DOC AIRBUS | AMM A320FCARGO COMPARTMENT HEATING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. Cargo-Compartment Heating
Hot bleed-air, from the hot-air manifold, is mixed with cabin-air and delivered to the FWD cargo-compartment ventilation-system (Ref. AMM D/O 21-28-00-00). This raises the temperature in the compartment to a preselected level.
Hot bleed-air, from the APU bleed-air duct, is mixed with cabin-air and delivered to the AFT cargo-compartment ventilation-system (Ref. AMM D/O 21-28-00-00). This raises the temperature in the compartment to a preselected level.
Hot bleed-air, from the hot-air manifold, is mixed with cabin-air and delivered to the FWD cargo-compartment ventilation-system (Ref. AMM D/O 21-28-00-00). This raises the temperature in the compartment to a preselected level.
Hot bleed-air, from the APU bleed-air duct, is mixed with cabin-air and delivered to the AFT cargo-compartment ventilation-system (Ref. AMM D/O 21-28-00-00). This raises the temperature in the compartment to a preselected level.
2. Component Location
AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL
AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL
AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL
FWD Cargo Compartment - Component Location ** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL AFT Cargo Compartment - Component Location ** ON A/C NOT FOR ALL FWD Cargo Compartment - Component Location ** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 1HC | FWD CARGO HEAT CONTROLLER | 95VU | 121 | 21-43-34 | |
| 2HC | FWD CARGO TRIM AIR VALVE | 132PW | 137 | 21-43-53 | |
| 3HC | FWD CARGO DUCT SENSOR | 131HW | 131 | 21-43-14 | |
| 4HC | FWD CARGO COMP SENSOR | 132KW | 132 | 21-43-14 | |
| 5HC | FWD CARGO TEMP SELECTOR | 22VU | 210 | 21-43-16 | |
| ** ON A/C NOT FOR ALL | |||||
| 10HC | AFT CARGO HEAT CONTROLLER | 96VU | 121 | 21-43-34 | |
| 11HC | AFT CARGO PRESS REG VALVE | 197 | 21-43-52 | ||
| 12HC | AFT CARGO TRIM AIR VALVE | 197BB | 197 | 21-43-51 | |
| 13HC | AFT CARGO DUCT SENSOR | 151EW | 151 | 21-43-15 | |
| 14HC | AFT CARGO COMP SENSOR | 152 | 21-43-15 | ||
| 15HC | AFT CARGO TEMP SELECTOR | 22VU | 210 | 21-43-17 | |
3. System Description
AFT Cargo Compartment - General Schematic ** ON A/C NOT FOR ALL
Aft Cargo Compartment - General Schematic ** ON A/C NOT FOR ALL
Hot bleed-air from the hot-air manifold goes through the trim-air valve 2HC. It then mixes with air from the cabin and goes into the FWD cargo compartment. This air enters the supply duct upstream of the inlet isolation-valve 5HN.
A proximity switch, installed at the FWD cargo-compartment door, inhibits the FWD cargo-compartment heating system if the cargo-compartment door is open. This door must be closed to enable the heating system to function.
The temperature control system regulates the amount of hot air added, to give the preselected temperature in the cargo compartment. The heating controller 1HC, which gets information from the temperature sensors 3HC and 4HC, controls the system. These sensors are installed in the inlet duct (3HC) and in the extraction duct (4HC). The temperature of the air, which enters the supply duct, is controlled to a maximum of 70 DEG.C (158.00 DEG.F) by the trim-air valve 2HC.
When the duct temperature goes above 88 DEG.C (190.40 DEG.F), the FAULT light on the HOT AIR switch 7HK comes on and the trim-air pressure-regulating valve 14HK closes. This overheat condition will be latched by the heating controller. When the duct temperature decreases to 70 DEG.C (158.00 DEG.F) the heating system can be reset. To do this you must push the HOT AIR switch 7HK OFF and then ON again.
Hot bleed-air from the APU bleed-air duct goes through the pressure regulating valve 11HC and the trim-air valve 12HC. It then mixes with air from the cabin before going to the AFT cargo compartment. This air enters the supply duct upstream of the inlet isolation-valve 34HN.
Proximity switches are installed at the AFT cargo-compartment door and at the bulk cargo-compartment door. These switches will inhibit the AFT cargo-compartment heating system if one of the doors is open. Both doors must be closed to enable the heating system to function.
The temperature control system regulates the amount of hot air added, to give the preselected temperature in the AFT cargo compartment. The heating controller 10HC, which gets information from the temperature sensors 13HC and 14HC, controls the system. These sensors are installed in the inlet duct (13HC) and at the extraction duct of the Cargo Compartment (14HC). The temperature of the air, which enters the supply duct, is controlled to a maximum of 70 DEG.C (158.00 DEG.F) by the trim-air valve 12HC.
