Ps-855b Maintenance Manual _hot_ May 2026

With no external power applied, press and hold the button for 5 seconds.

The is a self-contained emergency power supply designed primarily for aircraft to provide critical standby power to attitude gyros and essential flight instruments in the event of a total electrical failure. Manufactured by L-3 Communications (now L3Harris) and supported by Extant Aerospace , this unit relies on sealed lead-acid batteries and requires strict adherence to its Component Maintenance Manual (CMM TP-483) to ensure flight safety. Core Maintenance Requirements

According to the PS-855B documentation on Scribd , technical personnel should follow these specific steps: ps-855b maintenance manual

Batteries must be left in a discharged state, as this causes permanent damage.

If the stays illuminated for the full 5 seconds, capacity is above 50%. With no external power applied, press and hold

A condition check must be performed every quarter or half-year to verify the unit's operational status. This is similar to a "Preflight Check" and ensures the unit is ready for emergency deployment.

Maintenance for the PS-855B is governed by , which outlines the mandatory periodic checks and testing intervals. This is similar to a "Preflight Check" and

The unit can reach 50% capacity within one hour at 25°C under normal flight conditions.