**ON A/C ALL
OIL TEMPERATURE INDICATING SYSTEM
1.
General
The oil temperature indicating system for each engine consists of an engine oil temperature
transmitter, connected to the temperature side of a dual pressure and temperature indicator
by electrical wiring. The transmitter is screwed into an adapter adjacent to the engine oil filter,
sensing oil temperature downstream from the fuel heater. The indicator is located on the
engine instrument panel in the flight compartment.
The systems are powered from the 28V dc essential buses, No. 1 engine oil temperature
indicating system from the left bus, protected by 5−ampere ENG 1, OIL TEMP IND circuit
breaker (M5). No. 2 engine system is powered from the right bus, protected by ENG 2, OIL
TEMP IND circuit breaker (K4) of the same value.
2.
Description and Operation
A.
Oil Temperature Transmitter
The engine oil temperature transmitter is a standard electrical resistance−type, in which
resistance varies in direct proportion to sensed oil temperature.
B.
Oil Pressure and Temperature Dual Indicator
The oil pressure and temperature dual indicator is marked ENG OIL and has two scales
and pointers, one scale marked PSI and the other degrees C.
On aircraft incorporating Mod 8/1050 the oil pressure/temperature dual indicator range
markings agree with revised oil pressure/temperature limits of the Pratt and Whitney
120/121 engine.
The degrees C scale is calibrated from −50 to +150 degrees C. with major graduations in
increments of 50 degrees C. and minor graduations in increments of 10 degrees C.
Pre Mod 8/1050 Indicator. The scale is provided with a max red radial at 115 degrees C,
a min red radial at −40 degrees C, a yellow arc from −40 degrees C to 0 degrees C and
99 to 115 degrees C, and a green arc 0 to 99 degrees C.
Mod 8/1050 Indicator. The scale is provided with a max red radial at 125 degrees C, a
min red radial at −40 degrees C, a yellow arc from −40 degrees C. to 45 degrees C. and
115 to 125 degrees C, and a green arc 45 to 115 degrees C.
The indicator provides a reading of oil temperature using a moving pointer against a
fixed dial marked degrees C.
Indicator lighting is white, powered by 5 V dc (refer to Chapter 33).
D
SERIES 100
AIRCRAFT MAINTENANCE MANUAL
MASTER
EFFECTIVITY: See Pageblock 79−34−00 page 1
79−34−00
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Dec 20/2004