When the duct temperature goes above 88 DEG.C (190.40 DEG.F), the FAULT light on the HOT AIR switch 16HC comes on and the pressure regulating-valve 11HC closes. This overheat condition is latched by the heating controller. When the duct temperature decreases to 70 DEG.C (158.00 DEG.F) the system can be reset. To do this you must push the HOT AIR switch 16HC OFF and then ON again.
** ON A/C NOT FOR ALL AFT Cargo Compartment - General Schematic ** ON A/C NOT FOR ALL Aft Cargo Compartment - General Schematic ** ON A/C NOT FOR ALL A proximity switch, installed at the FWD cargo-compartment door, inhibits the FWD cargo-compartment heating system if the cargo-compartment door is open. This door must be closed to enable the heating system to function.
The temperature control system regulates the amount of hot air added, to give the preselected temperature in the cargo compartment. The heating controller 1HC, which gets information from the temperature sensors 3HC and 4HC, controls the system. These sensors are installed in the inlet duct (3HC) and in the extraction duct (4HC). The temperature of the air, which enters the supply duct, is controlled to a maximum of 70 DEG.C (158.00 DEG.F) by the trim-air valve 2HC.
When the duct temperature goes above 88 DEG.C (190.40 DEG.F), the FAULT light on the HOT AIR switch 7HK comes on and the trim-air pressure-regulating valve 14HK closes. This overheat condition will be latched by the heating controller. When the duct temperature decreases to 70 DEG.C (158.00 DEG.F) the heating system can be reset. To do this you must push the HOT AIR switch 7HK OFF and then ON again.
Hot bleed-air from the APU bleed-air duct goes through the pressure regulating valve 11HC and the trim-air valve 12HC. It then mixes with air from the cabin before going to the AFT cargo compartment. This air enters the supply duct upstream of the inlet isolation-valve 34HN.
Proximity switches are installed at the AFT cargo-compartment door and at the bulk cargo-compartment door. These switches will inhibit the AFT cargo-compartment heating system if one of the doors is open. Both doors must be closed to enable the heating system to function.
The temperature control system regulates the amount of hot air added, to give the preselected temperature in the AFT cargo compartment. The heating controller 10HC, which gets information from the temperature sensors 13HC and 14HC, controls the system. These sensors are installed in the inlet duct (13HC) and at the extraction duct of the Cargo Compartment (14HC). The temperature of the air, which enters the supply duct, is controlled to a maximum of 70 DEG.C (158.00 DEG.F) by the trim-air valve 12HC.
When the duct temperature goes above 88 DEG.C (190.40 DEG.F), the FAULT light on the HOT AIR switch 16HC comes on and the pressure regulating-valve 11HC closes. This overheat condition is latched by the heating controller. When the duct temperature decreases to 70 DEG.C (158.00 DEG.F) the system can be reset. To do this you must push the HOT AIR switch 16HC OFF and then ON again.
4. Power Supply
AFT Cargo Compartment Heating - Electrical Schematic ** ON A/C NOT FOR ALL
AFT Cargo Compartment Heating - Electrical Schematic ** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL AFT Cargo Compartment Heating - Electrical Schematic ** ON A/C NOT FOR ALL AFT Cargo Compartment Heating - Electrical Schematic ** ON A/C NOT FOR ALL 5. Component Description
A. Temperature Sensors FIN: 3-HC FIN: 4-HC
The FWD cargo-compartment duct temperature-sensor 3HC is installed in the inlet duct. The FWD cargo-compartment duct temperature-sensor 4HC is installed in the extraction duct. Each sensor consists of a stainless-steel housing that contains of a thermistor and is surrounded with a ventilated shield. An electrical connector is installed to connect the thermistor to the wiring of the controller 1HC.
The AFT cargo-compartment duct temperature-sensor 13HC is installed in the inlet duct. The AFT cargo-compartment temperature-sensor 14HC is installed at the extraction duct. Each sensor consists of a stainless-steel housing that contains a thermistor and is surrounded with a ventilated shield. An electrical connector is installed to connect the thermistor to the wiring of controller 10HC.
The FWD cargo-compartment duct temperature-sensor 3HC is installed in the inlet duct. The FWD cargo-compartment duct temperature-sensor 4HC is installed in the extraction duct. Each sensor consists of a stainless-steel housing that contains of a thermistor and is surrounded with a ventilated shield. An electrical connector is installed to connect the thermistor to the wiring of the controller 1HC.
The AFT cargo-compartment duct temperature-sensor 13HC is installed in the inlet duct. The AFT cargo-compartment temperature-sensor 14HC is installed at the extraction duct. Each sensor consists of a stainless-steel housing that contains a thermistor and is surrounded with a ventilated shield. An electrical connector is installed to connect the thermistor to the wiring of controller 10HC.
