Ps-855b Maintenance Manual -
Emergency Power Supply (EPS) unit manufactured by (formerly J.E.T. / BFGoodrich) and now supported by Extant Aerospace
- Using a calibrated reference gauge, slowly increase system pressure.
- Verify the electrical contact changes state (NO closes or NC opens) at the setpoint.
- Verify the switch resets when pressure drops below the deadband threshold.
Automatic Charge Management
: Instructions on how the unit automatically maintains full charge during normal flight, reaching 50% capacity within just one hour of operation. ps-855b maintenance manual
Without the manual's schematic, this repair is guesswork. With it, it is systematic. Emergency Power Supply (EPS) unit manufactured by (formerly
- No output on one rail (e.g., missing -12V)
- Intermittent shutdowns under load
- Audible high-pitch whine from the transformer
- Burnt smell near the input filtering capacitors
The manual’s flowchart distinguishes:
Load Resistor:
A 7.0-ohm resistor (rated for at least 150 watts) is necessary to simulate operational load during capacity checks. Procurement and Service Literature PS-850/PS-855 Component Manual | PDF - Scribd Using a calibrated reference gauge, slowly increase system
- The Art of Electronics (for general power supply theory)
- ESR Meter Guide (for capacitor testing specific to PS-855B)
- Contact the author: If you have a specific PS-855B maintenance manual revision not listed in public archives, please consider scanning and contributing to the community.