# SDR 99UAL900127

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 21, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N441UA](https://openairdocs.org/aircraft/N441UA), registered now
- Make and model: Airbus A320-232
- Registry model: [Airbus A320-232](https://openairdocs.org/model/airbus-a320-232) (OpenAirDocs)
- Aircraft serial: 751
- Engine: Iae V2527A5
- System (JASC): [3350 · Emergency Lighting](https://openairdocs.org/jasc/3350)
- Part: Power Supply
- Part number: 321454
- Condition: Inop
- Location: Cabin
- Component: Diehl Gmbh &, 321430
- Stage of operation: IN
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99UAL900127

## Discrepancy

EMERGENCY LIGHT TEST FAILS WITH EPSU INT LOAD R MESSAGE. *S/D* INTERNAL LOAD FAULT WAS DETECTED AT THE EMERGENCY POWER SUPPLY UNIT (12WL).  THE EMERGENCY POWER SUPPLY UNIT AND ITS BATTERY WERE THEN REPLACED.

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