B. Temperature Selector
The temperature selector 5HC for the FWD cargo compartment is installed on the CARGO HEAT panel 22VU in the cockpit. The selector consists of a rotary potentiometer which is contained inside a metal housing. An electrical connector, attached to the base of the housing, connects the potentiometer to the electrical wiring of the heating controller.
The temperature range that the selector can set is between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F), with 15.5 DEG.C (59.90 DEG.F) at the 12 o'clock position. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
The temperature selector is electrically connected to the heating controller 1HC for temperature control functions.
The temperature selector 15HC for the AFT cargo compartment is installed on the CARGO HEAT panel 22VU in the cockpit. The selector consists of a rotary potentiometer which is contained inside a metal housing. An electrical connector, attached to the base of the housing, connects the potentiometer to the electrical wiring of the heating controller.
The temperature range that the selector can set is between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) with 15.5 DEG.C (59.90 DEG.F) at the 12 o'clock position. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
The temperature selector is electrically connected to the controller 10HC for temperature control functions.
The temperature selector 5HC for the FWD cargo compartment is installed on the CARGO HEAT panel 22VU in the cockpit. The selector consists of a rotary potentiometer which is contained inside a metal housing. An electrical connector, attached to the base of the housing, connects the potentiometer to the electrical wiring of the heating controller.
The temperature range that the selector can set is between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F), with 15.5 DEG.C (59.90 DEG.F) at the 12 o'clock position. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
The temperature selector is electrically connected to the heating controller 1HC for temperature control functions.
The temperature selector 15HC for the AFT cargo compartment is installed on the CARGO HEAT panel 22VU in the cockpit. The selector consists of a rotary potentiometer which is contained inside a metal housing. An electrical connector, attached to the base of the housing, connects the potentiometer to the electrical wiring of the heating controller.
The temperature range that the selector can set is between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) with 15.5 DEG.C (59.90 DEG.F) at the 12 o'clock position. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
The temperature selector is electrically connected to the controller 10HC for temperature control functions.
C. Trim-Air Valve
A hot-trim-air valve 2HC is installed in the trim air supply duct to the FWD cargo compartment. The valve is made from a light alloy and is of the butterfly type. A stepper motor drives a center shaft (to which the butterfly valve is attached) through reduction gears. The valve also has mechanical stops and limit switches. The limit switches stop the valve opening or closing more than their preset position and the mechanical stops are a backup. A manual override and a visual position-indicator are installed on the end of the shaft. The step counter of the controller 1HC counts the steps of the stepper motor to calculate the position of the valve butterfly for indication on ECAM. A return spring closes the trim-air valve 2HC, if the power supply or the controller 1HC do not operate.
A hot trim-air valve 12HC is installed in the trim air supply duct to the AFT cargo compartment. This valve is made from light alloy and is of the butterfly type. A stepper-motor drives a center shaft (to which the butterfly valve is attached) through reduction gears. The valve also has mechanical stops and limit switches. The limit switches stop the valve opening or closing more than their preset position and the mechanical stops are a backup. A manual override and a visual position-indicator are installed on the end of the shaft. The step counter of the controller 10HC counts the steps of the stepper motor to calculate the position of the valve butterfly for indication on ECAM. A return spring closes the trim-air valve 12HC if the power supply or the controller 10HC do not operate.
A hot-trim-air valve 2HC is installed in the trim air supply duct to the FWD cargo compartment. The valve is made from a light alloy and is of the butterfly type. A stepper motor drives a center shaft (to which the butterfly valve is attached) through reduction gears. The valve also has mechanical stops and limit switches. The limit switches stop the valve opening or closing more than their preset position and the mechanical stops are a backup. A manual override and a visual position-indicator are installed on the end of the shaft. The step counter of the controller 1HC counts the steps of the stepper motor to calculate the position of the valve butterfly for indication on ECAM. A return spring closes the trim-air valve 2HC, if the power supply or the controller 1HC do not operate.
A hot trim-air valve 12HC is installed in the trim air supply duct to the AFT cargo compartment. This valve is made from light alloy and is of the butterfly type. A stepper-motor drives a center shaft (to which the butterfly valve is attached) through reduction gears. The valve also has mechanical stops and limit switches. The limit switches stop the valve opening or closing more than their preset position and the mechanical stops are a backup. A manual override and a visual position-indicator are installed on the end of the shaft. The step counter of the controller 10HC counts the steps of the stepper motor to calculate the position of the valve butterfly for indication on ECAM. A return spring closes the trim-air valve 12HC if the power supply or the controller 10HC do not operate.
D. Heating Controller
The FWD cargo-compartment heating-system has its own controller 1HC. The controller is a 1 MCU box which is installed in the avionics compartment, in rack 95VU . The function of the controller is to regulate the temperature in the FWD cargo compartment to preselected values. The required temperature is selected with the temperature selector 5HC, which is installed on the cockpit overhead panel 22VU. The controller also sends signals to the CFDS and ECAM via the ARINC 429 data bus. The controller's circuits are fully digital and include BITE. If the variable control function of the controller does not operate, the trim-air valve 2HC will close. This is done independently of the controller.
