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G3X/G3X Touch Installation Manual - Engine/Airframe Sensor Installation
Rev. AC
Page 23-11
23.2.3 Retrofit Engine Applications
When installing a G3X system in a completed aircraft with a typical piston engine, it is generally possible
to reuse a number of the existing engine sensors that may already be present. Consult section 28 for general
engine sensor wiring guidance that can be applied to existing sensors.
Table 23-10 Retrofit Engine Sensors
Sensor Type
Notes on Suitability for Reuse
RPM
Sensors that provide a digital output signal can be used without modification, if
calibration characteristics are known.
Do not connect G3X RPM inputs directly to magneto P-leads.
Manifold Pressure
Sensors that provide a voltage output can be used without modification, if
calibration characteristics are known.
Sensors that provide a resistance or current output may require replacement
with a supported sensor (e.g. 494-30004-01).
Oil Pressure
Sensors that provide a voltage output can be used without modification, if
calibration characteristics are known.
Sensors that provide a resistance or current output may require replacement
with a supported sensor (e.g. 494-30004-00).
Oil Temperature
Existing sensors are generally likely to require replacement with a supported
sensor (e.g. 494-70004-00).
Exhaust Gas
Temperature
Type K thermocouples can be used without modification. The GEA 24 J242
connector matches the pinout used by certain other engine monitoring
systems.
Cylinder Head
Temperature
Type J or K thermocouples can be used without modification. The GEA 24
J242 connector matches the pinout used by certain other engine monitoring
systems.
Turbine Inlet
Temperature
Type K thermocouples can be used without modification.
Fuel Pressure
Sensors that provide a voltage output can be used without modification, if
calibration characteristics are known.
Sensors that provide a resistance or current output may require replacement
with a supported sensor (e.g. 494-30004-02 or 494-30004-03).
Fuel Flow
Most sensors that provide a digital output signal can be used without
modification, if calibration characteristics are known.
Many existing installations use Floscan or Electronics International fuel flow
sensors that are directly supported by the G3X system.
Bus Current
Most shunt-type or Hall-effect sensors can be used without modification, if
calibration characteristics are known.
Fuel Quantity
Most sensors that provide a resistance, voltage, or frequency output can be
used without modification. New fuel quantity calibration will be performed
during G3X system installation.
For capacitive fuel quantity measurement, a third-party capacitance-to-
frequency or capacitance-to-voltage converter is required; the G3X system
does not support direct connection to capacitive fuel tank probes.