Bombardier DHC 8-400 (PWC PW150) ATA 29 - Hydraulic Power PDF

BOMBARDIER DHC 8-400 (PWC PW150) ATA 29 - HYDRAULIC POWER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY B1/B2 MAINTENANCE TRAINING MANUAL Issue 6 - January 2023 Page 1 of 104 BOMBARDIER DHC 8-400 (PWC PW150) • • • HYDRAULIC POWER PURPOSE The main and auxiliary hydraulic systems supply the...

BOMBARDIER DHC 8-400 (PWC PW150) ATA 29 - HYDRAULIC POWER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY B1/B2 MAINTENANCE TRAINING MANUAL Issue 6 - January 2023 Page 1 of 104 BOMBARDIER DHC 8-400 (PWC PW150) • • • HYDRAULIC POWER PURPOSE The main and auxiliary hydraulic systems supply the fluid force necessary to achieve the mechanical advantage necessary to move the hydraulically assisted devices. INTRODUCTION The Dash 8 Q400 has four hydraulic systems, three main systems, and an auxiliary system. The No.1 and No.2 independent main hydraulic systems provide power to operate the: • • • • Flight Controls Landing Gear Nose Wheel Steering Brake Systems Parking brakes Rudder (Upper PCU) Elevators (Centre PCU) The No.3 system supplies backup hydraulic power to the elevators. • • Left Elevator (Inboard PCU) Right Elevator (Inboard PCU) The auxiliary hydraulic system is provided as an alternate landing gear extension system. It supplies hydraulic power to extend the main landing gears when main hydraulic power is not available. A hand pump is used to manually pump up the hydraulic pressure in the auxiliary system, if the landing gear LEFT and/or RIGHT green locked down advisory lights do not come on. All systems use a synthetic phosphate ester-based fluid. The hydraulic system contains these systems: The No.3 main hydraulic system provides power to operate the elevator. The auxiliary hydraulic system provides power to operate the main landing gear to the down and locked position. • • • • No.1 and No.2 Main Hydraulic Systems No.3 Main Hydraulic System Alternate Landing Gear Extension Hydraulic System Indicating GENERAL DESCRIPTION The No.1 system powers these systems: • • • • • Flaps Inboard roll spoilers Main wheel brakes Rudder (Lower Power Control Unit PCU) Elevators (Outboard PCU) The No.2 system powers these systems: • • • Landing gear Nose wheel steering Outboard roll spoilers TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 2 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - SIMPLIFIED HYDRAULIC SYSTEMS BLOCK DIAGRAM TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 3 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER GENERAL DESCRIPTION Main hydraulic power is provided by three independent hydraulic systems, designated No.1 (left), No.2 (right) and No.3 (aft). The No.1 and No.2 hydraulic systems are normally pressurized by a single Engine-Driven Pump (EDP) for each system. System pressure is maintained at 3000 psi (20684 kPa). An electrically driven Standby Power Unit (SPU) operates as a backup to the No.1 hydraulic system. The SPU operates during the takeoff and landing phases, or if the No.1 EDP fails. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 4 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - SIMPLIFIED HYDRAULIC SYSTEM No.1 DETAIL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 5 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER GENERAL DESCRIPTION A Power Transfer Unit (PTU) operates as a backup to the No.2 hydraulic system in the landing and take-off phases, or if No.2 EDP or No.2 engine fails. The PTU is powered by the No.1 hydraulic system. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 6 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - SIMPLIFIED HYDRAULIC SYSTEM No.2 DETAIL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 7 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER GENERAL DESCRIPTION The No.3 hydraulic system is powered by an accumulator that is pressurized by a DCMotor-Driven-Pump (DCMP). A pressure switch controls the DCMP operation to keep the accumulator pressure to within 2600 to 3250 psi (17926 to 22407 kPa). The No.3 main hydraulic system supplies pressure to the left and right elevators if the No.1 and/or No.2 hydraulic system(s) fail. The auxiliary hand operated hydraulic system provides power to the alternate main landing gear extension system. If a dual engine failure occurs, where both EDP and the SPU are unavailable, the DCMP in No.3 hydraulic system provides sufficient hydraulic power to the elevators for pitch control. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 8 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - SIMPLIFIED HYDRAULIC SYSTEM No.3 DETAIL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 9 of 104 BOMBARDIER DHC 8-400 (PWC PW150) • • HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS Only the No.1 hydraulic system has these components: PURPOSE • • • The No.1 and No.2 hydraulic systems supply hydraulic power to: • • • • 225°F/107°C Temperature Switch 275°F/135°C Temperature Switch No.1 Hydraulic System Reservoir Standby Power Unit No.1 Hydraulic System Port-Mounted Check Valve Only the No.2 hydraulic system has these components: Flight controls Landing gear Brakes Nose wheel steering • • • No.2 Hydraulic System Reservoir Power Transfer Unit Hydraulic PTU Select Valve GENERAL DESCRIPTION No.1 and No.2 hydraulic systems have the necessary components for supplying clean, temperature and pressure regulated hydraulic fluid. Hydraulic fluid contamination is controlled by the No.1 and No.2 hydraulic system filter manifolds. Each hydraulic system has an oil-to-fuel heat exchanger in each wing tank for cooling of the hydraulic fluid. Each system has an electrically powered firewall shut-off valve installed in the EDP suction line. This valve stops the flow of fluid to the hydraulic system if an engine shutdown, fire or hydraulic emergency occurs. Both No.1 and No.2 hydraulic systems contain these components: • • • • • • • • • • • Engine-Driven Pumps Firewall Shut-off Valves Isolation Valves Ecology Bottles Filter Manifolds Pressure Filter Elements Return Filter Elements Case-Drain Filter Elements Heat Exchangers Heat Exchanger Bypass Valves No.1 Hydraulic System Balanced Relief Valve TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 10 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC COMPONENTS, LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 11 of 104 BOMBARDIER DHC 8-400 (PWC PW150) • • • HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS Inbd Spoiler PCUs Flaps PTU Input Power A reservoir level sensing valve ports pilot pressure to an isolation valve. SIMPLIFIED DESCRIPTION NO.1 MAIN HYDRAULIC SYSTEM Primary hydraulic pressure is supplied to the No.1 hydraulic system by an EngineDriven