The AFT cargo-compartment heating-system has its own controller 10HC. The controller is a 1 MCU box which is installed in the avionics compartment, in rack 96VU. The function of the controller is to regulate the temperature in the AFT cargo compartment to preselected values. The required temperature is selected with the temperature selector 15HC, which is installed on the cockpit overhead panel 22VU. The controller also sends signals to the CFDS and ECAM via the ARINC 429 data bus. The controller's circuits are fully digital and include BITE. If the variable control function of the controller does not operate, the trim-air valve 12HC and the pressure regulating valve 11HC will close. This is done independently of the controller.
The FWD cargo-compartment heating-system has its own controller 1HC. The controller is a 1 MCU box which is installed in the avionics compartment, in rack 95VU . The function of the controller is to regulate the temperature in the FWD cargo compartment to preselected values. The required temperature is selected with the temperature selector 5HC, which is installed on the cockpit overhead panel 22VU. The controller also sends signals to the CFDS and ECAM via the ARINC 429 data bus. The controller's circuits are fully digital and include BITE. If the variable control function of the controller does not operate, the trim-air valve 2HC will close. This is done independently of the controller.
The AFT cargo-compartment heating-system has its own controller 10HC. The controller is a 1 MCU box which is installed in the avionics compartment, in rack 96VU. The function of the controller is to regulate the temperature in the AFT cargo compartment to preselected values. The required temperature is selected with the temperature selector 15HC, which is installed on the cockpit overhead panel 22VU. The controller also sends signals to the CFDS and ECAM via the ARINC 429 data bus. The controller's circuits are fully digital and include BITE. If the variable control function of the controller does not operate, the trim-air valve 12HC and the pressure regulating valve 11HC will close. This is done independently of the controller.
E. Pressure Regulating-Valve
The pressure regulating-valve 14HK regulates the pressure of the air supplied to the trim-air valve 2HC. It performs the system shut-off function. The valve is a three-inch steel-butterflv type which is pneumatically actuated, and electrically signalled. The function of the valve is to act as an on/off valve for the trim-air system. It also regulates the downstream pressure to a nominal 280 mbar above cabin pressure. If the FWD cargo inlet temperature goes above 88 DEG.C (190.40 DEG.F) the pressure regulating valve 14HK will be closed. The pressure regulation is controlled pneumatically and a solenoid controls the on/off function. A limit switch indicates closed/not closed to the ACSC (47HH) and the ECAM system.
The pressure regulating-valve 14HK regulates the pressure of the air supplied to the trim-air valve 2HC. It performs the system shut-off function. The valve is a three-inch steel-butterflv type which is pneumatically actuated, and electrically signalled. The function of the valve is to act as an on/off valve for the trim-air system. It also regulates the downstream pressure to a nominal 280 mbar above cabin pressure. If the FWD cargo inlet temperature goes above 88 DEG.C (190.40 DEG.F) the pressure regulating valve 14HK will be closed. The pressure regulation is controlled pneumatically and a solenoid controls the on/off function. A limit switch indicates closed/not closed to the ACSC (47HH) and the ECAM system.
F. Pressure Regulating-Valve
The pressure regulating valve (11HC) is used to control the pressure of the hot trim air supply to 4 psi above cabin pressure. The secondary function is to provide a shut-off facility to the aft cargo compartment.
This butterfly type valve is under normal conditions actuated by a pneumatic actuator and controlled by a regulator. The valve is activated when the solenoid is energized.
The valve can be operated manually and includes a visual position indicator. A limit switch indicates closed/not closed to the zone controller (8HK) and to the ECAM system.
When the solenoid is energized, chamber C1 is subjected to upstream pressure through the restrictor G1. Chamber C2 is vented to the downstream pressure through the restrictor G2 and the open poppet valve C. The differential pressure between chambers C1 and C2 acts on the actuator piston to open the valve.
When the downstream pressure in chamber C3 reaches the set regulation value, the diaphragm M1 closes the poppet valve C. The pressure in chambers C4 and C2 increases (these two chambers are at the same pressure through the restrictor G2) to stop the valve opening. Downstream pressure in chamber C3 modulates the pressure in chambers C4 and C2 through the poppet valve C. The actuator piston position controlled by the pressure in chamber C2 corrects the butterfly valve opening to maintain downstream pressure at the set regulation value.
During the transient phase (when upstream pressure or flow changes), the diaphragm M2 acts on the the poppet valve C and controls the pressure variation speed in chamber C4 to avoid downstream pressure instability.
During the opening function, restrictor G1 reduces the pressure increase speed in chamber C1, while the opposite chamber C2 is subjected to upstream pressure through the check valve V1. This avoids downstream pressure surge during valve opening.
