C I R R U S CONTROLLING DESCRIPTION

Transcription

1 CONTROLLING 1. DESCRIPTION Serials & subs: An electric two-speed fuel pump provides boost (low speed) and prime (high speed) for the engine. A console mounted rocker switch located on the center console provides control for the electric fuel pump. The prime position is momentary. Boost is a non-momentary on position. Serials 22T-0001 & subs: An electric two-speed fuel pump provides boost (low speed) and high boost/ prime (high speed) for the engine. A console mounted rocker switch located on the center console provides control for the electric fuel pump. The boost and high boost/prime are non-momentary on positions. Serials thru before SB : A fuel pressure based system is used to control boost pump operation. Both positions of the pump normally operate on the low-speed setting. For engine priming, a pressure actuated switch located on the fuel injection distribution manifold allows the pump to run on high speed when fuel system pressure is below 3 PSI. This allows rapid priming of the fuel system for starting. Once the fuel system is primed, the electric pump is switched to the low-speed setting by the pressure switch. The boost position operates the electric pump at the low-speed setting only, regardless of fuel system pressure. The boost pump operates on 28 VDC supplied through the 5-amp FUEL PUMP circuit breaker on Main Bus 2. Serials thru , thru after SB : An oil pressure based system is used to control boost pump operation. The oil pressure/temperature gage provides a signal to the starting circuit to generate a ground for the oil annunciator and the fuel system. This system allows the fuel pump to run at the prime (high speed) when the engine oil pressure is less than 10 PSI. Whenever the engine oil pressure exceeds 10 PSI, pressing the prime switch will have no effect. The boost position operates the electric pump at the low-speed, regardless of oil pressure. The boost pump operates on 28 VDC supplied through the 5-amp FUEL PUMP circuit breaker on Main Bus 2. Serials thru , & subs w/o Perspective Avionics: An oil pressure based system is used to control boost pump operation. The oil pressure sensor provides a signal to the data acquisition unit to generate a ground for the oil annunciator and the fuel system. This system allows the fuel pump to run at the prime (high speed) when the engine oil pressure is less than 10 PSI. Whenever the engine oil pressure exceeds 10 PSI, pressing the prime switch will have no effect. The boost position operates the electric pump at the low-speed, regardless of oil pressure. The boost pump operates on 28 VDC supplied through the 5-amp FUEL PUMP circuit breaker on Main Bus 2. Serials & subs w/ Perspective Avionics: An oil pressure based system is used to control boost pump operation. The oil pressure sensor provides a signal to the GEA 71 engine airframe unit to generate a ground for fuel pump inhibition. This system allows the fuel pump to run at the prime (high speed) when the engine oil pressure is less than 10 PSI. Whenever the engine oil pressure exceeds 10 PSI, pressing the prime switch will have no effect. The boost position operates the electric pump at the low-speed, regardless of oil pressure. The boost pump operates on 28 VDC supplied through the 5-amp FUEL PUMP circuit breaker on Main Bus 2. Serials 22T-0001 & subs: An manifold pressure/rpm based system is used to control boost pump operation. The manifold pressure sensor provides a signal to the GEA 71 engine airframe unit to generate fuel pump inhibition. To prevent over-priming during low power settings, the system uses a lockout relay that only allows HIGH BOOST/PRIME fuel pump operation when manifold pressure is greater than 24 inhg. or - to facilitate engine starting - when engine speed is less than 500 RPM. Whenever the engine parameters fall outside these specifications, pressing HIGH BOOST/PRIME will turn the pump on in low-speed mode. Selecting BOOST energizes the fuel pump in low-speed mode regardless of engine speed or manifold pressure to deliver a continuous 4-6 psi boost to the fuel flow for vapor suppression in a hot fuel condition. The boost pump operates on 28 VDC supplied through the 5-amp FUEL PUMP circuit breaker on Main Bus 2. All Page 1 01 May 2012

