The A320 ECAM APU page with its parameters is described in the image above as follows:
- 1: AVAIL
- 2: APU bleed air valve position
- 3: APU bleed air pressure
- 4: APU GEN line contactor indication
- 5: APU GEN parameters
- 6: FUEL LO PR
- 7: FLAP OPEN
- 8: APU N
- 9: APU EGT
- 10: LOW OIL LEVEL
Reference Aircraft: A320neo/LEAP-1A26
- Displayed in green when APU N is above 95 %.
2. APU bleed air valve position
- Inline-Green : The APU bleed air valve is not closed.
- Crossline-Green : The APU bleed air valve is closed.
- Crossline-Amber : The APU bleed air valve is closed and the APU bleed is ON.
- XX-Amber : The APU bleed air valve status information is not available, or the APU BLEED pb status is not available.
3. APU bleed air pressure
- This box displays the relative bleed air pressure in green.
- It shows an amber XX when the ADIRS1 or the ADIRS2 is not available or selected OFF or the data from the ECB are invalid or not transmitted.
4. APU GEN line contactor indication
- Displayed in green when the APU GEN line contactor is closed.
5. APU GEN parameters
- Identical to the APU GEN parameters on the ELEC page.
6. FUEL LO PR
- Displayed in amber if APU fuel pressure gets low.
7. FLAP OPEN
- The FLAP OPEN message is displayed in steady green, when the APU air intake flap is fully opened (signal received by the SDAC) and the APU master pushbutton switch is on.
- The FLAP OPEN message is displayed in green and pulsing, when the APU air intake flap is not fully closed and the APU master pushbutton switch is off (for at least 3 min.).
8. APU N
- Displays APU speed in green.
- Becomes amber when N ≥ 102 %.
- Becomes red when N ≥ 107 %.
9. APU EGT
- Displays APU EGT in green.
- Becomes amber when EGT ≥ EGT MAX -33 °C.
- Becomes red when EGT ≥ EGT MAX (automatic shutdown begins).
- Note: ECB calculates EGT MAX and transmits it to the ECAM. It is a function of N during start, and a function of ambient temperature when the APU is running.
- Maximum EGT during start: 1120 °C (above 35 000 ft).
- Maximum EGT during start: 1 090 °C (below 35 000 ft).
- Maximum EGT with APU running: 675 °C.
10. LOW OIL LEVEL
- The message LOW OIL LEVEL is displayed in green and pulsing, when an APU oil low level signal is received from the ECB via the SDAC.