Ps-855b Maintenance Manual

is an aviation emergency power supply (EPS) unit manufactured by

(and previously JET or BFGoodrich) that provides backup power to attitude gyros and essential flight instruments. Proper maintenance is governed by the Component Maintenance Manual (CMM) TP-483 and technical service letters. Southeast Aerospace Inc. Maintenance Intervals and Requirements

To ensure airworthiness, the following checks are mandatory or highly recommended: Preflight Check (Recommended)

: A 5-second load test using the cockpit remote test switch or the "Push to Test" button on the unit's front panel. Periodic Check (Required every 3–6 Months)

: A formal verification of the battery condition following the preflight procedure. Capacity Testing (Required Annually)

: A full discharge test to determine if the battery cells can maintain 20 VDC for at least 48 minutes (specific to the PS-855B model). Southeast Aerospace Inc. Key Technical Specifications for Service

Maintenance personnel must adhere to these technical parameters during bench testing and charging: Input Power : 28 VDC, 15 Amps. Battery Output

: Nominal 24 to 28 VDC with an additional 5 VDC converter output (adjustable +2.5 to 5.5 VDC). Recharging

: Batteries reach 80% capacity within 1 hour; a full charge for optimum cell balancing requires 16 to 23 hours : Approximately 13.7 lbs (6.2 kg). Southeast Aerospace Inc. Support and Documentation

As of April 2023, production and publication services for these units have transitioned from Extant Aerospace Primary Manual CMM TP-483 (ATA 24-30-08) Service Literature Service Letter SL-170 provides detailed battery care and charging instructions. from the CMM or a list of authorized service centers for this unit? L3Harris PS-855B | SEAEROSPACE.COM ps-855b maintenance manual

The PS-855B emergency power supply, supported by Extant Aerospace, requires regular maintenance per Component Maintenance Manual (CMM) TP-483 to ensure operational reliability. Key procedures involve quarterly to semi-annual battery checks, capacitance testing, and adherence to Service Letter SL-170 for battery longevity. For the full maintenance manual, visit Scribd. PS-850/PS-855 Component Manual | PDF - Scribd

The PS-855B (P/N 501-1712-02) lead-acid emergency power supply, manufactured by L3Harris/Avionics Systems, requires regular maintenance guided by CMM TP-483 and Service Letter SL-170, including visual checks for outgassing and annual capacity tests. Essential procedures involve a 5-second push-to-test for capacity, a 7.0-ohm load test for 48 minutes, and specific 8 to 23-hour recharging requirements to ensure continued airworthiness. For detailed procedures, refer to the L3Harris CMM TP-483 documentation at seaerospace.com Southeast Aerospace Inc. L3Harris PS-855B | SEAEROSPACE.COM

The PS-855B (and its predecessor, the PS-850) is an aircraft Emergency Power Supply (EPS) manufactured by L3Harris (formerly JET or Goodrich). Maintenance procedures for this unit are strictly governed by specific technical publications. Primary Manuals and Documents

To "put together" the necessary paperwork for this unit, you typically need the following documents:

Maintenance Manual (TP-483): This is the primary reference. It provides detailed instructions for repair, testing, and troubleshooting.

Battery Maintenance Guide (SL-170): A critical supplement that focuses specifically on the battery cells. It covers storage, outgassing, and periodic capacity checks.

Installation and Operation Manual (24-30-07): Essential for initial setup and verifying the unit's interface with the aircraft's electrical system. Key Maintenance Requirements

The manual specifies a rigorous schedule to ensure the unit functions during an emergency:

Periodic Checks (Every 3 to 6 Months): Required to verify the physical condition of the batteries and their basic charge status. is an aviation emergency power supply (EPS) unit

Annual Capacity Checks: A mandatory test to ensure the battery can still provide the required power for the specified duration.

Charging Procedures: Instructions for recharging the unit using recommended equipment like test panels and load resistors.

Storage Guidelines: If the unit is removed for storage, the battery must be maintained according to specific outgassing and temperature protocols to prevent degradation. Where to Source These Documents You can obtain official copies from these sources:

L3Harris Avionics Support: The current manufacturer and source for authorized service literature and technical updates.

Scribd (TP-483 Archive): Hosts digital versions of the maintenance manual and component manuals.

Essco Aircraft: Sells printed or digital copies of the B.F. Goodrich version (TP-483).

Do you need specific wiring diagrams or a list of required test equipment for the annual capacity check? TP 483 - PS 850 PS 855 - Rev.B | PDF | Electricity - Scribd

Grand Rapids, MI 49512-9704, USA July 30, 2014. [Link] Foreword. This manual provides information intended for use by persons who, PS-850/PS-855 Component Manual | PDF - Scribd PS-850/PS-855 Component Manual | PDF. 4K views230 pages. PS-850/855 Battery Maintenance Guide | PDF - Scribd

This is a helpful guide for locating and using the PS-855B Maintenance Manual. Chapter 9: Digital Revisions – When the Manual

Important Note: The "PS-855B" is not a widely recognized global model number for common consumer electronics (like a printer, TV, or laptop). It is most likely a specific industrial controller, power supply, medical device component, or an internal part number for a larger machine (e.g., from Yaskawa, Omron, Siemens, or a PCB assembly).

Because of this, a generic manual does not exist. Follow this guide to find the correct manual for your specific device.

Chapter 9: Digital Revisions – When the Manual Doesn’t Match Your Board

A significant frustration is discovering that your physical PS-855B unit is a revision 4 while the available manual is for revision 1. What then?

1. Compare board silkscreen: Look for a board number (e.g., PS-855B-MAIN-03). Search for that exact number.
2. Check for service bulletins: The manufacturer may have released "amendments" to the manual. These are often one-page PDFs addressing component changes (e.g., "Change R47 from 1k to 1.2k").
3. Reverse-engineer small sections: If you only need to replace one capacitor, trace the circuit. Use a multimeter in continuity mode to map out the power rails.

Pro tip: Join a PS-855B user group on Groups.io or Reddit. Other owners often share revision-specific addendums.

Chapter 8: Where to Download or Purchase the PS-855B Maintenance Manual

If you cannot find the manual bundled with your unit, here are reliable sources (as of this article’s publication):

Chapter 4: Common Failures and How the Manual Solves Them

Based on service logs from repair shops, the PS-855B exhibits several age-related failures. The maintenance manual provides specific remedies.

2.3 What If No Official Manual Exists?

If the original manual is lost or unavailable, specialized repair databases like ElektroTanya, EServiceInfo, or Badcaps.net forums often host user-uploaded technical manuals for the PS-855B.

Warning: Avoid “free PDF” sites that require credit card registration. Authentic maintenance manuals are usually free or sold by authorized distributors for $15–$50.

Mistake #2: Using Standard Capacitors Instead of Low-ESR

The manual’s parts list specifies low-impedance or low-ESR capacitors (e.g., Rubycon ZLH, Nichicon HE). Using general-purpose caps leads to overheating and short life.