2 2. MAINTENANCE PRACTICES A. Fuel Pressure Switch - Serials thru before SB (See Figure 1) (1) Removal - Fuel Pressure Switch (a) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (b) Remove engine cowling. (Refer to 71-10) (c) At fuel injector manifold, locate fuel pressure switch and associated wire leads. (d) Disconnect adel clamps securing bundled wire harnesses to engine. (e) Remove cable ties and plastic sheath bundling wire harnesses. (f) Disconnect fuel pressure switch jack J104 located on aft RH side of engine baffling. (g) Remove adel clamp securing fuel pressure switch to engine standoff. (h) Remove fuel pressure switch from injector manifold fitting, gently de-bundle fuel pressure switch wire leads from bundled harnesses, and remove fuel pressure switch from airplane. (2) Installation - Fuel Pressure Switch (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Fuel Fitting Grease MIL-G Any Source Lubrication. (b) Apply thin coat of grease to injector manifold fitting. (c) Install fuel pressure switch to fitting. (d) Install adel clamp securing fuel pressure switch to engine standoff. (e) Route switch leads in with bundled harnesses, ensure plastic sheath covers all wires, and close with cable ties. (f) Connect fuel pressure switch jack J104 to associated plug. (g) Install adel clamps securing harness bundle to engine. (h) Install engine cowling. (Refer to 71-10) Page 2 01 Feb 2013 Serials thru before SB

3 B. Starting Circuit Assembly - Serials , , , after SB (See Figure 1) (1) Removal - Starting Circuit Assembly (a) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (b) Remove glareshield. (Refer to 25-10) (c) Disconnect and disassemble firewall ground connector J110. (d) Disconnect pin 18 and wire IESC from connector J110. (e) Disconnect starting circuit assembly from oil pressure/temperature gage and connector P650. Remove starting circuit assembly from airplane. (2) Installation - Starting Circuit Assembly (a) Install pin 18 and wire IESC to connector J110. (b) Reassemble connector J110 and install to connector P110. (c) Connect starting circuit assembly to oil pressure/temperature gage and connector P650. (d) Install glareshield. (Refer to 25-10) Serials , , , after SB Page 3 15 Jun 2010

4 FUEL MANIFOLD VALVE 2 Serials thru before SB OIL PRESSURE/TEMPERATURE GAGE P650 1 P110 FIREWALL LEGEND 1. Starting Circuit Assembly 2. Fuel Pressure Switch Serials thru after SB , thru , thru , thru SR22_MM73_1556A Figure 1 Fuel Pressure Switch and Starting Circuit Assembly Installation - Serials thru Page 4 15 Jun 2010 Serials thru

5 C. Fuel Pump Setup - Serials 22T-0001 & subs (1) Functional Test - Fuel Pump Setup (See Figure 2), (See Figure 3) (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Fuel Pressure Gauge or Porta-Test Any Source Aero-Test, Inc. Romulus, MI Set unmetered pressure. (b) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (c) Remove engine cowling. (Refer to 71-10) (d) At LH side of throttle body assembly, turn idle speed stop screw counter-clockwise two complete turns. Note: When idle mixtures and low-unmetered fuel pressures are changed, engine idle is affected by the change in mixture ratios. During following fuel system adjustment, IDLE RPM is controlled manually using cockpit throttle control. (e) (f) (g) (h) (i) (j) (k) (l) At RH side of throttle body assembly, remove and retain cap from unmetered fuel pressure port. Connect pressure gauge or Porta-Test to unmetered fuel pressure port using length of hose providing proper clearance from engine cowling and propeller arc. If using Porta-Test, refer to manufacturer s approved Instructions for Continued Airworthiness to perform optional Manifold Pressure and Upper Deck Pressure hose connections. Position throttle control in FULL OPEN position and mixture control to FULL RICH. Set BAT 1 switch to ON positions. Operate boost pump. Loosen test connection at unmetered pressure gauge or Porta-Test to bleed line of any air. Tighten connection after bleeding. Prime engine in accordance with Pilot s Operating Handbook. CAUTION: Do not run prime pump dry more than 15 seconds. If pump runs for more than 15 seconds before switching to low speed, ensure fuel selector valve is in ON position. Serials 22T-0001 & subs (m) Start engine in accordance with Pilot s Operating Handbook. (n) Bring oil temperature into normal, green operating range of ºF (77-82 ºC). (o) Verify oil pressure is within psi. (p) At full power, ensure that manifold pressure is within specifications. (See Figure 3) (q) At 600 RPM and boost pump off, slowly move mixture control toward IDLE CUT-OFF position. (r) At RH side of throttle body assembly, locate idle mixture screw recessed within forwardfacing boss of fuel-metering cover and set air-fuel mixture to obtain rise of RPM. 1 Turn idle mixture screw clockwise to lean air-fuel mixture as required. 2 Turn idle mixture screw counter-clockwise to enrich air-fuel mixture as required. (s) If RPM rise is not within specifications: 1 Advance throttle to RPM for 15 seconds after each adjustment to clear engine. Page 5 31 May 2011