When the solenoid is deenergized, chamber C1 is vented more quickly through the restrictor G1 than chamber C2 through restrictor G2. Therefore the differential pressure C2-C1 added to the return spring effort moves the actuator piston to close the butterfly valve.
The inlet port to the regulator is designed to avoid ingestion of dust into the sensing line. It consists of a tube with two lateral orifices that face downstream to the airflow, which senses the inlet pressure.
The outlet port vents the regulator to the outlet duct of the valve, whose pressure is used as a measure of regulated pressure. This venting is done through lateral holes of a venturi positioned after the butterfly valve to compensate for turbulence and variations in the airflow.
The pressure regulating valve (11HC) is used to control the pressure of the hot trim air supply to 4 psi above cabin pressure. The secondary function is to provide a shut-off facility to the aft cargo compartment.
This butterfly type valve is under normal conditions actuated by a pneumatic actuator and controlled by a regulator. The valve is activated when the solenoid is energized.
The valve can be operated manually and includes a visual position indicator. A limit switch indicates closed/not closed to the ACSC (47HH) and to the ECAM system.
When the solenoid is energized, chamber C1 is subjected to upstream pressure through the restrictor G1. Chamber C2 is vented to the downstream pressure through the restrictor G2 and the open poppet valve C. The differential pressure between chambers C1 and C2 acts on the actuator piston to open the valve.
When the downstream pressure in chamber C3 reaches the set regulation value, the diaphragm M1 closes the poppet valve C. The pressure in chambers C4 and C2 increases (these two chambers are at the same pressure through the restrictor G2) to stop the valve opening. Downstream pressure in chamber C3 modulates the pressure in chambers C4 and C2 through the poppet valve C. The actuator piston position controlled by the pressure in chamber C2 corrects the butterfly valve opening to maintain downstream pressure at the set regulation value.
During the transient phase (when upstream pressure or flow changes), the diaphragm M2 acts on the the poppet valve C and controls the pressure variation speed in chamber C4 to avoid downstream pressure instability.
During the opening function, restrictor G1 reduces the pressure increase speed in chamber C1, while the opposite chamber C2 is subjected to upstream pressure through the check valve V1. This avoids downstream pressure surge during valve opening.
When the solenoid is deenergized, chamber C1 is vented more quickly through the restrictor G1 than chamber C2 through restrictor G2. Therefore the differential pressure C2-C1 added to the return spring effort moves the actuator piston to close the butterfly valve.
The inlet port to the regulator is designed to avoid ingestion of dust into the sensing line. It consists of a tube with two lateral orifices that face downstream to the airflow, which senses the inlet pressure.
The outlet port vents the regulator to the outlet duct of the valve, whose pressure is used as a measure of regulated pressure. This venting is done through lateral holes of a venturi positioned after the butterfly valve to compensate for turbulence and variations in the airflow.
The pressure regulating valve (11HC) is used to control the pressure of the hot trim air supply to 4 psi above cabin pressure. The secondary function is to provide a shut-off facility to the aft cargo compartment.
This butterfly type valve is under normal conditions actuated by a pneumatic actuator and controlled by a regulator. The valve is activated when the solenoid is energized.
The valve can be operated manually and includes a visual position indicator. A limit switch indicates closed/not closed to the zone controller (8HK) and to the ECAM system.
When the solenoid is energized, chamber C1 is subjected to upstream pressure through the restrictor G1. Chamber C2 is vented to the downstream pressure through the restrictor G2 and the open poppet valve C. The differential pressure between chambers C1 and C2 acts on the actuator piston to open the valve.
When the downstream pressure in chamber C3 reaches the set regulation value, the diaphragm M1 closes the poppet valve C. The pressure in chambers C4 and C2 increases (these two chambers are at the same pressure through the restrictor G2) to stop the valve opening. Downstream pressure in chamber C3 modulates the pressure in chambers C4 and C2 through the poppet valve C. The actuator piston position controlled by the pressure in chamber C2 corrects the butterfly valve opening to maintain downstream pressure at the set regulation value.
During the transient phase (when upstream pressure or flow changes), the diaphragm M2 acts on the the poppet valve C and controls the pressure variation speed in chamber C4 to avoid downstream pressure instability.
During the opening function, restrictor G1 reduces the pressure increase speed in chamber C1, while the opposite chamber C2 is subjected to upstream pressure through the check valve V1. This avoids downstream pressure surge during valve opening.
When the solenoid is deenergized, chamber C1 is vented more quickly through the restrictor G1 than chamber C2 through restrictor G2. Therefore the differential pressure C2-C1 added to the return spring effort moves the actuator piston to close the butterfly valve.
The inlet port to the regulator is designed to avoid ingestion of dust into the sensing line. It consists of a tube with two lateral orifices that face downstream to the airflow, which senses the inlet pressure.
