DOC AIRBUS | AMM A320FOIL TEMPERATURE INDICATING SYSTEM - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. Oil Temperature Sensors
The oil temperature is measured at two engine locations:
The oil temperature is measured at two engine locations:
- One for the engine condition monitoring,
- One for the cooling system control of the Integrated Drive Generator.
A. Oil Temperature Sensor for the Engine Condition Monitoring (signal to EIU) 4004EN
Oil Temperature Sensor - Location (Engine Condition Monitoring)- The oil temperature sensor is located on the oil pressure filter downstream of the pressure pump.
- The oil temperature is sensed by a single element. The unit consists of a sealed, wire-wound resistance element. This element causes a linear change in the Direct Current (DC) resistance when exposed to a temperature change.
- Temperature measurement range: -50 deg.C (-58.00 deg.F) to 200 deg.C (392.00 deg.F).
B. Engine Oil Temperature Sensor for the IDG Cooling System Control
(1) General
The oil temperature sensor (ECU) is located above the oil tank and on the oil supply tube (to the forward bearing sump) which runs just at 9 O'clock, aft looking forward.
The sensor is a dual type thermocouple (Chromel/alumel).
The oil temperature sensor (ECU) is located above the oil tank and on the oil supply tube (to the forward bearing sump) which runs just at 9 O'clock, aft looking forward.
The sensor is a dual type thermocouple (Chromel/alumel).
(2) Description
The oil temperature sensor is composed of the following:
The oil temperature sensor is composed of the following:
- A metal body including:
A fixed connector.
A shoulder which ensures seating of the thightening nut.
A cylindrical part provided with a groove which accommodates a seal for sensor thightness.
A cylindrical boss in which are inserted the 2 hot junctions of the thermocouples. - A nut to secure the sensor on the oil tube.
(3) Operation
Each thermocouple is inserted in the sensor. It generates an electromotive force proportional to the surrounding temperature (oil temperature) of the hot junctions. Both signals (channel A and B) are routed to the Engine Control Unit (ECU).
Temperature range: from -70 deg.C to 300 deg.C
Each thermocouple is inserted in the sensor. It generates an electromotive force proportional to the surrounding temperature (oil temperature) of the hot junctions. Both signals (channel A and B) are routed to the Engine Control Unit (ECU).
Temperature range: from -70 deg.C to 300 deg.C
C. Oil Temperature Indicating
- Only the oil temperature for engine condition monitoring is indicating in the cockpit.
- The analog signal from the temperature sensor is transmitted to the Engine Interface Unit (EIU).
The EIU transforms this signal into a digital signal. - This digital signal is then transmitted to the lower display unit of the ECAM system through the Flight Warning Computer (FWC) and the Display Management Computer (DMC).
- Advisory level : the oil temperature indication flashes green when the temperature is higher than 140 deg.C (284 deg.F).
The indication becomes amber and the MASTER CAUT light comes on when the oil temperature is higher than 155 deg.C (311 deg.F) or higher than 140 deg.C (284 deg.F) during more than 15 minutes. - The EIU looks at both the outputs from sensor 4004 EN and from output of the ECU dedicated oil temperature sensor used for the control of the fuel return valve in the IDG oil cooling logic. This sensor is hardwired to ECU via J13 harness. This sensor could be used based on the fact that due to the engine and IDG oil cooling system design, there is a close relation ship between the engine and the IDG oil variation.1 deg.c change in the IDG oil correspond to 1 deg.c change in the engine oil while both oil temperature levels are different. The EIU performs a permanent cross check between sensor 4004 EN and the ECU dedicated sensor and flags sensor 4004 EN at fault if both outputs disagree. This disagree will trigger failure message "ECU 4000 KS OR OIL TEMP SENSOR 4004 EN". The EIU will not trigger this fault if the ECU dedicated oil temperature sensor is faulty as the cross check will nolonger take place and the EIU cross check logic is degraded. An ECU dedicated oil temperature sensor is announced by failure message "EOT SNSR, J13, ECU". The EIU receives the ECU dedicated oil temperature sensor input on label 316 from the ECU on the ARINC bus (See ASM 73-25/10). In addition, if the oil temp sensor 4004 EN indicates a temperature lower than -60 deg.c or greater than 210 deg.c, failure message"OIL TEMP SENSOR 4004 EN" will be set.