6 2 Retard throttle to 600 RPM and repeat air-fuel mixture adjustment. 3 Record maximum RPM rise. (t) At 600 RPM, set unmetered fuel pressure to psi. 1 At aft centerline of fuel pump, loosen lock nut on idle low-pressure relief valve bolt. 2 Turn idle low-pressure relief valve bolt clockwise to increase fuel pressure as required. 3 Turn idle low-pressure relief valve bolt counter-clockwise to decrease fuel pressure as required. (u) Advance throttle to 2500 RPM (full power), and turn boost pump on to BOOST position. (v) At fuel pump, set fuel flow within specifications. (See Figure 3) 1 Loosen lock nut on high fuel flow aneroid screw. 2 Turn high fuel flow aneroid screw clockwise to decrease fuel flow as required. 3 Turn high fuel flow aneroid screw counter-clockwise to increase fuel flow as required. CAUTION: Use care while tightening lock nut to avoid stripping threads. (w) 4 Tighten lock nut on high fuel flow aneroid screw. Verify unmetered fuel pressure is psi. CAUTION: If unmetered pressure is outside of limits, but manifold pressure and fuel flow both fall within specifications, then fuel obstruction (high pressure only), fuel flow, manifold pressure, or fuel pressure gauge error is likely and should be corrected prior to completing fuel setup. (x) (y) Operate engine for minimum of 5 minutes at RPM after FULL power operation prior to shut down. Bring engine back to 600 RPM and verify unmetered pressure remains psi. CAUTION: Use care while tightening lock nut to avoid stripping threads. (z) At fuel pump, tighten lock nut on idle low-pressure relief valve bolt. (aa) At LH side of throttle body assembly, adjust idle speed stop screw to set idle speed to 700 ±25 RPM. 1 Turn idle speed stop screw clockwise to increase speed as required. 2 Turn idle speed stop screw counter-clockwise to decrease speed as required. (ab) Record following values: Unmetered pressure at 600 and 2500 RPM MAP Fuel flow at 2500 RPM Idle RPM rise Page 6 31 May 2011 (ac) At RH side of throttle body assembly, disconnect pressure gauge or Porta-Test from unmetered fuel pressure port. (ad) Reinstall cap to unmetered fuel pressure port. (ae) If using Porta-Test, disconnect any optional Porta-Test hose connections in accordance with manufacturer s approved Instructions for Continued Airworthiness. (af) Install engine cowling. (Refer to 71-10) Serials 22T-0001 & subs

7 THROTTLE BODY ASSEMBLY IDLE SPEED STOP SCREW IDLE MIXTURE SCREW UNMETERED FUEL PRESSURE PORT TO PRESSURE GAUGE OR PORTA-TEST OIL FILTER HIGH FUEL FLOW ANEROID SCREW FUEL PUMP IDLE LOW-PRESSURE RELIEF VALVE BOLT NOTE At LH side of throttle body assembly, turn idle speed stop screw counter-clockwise two complete turns. Connect pressure gauge or Porta-Test to unmetered fuel pressure port using length of hose providing proper clearance from engine cowling and propeller arc. At RH side of throttle body assembly, locate idle mixture adjustment screw recessed within forward-facing boss of fuel-metering cover and set air-fuel mixture to obtain rise of RPM. At 600 RPM, adjust idle low-pressure relief valve bolt to set unmetered fuel pressure to psi. At fuel pump, adjust high fuel flow aneroid screw to set fuel flow within specifications. SR22_MM73_3433 Serials 22T-0001 & subs Figure 2 Fuel Pump Setup - Serials 22T-0001 & subs Page 7 31 May 2011

8 Fuel Flow (GPH) Manifold Pressure ("Hg) Page 8 31 May 2011 Figure 3 Manifold Pressure and Fuel Flow Range at 2500 RPM - Serials 22T-0001 & subs Serials 22T-0001 & subs SR22_FM73_3432