION FORM of B.F.C is BROMO CHLORO FLORIDE.

The expansion form of B.F.C is Bromo chloro floride.

HALON is stored in liquid form in a cylinder. When it is RELEASED in a HOOD during the occurrence of the fire, it discharges the halon in gas from. Halon does not act or REACT on electrical components.

Halon is stored in liquid form in a cylinder. When it is released in a hood during the occurrence of the fire, it discharges the halon in gas from. Halon does not act or react on electrical components.

During a gas turbine normal RUNNING CONDITION, a hood provides:

• Prevention of turbine high dB noise to outside areas.
• Keeps the gas turbine clean from EXTERNAL dust.
• Provides a DRAFT for the gas leak to the exhaust through the hood fan.

During a gas turbine shutdown condition a hood provides:

• Cooling the turbine body by way of the hood fan.
• During a FIRE shutdown it facilitates to put out the fire by confining the fire extinguishers on the gas turbine.

During a gas turbine normal running condition, a hood provides:

During a gas turbine shutdown condition a hood provides:

A fire triangle represents the three ELEMENTS, which causes a fire in a COMBUSTIBLE mixture. The three elements are fuel, AIR and ignition.

A fire triangle represents the three elements, which causes a fire in a combustible mixture. The three elements are fuel, air and ignition.