The outlet port vents the regulator to the outlet duct of the valve, whose pressure is used as a measure of regulated pressure. This venting is done through lateral holes of a venturi positioned after the butterfly valve to compensate for turbulence and variations in the airflow.
The pressure regulating valve (11HC) is used to control the pressure of the hot trim air supply to 4 psi above cabin pressure. The secondary function is to provide a shut-off facility to the aft cargo compartment.
This butterfly type valve is under normal conditions actuated by a pneumatic actuator and controlled by a regulator. The valve is activated when the solenoid is energized.
The valve can be operated manually and includes a visual position indicator. A limit switch indicates closed/not closed to the ACSC (47HH) and to the ECAM system.
When the solenoid is energized, chamber C1 is subjected to upstream pressure through the restrictor G1. Chamber C2 is vented to the downstream pressure through the restrictor G2 and the open poppet valve C. The differential pressure between chambers C1 and C2 acts on the actuator piston to open the valve.
When the downstream pressure in chamber C3 reaches the set regulation value, the diaphragm M1 closes the poppet valve C. The pressure in chambers C4 and C2 increases (these two chambers are at the same pressure through the restrictor G2) to stop the valve opening. Downstream pressure in chamber C3 modulates the pressure in chambers C4 and C2 through the poppet valve C. The actuator piston position controlled by the pressure in chamber C2 corrects the butterfly valve opening to maintain downstream pressure at the set regulation value.
During the transient phase (when upstream pressure or flow changes), the diaphragm M2 acts on the the poppet valve C and controls the pressure variation speed in chamber C4 to avoid downstream pressure instability.
During the opening function, restrictor G1 reduces the pressure increase speed in chamber C1, while the opposite chamber C2 is subjected to upstream pressure through the check valve V1. This avoids downstream pressure surge during valve opening.
When the solenoid is deenergized, chamber C1 is vented more quickly through the restrictor G1 than chamber C2 through restrictor G2. Therefore the differential pressure C2-C1 added to the return spring effort moves the actuator piston to close the butterfly valve.
The inlet port to the regulator is designed to avoid ingestion of dust into the sensing line. It consists of a tube with two lateral orifices that face downstream to the airflow, which senses the inlet pressure.
The outlet port vents the regulator to the outlet duct of the valve, whose pressure is used as a measure of regulated pressure. This venting is done through lateral holes of a venturi positioned after the butterfly valve to compensate for turbulence and variations in the airflow.
6. Operation/Control and Indicating
Temperature Selector and Hot-Air Switch ** ON A/C NOT FOR ALL
Temperature Selector and Hot-Air Switch. ** ON A/C NOT FOR ALL
Temperature Selector and Hot-Air Switch ** ON A/C NOT FOR ALL Temperature Selector and Hot-Air Switch. ** ON A/C NOT FOR ALL A. Cargo-Compartment Temperature-Selector
The FWD cargo-compartment has a temperature selector 5HC which is installed on panel 22VU in the cockpit. The temperature in the FWD cargo compartment is controlled to between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) in heating mode. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
Turning the selector knob to the right or left will select any temperature between the above temperatures. When the selector knob is pointing to the 12 o'clock position, the temperature in the cargo compartment is selected to about 15.5 DEG.C (59.90 DEG.F). The temperature controller 1HC limit the temperature in the inlet duct to a maximum of 70 DEG.C (158.00 DEG.F)
The AFT cargo-compartment temperature-selector 15HC is installed on panel 22VU in the cockpit. The temperature in the AFT cargo compartment is controlled to between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) in heating mode. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
Turning the selector knob to the right or left will select any temperature between the above temperatures. When the selector knob is pointing to the 12 o'clock position, the temperature in the cargo compartment is selected to about 15.5 DEG.C (59.90 DEG.F). The heating controller 10HC limits the temperature in the inlet duct to a maximum of 70 DEG.C (158.00 DEG.F).
The FWD cargo-compartment has a temperature selector 5HC which is installed on panel 22VU in the cockpit. The temperature in the FWD cargo compartment is controlled to between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) in heating mode. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
Turning the selector knob to the right or left will select any temperature between the above temperatures. When the selector knob is pointing to the 12 o'clock position, the temperature in the cargo compartment is selected to about 15.5 DEG.C (59.90 DEG.F). The temperature controller 1HC limit the temperature in the inlet duct to a maximum of 70 DEG.C (158.00 DEG.F)
The AFT cargo-compartment temperature-selector 15HC is installed on panel 22VU in the cockpit. The temperature in the AFT cargo compartment is controlled to between 5 DEG.C (41.00 DEG.F) and 26 DEG.C (78.80 DEG.F) in heating mode. However, if the temperature is, for example, already 15 DEG.C (59.00 DEG.F), the adjusting range lies between 15 DEG.C (59.00 DEG.F) and 26 DEG.C (78.80 DEG.F).
