Part #: 501-1228-04

Model: PS-835D






Emergency Power Supply

Part Number :
L3Harris Logo

  • A nominal 24Vdc Emergency Power System, which when combined with optional modules will supply 24Vdc, 115Vac 1O or 3O, 400Hz, and 5Vac, 400Hz or 24Vdc, and 5Vdc
  • The optional modules include: SI-100, SC-841, BC-815, or MTG-101A
  • The system may be tailored to provide power to an emergency attitude indicator and/or transceiver, lighting, etc
  • In the event that aircraft power fails, the batteries of the PS-835 take over the duties of supplying DC power to the plug-in module and any external loads without interruption
  • PS-835D has met STC requirements for installation on the Learjet 20/30 Series aircraft, and STC requirements for Learjet 50 Series aircraft
  • Contains sealed lead-acid batteries having a rating of 5.0 ampere-hours at the 10 hour rate
  • Consists of a chassis, two circuit card assemblies (CCAs), and assorted hardware
Dimensions: 7.626"H x 14.114"L x 2.282"W Weight: 13lbs
Input Voltage: +28-30Vdc Output Voltage: +24Vdc (nominal)
Altitude: 55000 ft Temperature: -55C to +70C
TSO: None exists    
Part Number Emergency Power Supply Description:
501-1228-04 See Details Above


Serial # 4946
Condition OH
Mods 1-6
Tag Date 05/28/24
Shop Southeast Aerospace Inc.
Warranty 6 Months
Serial # 12172
Condition OH
Mods 1-6
Tag Date 04/23/24
Shop Universal Aero Accessories
Warranty 6 Months
Serial # 2995
Condition OH
Mods 1-4,6
Tag Date 04/23/24
Shop Universal Aero Accessories
Warranty 6 Months
Serial # 82896
Condition OH
Mods 1-6
Tag Date 04/08/24
Shop Aries Aviation Corporation
Warranty 6 Months
Serial # 9300
Condition OH
Mods 1-6
Tag Date 11/15/23
Shop Universal Aero Accessories
Warranty 6 Months
- Emergency Power Supply

NSN: 6130-01-219-8285

Price Condition Status

Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact

Yes, the MD835 can directly replace the PS-835 in certain Part 23 aircraft installations. As of May 2023, there are no Part 25 STCs available for the MD835. Please contact us to inquire if your aircraft is approved for this upgrade replacement.

In relation to NE (New) parts, many OEMs change their prices and availability without any notice to dealers or the industry. Therefore, through the REQUEST or RFQ indication, we ask that customers contact us for the most accurate price and availability.

In relation to SV & OH parts, the used parts aftermarket in the aviation industry is not an infinite supply. It is a dynamic, constantly changing market that is significantly affected by and susceptible to highs and lows in supply and demand. Therefore, although we attempt to, at times, we are unable to predict the exact moment when an item may be available. Once again, through the REQUEST or RFQ indication on our website, we ask that customers contact us for the most current and accurate price and availability.

The Mid-Continent TS835 is a lighter weight alternative for the PS-835 power supplies. The TS835 weighs only 4.5 pounds while the PS-835 weighs 13 pounds. The TS835 has a battery life expectancy of 10 years. No rewiring or changing of the mounting rack is required when upgrading to the TS835 from the PS-835. Certification of the installation is not affected since TSO'd parts are being interchanged.

Negotiating the exchange price of a unit only limits the allowable repair cap for the core unit. Southeast Aerospace's exchange transactions are based on the return of economically repairable core unit. Once the core is received and evaluated, the core repair cost incurred by SEA cannot exceed 75% of the original exchange price. That is, it cannot cost SEA more than 75% of the original OH/SV exchange price collected from the customer. Therefore, when and if an SEA exchange price is discounted, there is a risk that additional charges may be assessed once the core is returned and evaluated.

According to L3 Service Letter SL-80 (Rev. W), the condition of the batteries should be checked every 3 to 6 months according to the Periodic Check procedure outlined in the bulletin. If the "Voltage Level 24VDC LED" does not illuminate while the 20VDC is illumined, then the unit is incapable of providing emergency power. The "Cell Isolation Test" must then be performed to identify if the unit requires repair or charging.