DOC AIRBUS | AMM A320FLOW OIL PRESSURE AND HIGH OIL TEMPERATURE WARNING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The low oil pressure and high oil-temperature warning-system together with the ECB 59KD monitor the APU oil pressure and the oil temperature. They also monitor the temperature of the APU generator scavenge oil. The system protects the APU against low oil pressure and high oil temperature.
When the ECB 59KD receives the low oil pressure or a high oil-temperature signal, it starts the APU automatic shutdown-sequence (Ref. AMM D/O 49-61-00-00).
** ON A/C NOT FOR ALL The low oil pressure and high oil-temperature warning-system together with the ECB 59KD monitor the APU oil pressure and the oil temperature. They also monitor the temperature of the APU generator scavenge oil. The system protects the APU against low oil pressure and high oil temperature.
When the ECB 59KD receives the low oil pressure or a high oil-temperature signal, it starts the APU automatic shutdown-sequence (Ref. AMM D/O 49-61-00-00).
2. Component Location
** ON A/C NOT FOR ALL 
LOP and HOT Warnings - Componemt Location| FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 8084KM | SENSOR - TEMPERATURE, HIGH OIL | 315AL | 315 | 49-91-51 | |
| 8091KM | SWITCH-LOP | 316AR | 316 | 49-94-14 | |
3. System Description
A. Low Oil and High Oil Pressure Warning
(1) The low oil pressure and high oil-temperature warning-system has the subsequent primary components:
The HOT SNSR is installed downstream of the oil cooler on the lower rear face of the gearbox. It measures the oil temperature at the oil cooler outlet. The ECB receives the temperature signal from the HOT SNSR. If the oil temperature is too high the ECB starts the automatic APU shutdown sequence.
- an Oil-Pressure Switch (referred as Low-Oil Pressure Switch LOP SW),
- an Oil-Sump Temperature Sensor (referred as High-Oil Temperature sensor HOT SNSR).
The HOT SNSR is installed downstream of the oil cooler on the lower rear face of the gearbox. It measures the oil temperature at the oil cooler outlet. The ECB receives the temperature signal from the HOT SNSR. If the oil temperature is too high the ECB starts the automatic APU shutdown sequence.
4. Interface
The Low Oil Pressure and High Oil Temperature Warning system has interface with:
** ON A/C NOT FOR ALL The Low Oil Pressure and High Oil Temperature Warning system has interface with:
- the APU Control and Monitoring System (Ref. AMM D/O 49-61-00-00),
- the Storage and Distribution System (Ref. AMM D/O 49-91-00-00).
5. Operation/Control and Indicating
The HOT SNSR measures the temperature of the oil downstream of the oil cooler. The ECB 59KD receives the temperature signal and thus it monitors the APU oil temperature. It starts the APU automatic shutdown sequence if the oil temperature is more than the limit (Ref. AMM D/O 49-61-00-00).
The LOP SW monitors the pressure downstream of the oil pressure filter. It transmits a low oil-pressure signal to the ECB 59KD when the oil pressure decreases below the limit (Ref. AMM D/O 49-61-00-00). Then the ECB starts the APU automatic shutdown sequence.
The HOT SNSR measures the temperature of the oil downstream of the oil cooler. The ECB 59KD receives the temperature signal and thus it monitors the APU oil temperature. It starts the APU automatic shutdown sequence if the oil temperature is more than the limit (Ref. AMM D/O 49-61-00-00).
The LOP SW monitors the pressure downstream of the oil pressure filter. It transmits a low oil-pressure signal to the ECB 59KD when the oil pressure decreases below the limit (Ref. AMM D/O 49-61-00-00). Then the ECB starts the APU automatic shutdown sequence.