Turning the selector knob to the right or left will select any temperature between the above temperatures. When the selector knob is pointing to the 12 o'clock position, the temperature in the cargo compartment is selected to about 15.5 DEG.C (59.90 DEG.F). The heating controller 10HC limits the temperature in the inlet duct to a maximum of 70 DEG.C (158.00 DEG.F).
B. Hot-Air Switch
The hot-air, which is supplied to the pressure regulating-valve 14HK, is unconditioned bleed-air from the downstream side of the flow control valves. The HOT-AIR switch (7HK), which is installed on panel 30VU in the cockpit, controls the pressure regulating-valve.
The hot-air supplied to the pressure regulating-valve 11HC is unconditioned bleed-air from the downstream side of the flow control valves. The HOT-AIR switch (16HC) installed on panel 22VU in the cockpit, controls the pressure regulating-valve.
The hot-air, which is supplied to the pressure regulating-valve 14HK, is unconditioned bleed-air from the downstream side of the flow control valves. The HOT-AIR switch (7HK), which is installed on panel 30VU in the cockpit, controls the pressure regulating-valve.
The hot-air supplied to the pressure regulating-valve 11HC is unconditioned bleed-air from the downstream side of the flow control valves. The HOT-AIR switch (16HC) installed on panel 22VU in the cockpit, controls the pressure regulating-valve.
C. Operation of the CC Heating System if there is a ventilation failure.
The ventilation controller 10HN sends a signal to the heating controller 1HC to close the trim air valve 2HC if there is (Ref. AMM D/O 21-28-00-00):
The ventilation controller 10HN sends a signal to the heating controller 1HC to close the trim air valve 2HC if there is (Ref. AMM D/O 21-28-00-00):
- a Fan Fault (6HN),
- an ISOL valve closed (4HN, 5HN).
- a Fan Fault (35HN),
- an ISOL valve closed (33HN, 34HN).
A. CHC Power-up Test
(1) Conditions of Power-up Test Initialization
(a) How long the computer must be de-energized:
- 200 ms
(b) A/C configuration:
- A/C on ground
(2) Progress of Power-up Test
(a) Duration:
- 28 s
(b) Cockpit repercussions directly linked to power-up test accomplishment (some other repercussions may occur depending on the A/C configuration but these can be ignored):
- Trim air valve cycling on ECAM system display
(3) Results of Power-up Test
(a) Test passed:
- none
(b) Test failed:
- ECAM warning:
COND FWD CRG HEAT FAULT - ECAM COND page:
hot air valve displayed in amber - Maintenance status:
FWD cargo heat
(4) Conditions of Power-up Test Initialization
(a) How long the computer must be de-energized:
- 200 ms
(b) A/C configuration:
- A/C on ground
(5) Progress of Power-up Test
(a) Duration:
- 28 s
(b) Cockpit repercussions directly linked to power-up test accomplishment (some other repercussions may occur depending on the A/C configuration but these can be ignored):
- Trim air valve cycling on ECAM system display
(6) Results of Power-up Test
(a) Test passed:
- none
(b) Test failed:
- ECAM warning:
COND AFT CRG HEAT FAULT - ECAM COND page:
hot air valve displayed in amber - Maintenance status:
AFT cargo heat
B. CFDS Maintenance Messages
(1) The FWD cargo-compartment heating-controller (1HC) sends failure data detected by its BITE to the Centralized Fault Display System (CFDS).
A possible failure can be class 1, class 2 or class 3.
A possible failure can be class 1, class 2 or class 3.
- A class 1 failure requires immediate maintenance action, as they always lead to a loss of the affected system with operational consequences.
- A class 2 failure will not lead to operational consequences but cannot be left uncorrected until the next scheduled maintenance check.
- Class 3 failure are failures which can be left uncorrected until the next scheduled maintenance check.
(2) The AFT cargo-compartment heating-controllers (10HC) sends failure data detected by its BITE to the Centralized Fault Display System (CFDS).
A possible failure can be class 1, class 2 or class 3.
A possible failure can be class 1, class 2 or class 3.
- A class 1 failure requires immediate maintenance action, as they always lead to a loss of the affected system with operational consequences.
- A class 2 failure will not lead to operational consequences but cannot be left uncorrected until the next scheduled maintenance check.
- Class 3 failure are failures which can be left uncorrected until the next scheduled maintenance check.