Pump (EDP). Secondary hydraulic pressure for the No.1 system is supplied by a Standby Power Unit (SPU). The SPU is powered by the 115V AC Variable Frequency right bus, with backup power supplied by the left bus. The No.1 hydraulic system supplies input power to the PTU pump. This PTU pump pressurizes the No.2 hydraulic system. A 8 US qts boot strap reservoir provides 55 psi into the suction line inlet pressure through a FSOV to an EDP or directly to an SPU. The reservoir quantity transducer displays No.1 HYD QTY on the No.2 MFD. The reservoir also contains a direct reading gauge. Provisions for bleed/relief/sample are provided and contained in the nacelle by an ecology bottle. Low reservoir quantity detected by the level sensing valve stops pilot pressure to the isolation valve. The isolation valve closes under spring pressure and isolates the system pressure to the lower rudder PCU, L/R outbd elevator PCUs, flaps, and the PTU input power. The No.1 HYD ISO VLV caution light monitors pressure switches depicting isolation valve port input and output pressure. A priority valve will spring load close if fluid pressure becomes low. This stops system pressure to the flaps and PTU and will automatically reset when fluid pressure returns to high. Hot case drain fluid is cooled by a thermal bypass valve and an oil/fuel heat exchanger, installed in the wing tank collector bay. This fluid is then returned to the reservoir where two fluid temperature switches monitor the hydraulic fluid temperature. A No.1 HYD FLUID HOT caution light monitors the reservoir fluid over-temperature switch. If the hydraulic fluid temperature continues to rise, the second over-temperature switch will logic the FSOV closed. Port mounted check valves direct pump output pressure through a filter manifold. The filter manifold removes contaminates from fluid pressure, fluid return, and fluid case drain. The filter manifold contains two pressure T/Xs; one for EDP and the other for STBY pressure display on the No.2 MFD. The No.1 ENG HYD PUMP caution light monitors a filter manifold mounted pressure s/w for EDP low output pressure. A filter manifold pressure relief valve relieves excess pressure to return. The No.1 STBY HYD PUMP HOT caution light monitors the SPU motor windings thermal s/w for overheat. System pressure is supplied to the following: • • • Lower Rudder PCU L/R Outbd Elevator PCUs Normal Brakes TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 12 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.1 HYDRAULIC SYSTEM SYNOPTIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 13 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER The isolation valve then spring-loads to close and isolates the system pressure to the upper rudder PCU and left/right and centre elevator PCUs. NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS The No.2 HYD ISO VLV caution light monitors pressure switches depicting isolation valve port input and output pressure. SIMPLIFIED DESCRIPTION CONTINUED NO.2 MAIN HYDRAULIC SYSTEM Primary hydraulic pressure is supplied to the No.2 hydraulic system by an EngineDriven Pump (EDP). Secondary hydraulic pressure for the No.2 system is supplied by the Power Transfer Unit (PTU). The No.1 hydraulic system supplies input power to the PTU pump. This PTU pump pressurizes the No.2 hydraulic system. A 12 US qts boot-strap reservoir provides 55 psi pressure into the suction line through a FSOV to an EDP or directly to a PTU. The reservoir quantity transducer displays No.2 HYD QTY on the No.2 MFD. The reservoir also contains a direct reading gauge. Provisions for bleed/relief/sample are provided and contained in the nacelle by an ecology bottle. Hot case drain fluid is cooled by a thermal bypass valve and a oil/fuel heat exchanger mounted in the wing tank collector bay. This fluid is then returned to the reservoir where two fluid temperature switches monitor the hydraulic fluid temperature. A No.2 HYD FLUID HOT caution light monitors the reservoir fluid over-temperature switch. If the hydraulic fluid temperature continues to rise, the second over-temperature switch will logic the FSOV closed. Provision for refill and ground cart operations are provided at the filter manifold. Access to these quick disconnect ports are provided at the nacelle hydraulic service door. A port mounted check valve directs pump output pressure through a filter manifold. The filter manifold removes contaminates from fluid pressure, fluid return, and fluid case drain. The filter manifold contains one pressure T/X and displays system pressure on the No.2 MFD. The No.2 ENG HYD PUMP caution light monitors a filter manifold mounted pressure s/w for EDP low output pressure. A filter manifold pressure relief valve relieves excess pressure to return. System pressure is supplied to the following: • • • • • • Upper Rudder PCU L/R Centre Elevator PCUs Emergency/Parking Brake Outbd Spoiler PCUs Landing Gear Ext/Ret Nose Wheel Steering A reservoir level sensing valve ports pilot pressure to an isolation valve. Low reservoir quantity detected by the level sensing valve stops pilot pressure to the isolation valve. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 14 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.2 HYDRAULIC SYSTEM SYNOPTIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 15 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS ENGINE-DRIVEN PUMPS PURPOSE Each pump supplies full, primary system pressure of 3000 psi (20684 kPa). Each Engine-Driven Pump (EDP) is a variable displacement pressure compensated multi-piston hydraulic pump. The pumps vary the fluid flow volume to maintain optimum system pressure. The suction, pressure and case drain ports of the pumps are connected by flexible hoses to the hydraulic systems. The EDPs are installed on the reduction gearbox of both the No.1 and No.2 engines. The pumps are flange attached by studs, washers and nuts. The pumps are splined to the reduction gearbox. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 16 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ENGINE DRIVEN PUMP (EDP) TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 17 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS FIREWALL SHUT-OFF VALVES PURPOSE The Firewall Shut-Off Valves (FSOVs) stop the flow of hydraulic fluid to the EDP. The primary function of the FSOV is to prevent hydraulic fluid from being delivered forward of the firewall in the event of an engine fire. DESCRIPTION The hydraulic Firewall Shut-Off Valves (FSOV) are installed in the No.1 and No.2 engine nacelles wheel-well forward-right sidewall, in the EDP suction line. Each FSOV is a DC motor driven ball-type shut-off valve. Each FSOV has an open/ closed red pencil position indicator. The Firewall Shutoff Valve is powered by the battery bus. Two VALVES HYD advisory lights for each firewall shut off valve are provided on the Fire Protection Panel, one green and one white. The green advisory light comes on when the firewall valve is OPEN. The white advisory comes on when the valve is CLOSED. The FSOV stop the flow of hydraulic fluid to the EDP if any of the following conditions exist: • • • Fire protection panel PULL FUEL/HYD OFF handle - Pulled Hydraulic reservoir level sensing switch - Empty reservoir Hydraulic reservoir fluid over-temperatures - 225°F/107°C and 275°F/135°C TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 18 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - VALVE, FIREWALL SHUTOFF TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 19 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS RESERVOIRS PURPOSE The hydraulic system reservoirs store hydraulic fluid and supply the necessary fluid volume to the hydraulic systems. The No.1 hydraulic system reservoir is installed in the No.1 engine nacelle wheel-well mid-right sidewall. The No.2 hydraulic system reservoir is installed in the No.2 engine nacelle wheel-well mid-right sidewall. The reservoir uses system output pressure 3000 psi (20684 kPa) to pressurize the differential piston. This provides bootstrapping at 55 psi (379 kPa) suction pressure to the EDP. A pressure bleed/relief valve is installed in the reservoir to supply pressure relief of the hydraulic system at 80 psi (552 kPa). The bleed/relief valve may also be manually opened to bleed air from the reservoir or to take a hydraulic fluid sample. A quantity transducer is installed on each hydraulic system reservoir. The quantity transducer sends an electrical signal to the flight data processing system. These signals are processed and displayed as No.1 HYD QTY and No.2 HYD QTY on the multi-function display (MFD No.2). The volume of the No.1 system reservoir is 8 US qts/7.57 L. The volume of the No.2 system reservoir is 12 US qts/11.4 L. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 20 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC RESERVOIRS LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 21 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS RESERVOIRS CONTINUED PURPOSE The No.1 and No.2 hydraulic systems each contain a 225°F/107°C and a 275°F/135°C) temperature switch, installed on the hydraulic system reservoir. The switches monitor the temperature of the hydraulic fluid inside the reservoir. If fluid temperature reaches 225°F/107°C the switch causes the No.1 or No.2 HYD FLUID HOT caution light. If fluid temperature reaches 275°F/135°C, the temperature switches causes the firewall shut-off valve to close. The reservoir includes a normally open, 3-position reservoir level sensing valve. The level sensing valve is operated by the reservoir piston head. This valve controls pilot pressure for operating the isolation valve. At normal levels the valve is open and supplies pilot pressure to the isolation valve. At lower than expected levels the piston head closes the level sensing valve pilot port to the isolation valve. At near zero reservoir quantities the system is assumed to have failed completely, or the system is being operated from a ground cart. The level sensor now opens again, allowing complete hydraulic system service. When empty, the reservoir level sensing valve also actuates a reservoir empty level sensing switch. This switch closes the firewall shut-off valve and logics the SPU and PTU off. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 22 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - RESERVOIR LEVEL AND TEMPERATURE SENSING TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 23 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS ISOLATION VALVES PURPOSE The normally open isolation valve stops the flow of hydraulic fluid to part of the hydraulic system if the reservoir contents drop below 80 in³/1311 cm³. The No.1 and No.2 hydraulic systems each include an isolation valve installed in each fuselage to wing fairing. The isolation valve is operated by spring force. It is controlled by pilot pressure. The pilot pressure port is controlled by a reservoir level sensing valve, installed in the reservoirs. Two pressure switches are installed on each hydraulic system isolation valve. These pressure switches monitor hydraulic pressure at the inlet and outlet ports of the isolation valve. When pressure is sensed at the inlet pressure switch, but not at the outlet, the No.1 or No.2 HYD ISO VLV caution light comes on. No.1 hydraulic system isolation allows fluid flow to these components (only): • • • • Flaps PTU Rudder Elevators No.2 hydraulic system isolation allows fluid flow to these components (only): • • Rudder Elevators TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 24 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ISOLATION VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 25 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER These check valves prevent the fluid from the outlet of one pump from flowing into the outlet of the other. NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS The No.1 hydraulic system filter manifold has two pressure transmitters. FILTER MANIFOLDS No.1 EDP pressure displays on the HYD PRESS indicator as No.1. The SPU pressure on displays on the HYD PRESS indicator as STBY and No.1. PURPOSE The primary function of the filter manifold is to remove contaminates from the pressure, return, case drain, filling and ground power fluid circuits. The filter manifold is also the supply point for flow from the pumps and the collection point for return flow from the system to the reservoir. The No.1 and No.2 hydraulic systems each include a filter manifold. The hydraulic system filter manifolds are installed in the engine nacelle wheel-well mid-right sidewall. A Differential Pressure Indicator (DPI) is installed for each of the filter bowls on the filter manifold. A red indicator extends to give a visual warning of clogged filter elements or large fluid pressure drops across the filters. The No.2 hydraulic system filter manifold has one port mounted check valve and one pressure transmitter. No.2 system pressure displays on the HYD PRESS indicator as No.2 regardless of the source. Each hydraulic system filter manifold has an EDP pressure switch upstream of the port mounted check valve. This pressure switch monitors the pressure output from the EDP. If the EDP fails, the No.1 or No.2 ENG HYD PUMP caution light comes on. Each hydraulic system filter manifold includes a pressure relief valve. This pressure relief valve relieves excess manifold pressure to return. Each hydraulic system filter manifold includes quick disconnect couplings for servicing and ground cart operation. One pressure filter is installed in each filter manifold. The filter element removes 100% of all contamination particles larger than 5 microns. The filter elements are disposable. One return filter is installed in each filter manifold. The filter element removes 100% of all contamination particles larger than 5 microns. The filter elements are disposable. One case-drain filter is installed in each filter manifold. The filter elements remove 100% of all contamination particles larger than 15 microns. The filter elements are disposable. The No.1 hydraulic system filter manifold assembly contains two port mounted check valves. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 26 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC FILTER MANIFOLD TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 27 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS STANDBY POWER UNIT PURPOSE No.1 hydraulic system uses a variable frequency AC motor-driven pump standby power unit (SPU) which functions as a backup source for No.1 main hydraulic system. The SPU is installed in the No.1 nacelle upper mid-wheel-well. The SPU supplies backup power to the No.1 hydraulic system and is selected on for takeoff and landing. The SPU is electrically powered by the right 115V AC bus. Backup electrical power to the SPU is supplied by the left 115V AC bus. A thermal switch monitors the SPU motor windings. The No.1 STBY HYD PUMP HOT caution light comes on if an overheat condition is detected. The SPU is normally selected on for takeoff and landing. When the STBY HYD PRESS switch-light on the HYDRAULIC CONTROL panel is pushed, the SPU is energized on and green ON legend in the switch-light comes on. When the SPU is activated on automatically, the green ON legend in the switch-light does not come on. After takeoff, the STBY HYD PRESS switch is selected off to deactivate the SPU. Nominal system pressure is 3000 psi (20684 kPa). If not selected on, the SPU will automatically be energized if: • • No.1 engine fails during flight detected by low oil pressure switch Flaps are selected to positions greater than 0° when the parking brakes are selected off if hydraulic reservoir No.1 is not empty TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 28 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - STANDBY POWER UNIT (SPU) TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 29 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS ECOLOGY BOTTLES PURPOSE The ecology bottles collect pump leakage. DESCRIPTION The No.1 hydraulic system ecology bottle and the SPU ecology bottle are installed in the No.1 engine nacelle wheel-well mid-right sidewall. The No.1 ecology bottle collects leakage from the No.1 reservoir bleed/relief valve and the balanced relief valve. The SPU ecology bottle collects leakage from the SPU shaft seal. The No.2 hydraulic system ecology bottle is installed in the No.2 engine nacelle wheelwell mid-right sidewall and collects drainage from the No.2 reservoir bleed/relief valve. Each bottle has a fluid capacity of 0.793 US qts/750 millilitres. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 30 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ECOLOGY BOTTLE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 31 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS HEAT EXCHANGER BYPASS VALVES PURPOSE The heat exchanger bypass valve controls the flow of hydraulic fluid from the pumps case-drain to the heat exchanger. DESCRIPTION The heat exchanger bypass valve is installed between the heat exchanger inlet and outlet line on each of the No.1 and No.2 engine nacelles right mid-wheel-well. The valve controls the flow of hydraulic fluid from the pumps case-drain to the heat exchanger as a function of fluid temperature. The valve also functions as a relief valve to let fluid bypass the heat exchanger if the pressure differential increases above 85 psid. The valve reseats below 85 psid. The valve starts to open at 95°F/35°C and is fully open at 125°F/52°C. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 32 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HEAT EXCHANGER BYPASS VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 33 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS HEAT EXCHANGERS PURPOSE The hydraulic fluid heat exchangers cool the hydraulic fluid in the No.1 and No.2 hydraulic systems. DESCRIPTION The No.1 and No.2 hydraulic systems each have an oil-to-fuel heat exchanger located in the fuel tank. Hydraulic fluid from pump case drain, flows through the heat exchanger before returning to the hydraulic reservoir. A heat exchanger bypass valve controls the flow of hydraulic fluid to and from the heat exchanger. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 34 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC HEAT EXCHANGER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 35 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS HYDRAULIC SYSTEM NO.1 BALANCED RELIEF VALVE PURPOSE The balance relief valve removes hydraulic power to the flaps and PTU to maintain operation of the elevators, rudder, I/B spoilers and brakes if hydraulic system No.1 pressure drops significantly. The No.1 hydraulic system balanced relief valve or priority valve is located in the rear left fuselage-to-wing fairing. The priority valve is normally open. If the hydraulic pressure in No.1 system decreases below 2100 psi (14478 kPa) because of system demand, the priority valve closes. This shuts off hydraulic power to the flaps and PTU. Hydraulic pressure is maintained to the elevators, rudder, inboard spoilers and brakes. The priority valve automatically opens when the No.1 system pressure increases to 2100 psi (14478 kPa). TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 36 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - BALANCED RELIEF (PRIORITY) VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 37 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS POWER TRANSFER UNIT (PTU) PURPOSE The Power Transfer Unit (PTU) is a fixed displacement device used to supply backup hydraulic pressure to the No.2 hydraulic system from the No.1 hydraulic system. The PTU is installed in the fuselage-to-wing fairing rear-right. