Specifications

Information Manual 7-63
Cirrus Design Section 7
SR20 Airplane Description
Boost Pump Switch
Boost pump operation and engine prime is controlled through the Fuel
Pump BOOST-PRIME switch located adjacent to the fuel selector
valve. The PRIME position is momentary and the BOOST position is
selectable. A two-speed prime allows the fuel pressure to rapidly
achieve proper starting pressure.
An oil pressure based system is used to control boost pump operation.
The oil pressure/oil temperature sensor provides a signal to the
starting circuit/DAU to generate a ground for the oil annunciator and
the fuel system. This system allows the fuel pump to run at high speed
(PRIME) when the engine oil pressure is less than 10 PSI. Whenever
the engine oil pressure exceeds 10 PSI, pressing PRIME will have no
effect. Selecting BOOST energizes the boost pump in low-speed
mode regardless of oil 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 7.5-amp
FUEL PUMP circuit breaker on Main Bus 2.
March 2010