(3) Class 3 Maintenance Messages
| ------------------------------------------------------------------------------- |
| | BITE TEST |
| |-----------------------------------------------------------------------------| |
| | INDICATION ON THE MCDU | ATA REF. | BITE DETECTION | |
| ------------------------------------------------------------------------------- |
| FWD TEMP SELECTOR 21-43-16 TEMP SELECTOR RANGE |
| FWD CARGO HEAT CONT 21-43-34 TEMP SELECTOR INTERFACE |
| PIN PROGR. "A" INP. INTERFACE |
| PIN PROGR. "B" INP. INTERFACE |
| FWD CODING |
| SHOP CODING |
| NO DATA FROM CFDS 31-32-34 ARINC INPUT |
(4) Class 3 Maintenance Messages
| ------------------------------------------------------------------------------- |
| | BITE TEST |
| |-----------------------------------------------------------------------------| |
| | INDICATION ON THE MCDU | ATA REF. | BITE DETECTION | |
| ------------------------------------------------------------------------------- |
| AFT TEMP SELECTOR 21-43-16 TEMP SELECTOR RANGE |
| AFT CARGO HEAT CONT 21-43-34 TEMP SELECTOR INTERFACE |
| PIN PROGR. "A" INP. INTERFACE |
| PIN PROGR. "B" INP. INTERFACE |
| AFT CODING |
| SHOP CODING |
| NO DATA FROM CFDS 31-32-34 ARINC INPUT |
(5) Class 2 Maintenance Messages
| ------------------------------------------------------------------------------- |
| | BITE TEST |
| |-----------------------------------------------------------------------------| |
| | INDICATION ON THE MCDU | ATA REF. | BITE DETECTION | |
| ------------------------------------------------------------------------------- |
| AFT TAPRV SHUT OFF RELAY 21-43-00 AFT TAPRV A. C. SHUT OFF RELAY |
| AFT PRESSURE REG VALVE 21-43-52 AFTER TAPRV MOVEMENT |
(6) Class 1 Maintenance Messages
| ------------------------------------------------------------------------------- |
| | BITE TEST |
| |-----------------------------------------------------------------------------| |
| | INDICATION ON THE MCDU | ATA REF. | BITE DETECTION | |
| ------------------------------------------------------------------------------- |
| FWD DUCT TEMP SENSOR 21-43-15 DUCT SENSOR RANGE |
| COMP SENSOR RANGE |
| FWD CARGO HEAT CONT 21-43-34 RAM 0 DATA |
| RAM 1 DATA |
| EPROM DATA |
| ARINC OUTPUT |
| DUCT SENSOR INTERFACE |
| COMP SENSOR INTERFACE |
| TAV POS. SENSOR INTERFACE |
| A/D CONVERTER |
| STEPP. MOT. INTERFACE PHASE "A" |
| STEPP. MOT. INTERFACE PHASE "B" |
| STEPP. MOT. INTERFACE PHASE "C" |
| STEPP. MOT. INTERFACE PHASE "D" |
| CARGO DOOR NFC INP. INTERFACE |
| TAV NFC INPUT INTERFACE |
| TAV NFO INPUT INTERFACE |
| ISOL. V. FC INPUT INTERFACE |
| RESETT/OFF INPUT INTERFACE |
| FAN FAULT INP. INTERFACE |
| TAPRV FC INPUT INTERFACE |
| CONTR. FAULT OUTP. INTERFACE |
| OVHT OUTP. INTERFACE |
| TAPRV AUTO CLOSE OUTP. INTERFACE |
| FWD TRIM AIR VALVE 21-43-53 TAV MOTOR |
| TAV MOVEMENT |
| TAV CLOSURE SPRING |
(7) Class 1 Maintenance Messages
| ------------------------------------------------------------------------------- |
| | BITE TEST |
| |-----------------------------------------------------------------------------| |
| | INDICATION ON THE MCDU | ATA REF. | BITE DETECTION | |
| ------------------------------------------------------------------------------- |
| AFT DUCT TEMP SENSOR 21-43-15 DUCT SENSOR RANGE |
| COMP SENSOR RANGE |
| AFT CARGO HEAT CONT 21-43-34 RAM 0 DATA |
| RAM 1 DATA |
| EPROM DATA |
| ARINC OUTPUT |
| DUCT SENSOR INTERFACE |
| COMP SENSOR INTERFACE |
| TAV POS. SENSOR INTERFACE |
| A/D CONVERTER |
| STEPP. MOT. INTERFACE PHASE "A" |
| STEPP. MOT. INTERFACE PHASE "B" |
| STEPP. MOT. INTERFACE PHASE "C" |
| STEPP. MOT. INTERFACE PHASE "D" |
| CARGO DOOR NFC INP. INTERFACE |
| TAV NFC INPUT INTERFACE |
| TAV NFO INPUT INTERFACE |
| ISOL. V. FC INPUT INTERFACE |
| RESETT/OFF INPUT INTERFACE |
| FAN FAULT INP. INTERFACE |
| BULK CARGO DOOR FC INP. INTERFACE |
| TAPRV FC INPUT INTERFACE |
| CONTR. FAULT OUTP. INTERFACE |
| OVHT OUTP. INTERFACE |
| TAPRV AUTO CLOSE OUTP. INTERFACE |
| AFT TRIM AIR VALVE 21-43-51 TAV MOTOR |
| TAV MOVEMENT |
| TAV CLOSURE SPRING |