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 38 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - PTU LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 39 of 104 BOMBARDIER DHC 8-400 (PWC PW150) • HYDRAULIC POWER No.1 EDP is more than 2400 psi (16547 kPa) NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS POWER TRANSFER UNIT (PTU) CONTINUED PURPOSE A Power Transfer Unit (PTU) operates as a backup hydraulic pressure source to the No.2 hydraulic system during takeoff, landing and periods of high system flow demand. The PTU uses hydraulic pressure from the No.1 system to power the hydraulic motor side of the PTU. The motor then operates the hydraulic pump side to pressurize the No.2 system. Hydraulic fluid is not shared or transferred between No.1 and No.2 hydraulic systems during PTU operation. Hydraulic fluid must be available in the No.2 system for PTU operation. The PTU has a bypass orifice to maintain a steady rotation under no flow demands. This bypass flow is ported through the case drain circuit to the system heat exchanger to offset the additional heat created by PTU operation. The PTU displacement ratio is balanced flow/pressure to achieve delivery pressure similar to the EDP throughout the required range. The PTU may be selected on manually, or is actuated automatically during take off and approach. Manual selection of the PTU is by pushing the PTU CNTRL switch-light on the HYDRAULIC CONTROL panel. A pressure switch is installed in the No.2 hydraulic system, down-steam from the PTU. The PTU green ON legend in the switch-light comes on if the pressure switch senses pressure at the PTU discharge port. Automatic actuation of the PTU occurs when: • • • The park brake is selected off Flaps are selected greater than 0° Hydraulic No.2 reservoir is not empty TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 40 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - PTU HYDRAULIC SYNOPTIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 41 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS POWER TRANSFER UNIT (PTU) CONTINUED PTU SELECT VALVE PURPOSE The solenoid-operated PTU select valve controls the PTU motor. DESCRIPTION The PTU select valve is installed in the fuselage to wing fairing rear left. Manual or automatic PTU system activation energizes the PTU select valve solenoid. The PTU select valve is a 3-way, 2-position, pilot-operated spool valve. The valve is normally closed and pressure operated to the open position. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 42 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - PTU SELECTOR VALVE LOCATOR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 43 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.1 AND NO.2 MAIN HYDRAULIC SYSTEMS SERVICING RESERVOIRS Reservoir filling instructions are printed on labels attached to each reservoir. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 44 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.1 RESERVOIR FILLING INSTRUCTIONS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 45 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.2 RESERVOIR FILLING INSTRUCTIONS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 46 of 104 BOMBARDIER DHC 8-400 (PWC PW150) INTENTIONALLY LEFT BLANK TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 47 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER PCU from hydraulic pressure. Only two of the three hydraulic systems are needed to provide full elevator control authority. NO.3 MAIN HYDRAULIC SYSTEM PURPOSE The No.3 main hydraulic system supplies emergency hydraulic power to the elevators. GENERAL DESCRIPTION The No.3 hydraulic system is installed in the aft fuselage. The No.3 main hydraulic system supplies emergency hydraulic power to the elevators. During normal flight operation, the system is in an active standby mode with the accumulator isolation valve closed. The DCMP operates intermittently to keep the system pressurized to within the range of 2600 to 3250 psi (17926 kPa to 22407 kPa). When the pressure switches in the system No.1 and No.2 isolation valves indicate that either one or both systems have failed, they send a signal to the system 3 accumulator isolation valve commanding it to open. The isolation valve includes a pressure transducer which sends a system pressure signal to the Flight Data Processing System (FDPS). The FDPS converts the signal to digital format for display on the MFD. Since the transducer is on the downstream side of the valve, the MFD normally indicates 0 psi for system No.3. The system operates automatically during an emergency condition when the No.1 and/or No.2 hydraulic systems are unavailable, or when both engines indicate low oil pressure. The No.3 hydraulic system can also be engaged manually when the HYD No.3 ISOL VLV switch, located on the HYDRAULIC CONTROL Panel in the flight compartment is set to OPEN. The No.3 hydraulic system uses an accumulator which is pressurized by a DC Motor Driven Pump (DCMP). The No.3 hydraulic system has these components: • • • • • • • • Accumulator DCMP Accumulator Isolation Valve Reservoir Pressure Filter Ecology Bottle Pressure Switches Accumulator Manifold Charging Gauge SIMPLIFIED DESCRIPTION An accumulator isolation valve is included in the system to isolate the system No.3 TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 48 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC SYSTEM SCHEMATIC TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 49 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM ACCUMULATOR PURPOSE The No.3 hydraulic system accumulator keeps the system pressurized during normal flight operation. The accumulator is charged with dry nitrogen gas. An accumulator charging manifold has a service port to charge the accumulator. The accumulator is sized primarily to minimize the DCMP duty cycle and to accommodate transients due to large elevator control inputs The servicing instructions for the accumulator are located on a decal which is adjacent to the accumulator. A service placard, attached to the charging manifold, provides accumulator charging instructions. Access to the charging-gauge manifold is through a door on the bottom of the rear fuselage. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 50 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC SYSTEM ACCUMULATOR, GAUGE AND SERVICING DECAL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 51 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM DCMP PUMP PURPOSE The DC Motor Pump (DCMP) is used in the No.3 hydraulic system, with the accumulator, to pressurize the No.3 system. System pressure is developed by a DC motor driven, fixed displacement piston pump (DCMP). The motor is powered by the Standby Battery via the Standby Contactor Box, which remains available following loss of all electrical power from the aircraft generators. The DCMP will operate intermittently during normal flight, or with engine(s) running on ground, to maintain a No.3 system pressure range of 2600 to 3250 psi (17926 kPa to 22407 kPa). TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 52 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - DC MOTOR PUMP TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 53 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM ACCUMULATOR ISOLATION VALVE PURPOSE An isolation valve is used to isolate the elevators from the No.3 hydraulic system. The No.3 hydraulic system isolation valve is closed energized during normal flight operation. When open, the isolation valve allows hydraulic pressure to power the elevators. The isolation valve will open in flight if the No.1 and/or No.2 hydraulic system pressure is low or if the No.1 and No.2 engine oil pressure is low. The isolation valve can be manually opened from the flight compartment when the HYD No.3 ISOL VLV switch on the HYDRAULIC CONTROL Panel is set to OPEN. The isolation valve also includes a system pressure relief/dump valve on the upstream side of the isolation valve to prevent system over-pressurization should the DCMP fail to shut off. The relief/dump valve is a button which allows ground crew to manually dump accumulator pressure during maintenance action. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 54 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC SYSTEM ACCUMULATOR ISOLATION VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 55 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM RESERVOIR PURPOSE The reservoir stores hydraulic fluid for No.3 hydraulic system and provides local and remote fluid quantity indication. DESCRIPTION Fluid is provided to the DCMP by a bootstrap-type reservoir nominally pressurized to 55 psi. The quantity indication is controlled by a cable which is attached to the reservoir piston. As the piston moves due to changing fluid quantity, the cable rotates the shaft of a potentiometer. The potentiometer transmits a quantity signal to the Flight Data Processing System (FDPS). The FDPS converts the signal to a digital format for display on the MFD. The cable also rotates the graduated drum of a quantity gauge mounted onto the reservoir. A bleed/relief valve is installed in the reservoir to provide manual bleeding and pressure relief of the hydraulic system. The volume of the No.3 hydraulic system reservoir is 150 in³/2458 cm³. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 56 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC RESERVOIR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 57 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM RESERVOIR CONTINUED DESCRIPTION The No.3 hydraulic system reservoir filling instructions are on a decal which is attached to the reservoir. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 58 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC RESERVOIR FILLING INSTRUCTIONS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 59 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM PRESSURE FILTER PURPOSE The No.3 hydraulic system pressure filter assembly filters the supply pressure fluid coming from the DCMP. DESCRIPTION The No.3 hydraulic system pressure filter is located in the aft fuselage section in line between the DCMP and the accumulator. The No.3 hydraulic system pressure filter removes 100% of all hydraulic fluid contamination particles larger than 15 microns. The filter assembly has: • • A filter element and bowl A Differential Pressure Indicator (DPI) The pressure filter is a non-bypass type. A shut-off device stops fluid flow through the filter when the filter bowl is removed. The DPI gives an indication of a clogged filter element. The No.3 hydraulic system pressure filter bowl is fully interchangeable with the case drain filter bowls of the No.1 and No.2 hydraulic system filter manifolds. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 60 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - No.3 HYDRAULIC SYSTEM PRESSURE FILTER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 61 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM ECOLOGY BOTTLE PURPOSE The No.3 hydraulic system ecology bottle collects hydraulic fluid released from the reservoir bleed/relief valve and leakage from the DCMP shaft seal. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 62 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM PRESSURE SWITCHES PURPOSE There are two pressure switches installed on the accumulator isolation valve which control operation of the DCMP. DESCRIPTION One of these pressure switches signals the DCMP to operate if system pressure drops to 2600 psi (17926 kPa). It also commands the DCMP off when system pressure reaches 3250 psi (22407 kPa). The other pressure switch causes the No.3 STBY HYD PUMP caution light to come on if: • • The system pressure falls to 900 psi (6205 kPa) The pump has been operating for longer than 60 seconds on the ground with at least one engine running An additional pressure switch is installed downstream of the isolation valve and causes the ELEVATOR PRESS caution light to come on if all three systems are supplying power to the elevator actuators. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 63 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM CONTROLS AND INDICATION The isolation valve is controlled by the HYD No.3 ISOL VLV switch-light on the HYDRAULIC CONTROL panel. The isolation valve is closed when the switch is in the NORM position. The isolation valve is commanded open in the air by either one or both of the hydraulic systems failing or when both engines have failed. The HYD No.3 Isolation Valve switch-light is blank when the isolation valve is in the NORM (closed) position. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 64 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC CONTROL PANEL DETAIL TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 65 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER NO.3 MAIN HYDRAULIC SYSTEM CONTROLS AND INDICATION CONTINUED If the system No.3 accumulator isolation valve fails open when both hydraulic systems are operating normally, all three hydraulic systems will be providing power to the elevator PCU. Since this results in excess elevator control authority, the ELEVATOR PRESS caution light will come on. The pressure switch is on the downstream side of the isolation valve. It senses pressure in series with the No.1 and No.2 hydraulic isolation valve inlet pressure switches. The No.3 STBY HYD PUMP caution light comes on when: • • The system pressure falls to 900 psi (6205 kPa) The pump has been operating for longer than 60 seconds on the ground TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 66 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC SYSTEM CAUTION INDICATIONS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 67 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM PURPOSE The alternate landing gear extension hydraulic system supplies hydraulic power to extend the main landing gear when main hydraulic power is not available. GENERAL DESCRIPTION The alternate landing-gear hand pump is located below an access door in the floor of the flight compartment. The hand pump must be used to extend the landing gear following isolation or loss of the No.2 hydraulic system. The pump draws hydraulic fluid from an auxiliary reservoir located in the nose compartment. Hydraulic fluid pressurizes the alternate extension actuators to extend the gear to the down-lock position. The system is controlled by the MLG alternate extension selector valve. The alternate extension selector valve is controlled by the alternate extension door. When the alternate extension door is closed, the alternate extension selector valve is open and ports the output of the hand-pump to the return line. When the alternate extension door is open, the alternate extension selector valve is closed, allowing the output of the hand-pump to flow to the alternate extension actuators. The selector valve also includes a relief valve to protect against over- pressurization. The alternate landing-gear extension system has these components: • • • Hydraulic Hand Pump MLG Alternate Extension Selector Valve Alternate Landing-Gear Extension Hydraulic Reservoir TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 68 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ALTERNATE LANDING GEAR EXTENSION HYDRAULIC SYSTEM (DOOR OPEN) TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 69 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM HYDRAULIC HAND PUMP PURPOSE The hand pump is used to lower the landing gear, following System 2 isolation. DESCRIPTION The hand pump is located below the flight compartment floor, adjacent to the copilot seat. The hand pump produces 0.75 in³/12.29 cm³ per stroke. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 70 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ALTERNATE LANDING-GEAR EXTENSION HYDRAULIC HAND PUMP TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 71 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM HYDRAULIC HAND PUMP HANDLE A hand pump handle is installed in the flight compartment on the bulkhead behind the copilot seat. The handle must be installed into the pump to operate it. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 72 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ALTERNATE LANDING-GEAR EXTENSION HYDRAULIC HAND PUMP HANDLE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 73 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM HYDRAULIC HAND PUMP VALVE - MLG ALTERNATE EXTENSION SELECTOR PURPOSE The pressure relief valve limits the pressure that may be applied to the alternate gear down actuators by relieving hand-pump pressure to return. The Main Landing Gear (MLG) alternate extension selector valve is located below the flight compartment floor adjacent to the copilot seat. DESCRIPTION The pressure relief valve limits the pressure that may be applied to the alternate gear down actuators by relieving hand-pump pressure to return. The Main Landing Gear (MLG) alternate extension selector valve is located below the flight compartment floor adjacent to the copilot seat. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 74 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - MLG ALTERNATE EXTENSION SELECTOR VALVE TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 75 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM HYDRAULIC HAND PUMP VALVE - MLG ALTERNATE EXTENSION SELECTOR CONTINUED DESCRIPTION The valve has: • • • • A 2-way, 2-position control valve A pressure relief valve A filtered inlet A filtered return port There is a pivoting link that attaches the selector valve to the alternate extension door. The selector valve moves from the normally open position to the closed position when the alternate extension door is opened. The valve cracking pressure is 3150 to 3850 psid (21718 to 26545 kPad). Full flow pressure is 3500 to 4300 psid (24132 to 29647 kPad ) at 0.50 gal/min (1.89 L/min). Reseat is at 2385 to 3465 psid (16444 to 23890 kPad ) with leakage of 5 cm³/min . TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 76 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - MLG ALTERNATE EXTENSION SELECTOR VALVE SCHEMATIC (DOOR CLOSED) TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 77 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER ALTERNATE LANDING GEAR EXTENSION SYSTEM HYDRAULIC HAND PUMP RESERVOIR PURPOSE This reservoir supplies the hydraulic fluid source for the alternate MLG extension hand pump. DESCRIPTION The alternate landing-gear extension hydraulic reservoir is located in the lower right nose compartment of the aircraft. The reservoir is made from aluminium and has a capacity of 1 US qt (0.95 L). The reservoir has a threaded, vented, removable lid which has three fittings installed. One fitting serves as a fill port, the second fitting is the vent and the third fitting is the outlet port to the hand pump. The lid also has a dipstick with minimum and maximum volume markings to allow filling of the reservoir to the correct fluid level. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 78 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - ALTERNATE LANDING-GEAR EXTENSION HYDRAULIC RESERVOIR TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 79 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER INDICATING PURPOSE The indicating system shows these indications in the flight compartment: • • • • Hydraulic pressures Hydraulic quantities System faults System operation status GENERAL DESCRIPTION Hydraulic system indications are shown on the: • • • • Multi-Function Displays (MFD) Caution and Warning panel HYDRAULIC CONTROL panel Fire Protection panel Information is sent to the Caution and Warning panel by temperature and pressure switches. Quantity and pressure transducers give inputs to the MFD. The indicating system has these components: • • • • • Hydraulic Pressure Transducers Hydraulic Quantity Transducers Hydraulic System Pressure Switch Temperature Switches 225°F/107°C and 275°F/135°C Hydraulic FSOV Switches TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 80 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER INDICATING QUANTITY TRANSDUCERS PURPOSE The quantity transducer sends an electrical signal to the flight data processing system which shows system fluid quantity on the MFD. DESCRIPTION Each hydraulic system reservoir has a quantity transducer to transmit the quantity of fluid in the reservoir to the flight compartment. The quantity transducers are installed on each of the three hydraulic system reservoirs. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 81 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER INDICATING PRESSURE TRANSDUCERS PURPOSE The pressure transducers send electrical signals to the flight data processing system which displays system fluid pressure on the MFD. DESCRIPTION There are two pressure transducers in the No.1 hydraulic system. One transducer sends system pressure data to the MFD. The other transducer sends Standby Power Unit (SPU) discharge pressure to the MFD. A pressure transducer installed in the No.2 hydraulic system sends system pressure data for display on the MFD. The No.3 hydraulic system has one pressure transducer installed in the accumulator isolation valve which sends system pressure data to the MFD. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 82 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC PRESSURE TRANSDUCER TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 83 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER accumulator isolation valve. INDICATING This pressure switch causes the ELEV PRESS caution light to come on if the No.1, No.2 and No.3 systems are all supplying power to the elevator actuators. NO.1 AND NO.2 HYDRAULIC SYSTEM PRESSURE SWITCHES PURPOSE These pressure switches monitor the pressure output from the pumps. DESCRIPTION Two pressure switches are installed on each of the No.1 and No.2 hydraulic system isolation valves. These pressure switches monitor hydraulic pressure at the inlet and outlet ports of the isolation valve. The No.1 or No.2 HYD ISOVLV caution light comes on when pressure is sensed at the inlet pressure switch, but not at the outlet. One EDP pressure switch is installed in the No.1 and No.2 hydraulic system filter manifolds. The No.1 or No.2 ENG HYD PUMP caution light comes on If the EDP fails. One pressure switch is installed in the No.2 hydraulic system, down steam from the PTU to give a pressure indication at the PTU discharge port. The PTU PBA ON light comes on if the pressure switch senses pressure. NO.3 HYDRAULIC SYSTEM PRESSURE SWITCHES PURPOSE The pressure switch sends a signal to the Caution and Warning panel. DESCRIPTION The No.3 hydraulic system has a pressure switch, installed downstream of the TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 84 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC PRESSURE SWITCH TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 85 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER INDICATING TEMPERATURE SWITCHES PURPOSE These switches monitor hydraulic fluid temperature. The No.1 and No.2 hydraulic system reservoirs each have a switch that monitors hydraulic fluid temperature. At 225°F/107°C, a HYD FLUID HOT caution light comes on. There is also a 275°F/135°C switch installed on the reservoir. If the temperature of the fluid in the reservoir reaches 275°F, this switch will close and in combination with the signal from the 225°F switch, will close the Firewall Shut Off Valve. There is a thermal switch in the SPU that turns on the No.1 STBY HYD PUMP HOT caution light if the pump windings are hot. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 86 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC TEMPERATURE SWITCH TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 87 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER INDICATING FIREWALL SHUT-OFF VALVE (FSOV) POSITION SWITCHES PURPOSE The FSOV position switches in the No.1 and No.2 hydraulic systems give FSOV position advisory indications on the Fire Protection Panel. DESCRIPTION The normally OPEN (green light) will go out and the CLOSED white light will come on when the FSOV is closed. TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 88 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - FSOV POSITION SWITCHES TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 89 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER • • INDICATING No.3 MAIN HYDRAULIC PRESSURE INDICATOR: CONTROLS AND INDICATIONS There are two Multi-Function Displays (MFD) in the flight compartment that show hydraulic system pressure and fluid quantity. There are three hydraulic system indications: • • • either the EDP or PTU Scale is marked every 1000 psi (6894 kPa) from 0 to 4 and indicated in white Reverts to white line when parameter no longer valid System No.1 and No.2 main pressure No.3 Standby main pressure No.1, No.2 and No.3 quantity indications • • • • Indicates pressure in No.3 hydraulic system Scale is marked every 1000 psi (6894 kPa) from 0 to 4 and indicated in white Reverts to white line when parameter no longer valid Digital values 0,2,4 are displayed on the right side of the No.3 scale No.1, 2, AND 3 HYDRAULIC QUANTITY INDICATORS: HYDRAULIC PRESSURES AND QUANTITY - ANALOGUE • • Indicate relative actual quantity available in the system reservoirs Quantities indicated in % of 100 where 100% represents the maximum quantity in each reservoir The copilot MFD shows data in analogue format during normal configuration. STANDBY HYDRAULIC PRESSURE INDICATOR: • • • Indicates pressure in No.1 hydraulic system available from the electrically operated standby pump Scale marked every 1000 psi (6894 kPa) from 0 to 4 and indicated in white Reverts to white line when parameter no longer valid SOURCE PARAMETER Pressure Transducers MFD Pressure Indications Quantity Transducers MFD Quantity Indications Pressure Switches Caution and Warning System Temperature Switches Caution and Warning System No.1 MAIN HYDRAULIC PRESSURE INDICATOR: • • • Indicates pressure in No.1 hydraulic system regardless of pressure source either the EDP or SPU Scale is marked every 1000 psi (6894 Pa) from 0 to 4 and indicated in white Reverts to white line when parameter no longer valid No.2 MAIN HYDRAULIC PRESSURE INDICATOR: • Indicates pressure in No.2 hydraulic system regardless of pressure source TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 90 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER - HYDRAULIC SYSTEM ANALOG INDICATIONS TO BE USED FOR MAINTENANCE TRAINING PURPOSES ONLY ATA 29 - HYDRAULIC POWER Issue 6 - January 2023 Page 91 of 104 BOMBARDIER DHC 8-400 (PWC PW150) HYDRAULIC POWER No.1, 2 AND 3 HYDRAULIC QUANTITY INDICATORS • • INDICATING HYDRAULIC PRESSURES AND QUANTITY Indicates relative actual quantity available in the system reservoirs Quantities indicated in % where 100 represents the maximum quantity in each reservoir Reservoir quantities are as follows: DIGITAL INDICATIONS The pilots MFD sho