Aircraft Electrical Power (Part 2)

Aircraft Electrical Power

•Batteries installation and operation
•Electronics emergency equipment requirements
•Cabin entertainment equipment 

Batteries installation and operation

Location Requirements

1. Accessibility for Battery Maintenance and Removal 
2. Protection from Engine Heat
3. Protection from Mechanical damage
4. Passenger Protection
5. Air frame Protection 

1. Accessibility for Battery Maintenance and Removal -

Install and locate the battery so that it can be readily removed and re-installed. The electrolyte level of the battery needs frequent checking.

2. Protection from Engine Heat -

The installation should protect the battery from extreme engine heat, which would be detrimental to the battery's service life and reliability. When locating the battery within the engine compartment, choose a location that will not interfere with the flow of engine cooling air.

3. Protection from Mechanical damage -

Vibration and other shock loads are a major cause of short battery life. Whenever possible install the battery in a manner or location that will minimize damage from airframe vibration and prevent accidental damage by passengers or cargo.

4. Passenger Protection -

Enclose the battery in a box or other suitable structure to protect passengers from any fumes or electrolyte that may be spilled as a result of battery overheating, minor crash, inverted flight, and/or rapid decompression.

5. Airframe Protection -                     

• Protect the airframe structure and fluid lines by applying asphaltic or rubber-base paint to the areas adjacent to and below the battery or battery box.
• Apply paralketone, heavy grease, or other comparable protective coating to control cables in the vicinity of the battery or battery box.
• Damage to adjacent fabric covering and electrical equipment can be minimized by providing a battery sump jar containing a neutralizing agent, properly locating battery drains and vent discharge lines, and adequately venting the battery compartment.

Image Courtesy : skygeek.com
Ni-Cd Battery

Image Courtesy: Wikipedia
Aircraft Battery Cell

Nickel Cadmium (Ni-Cd) Battery             Ni-Cd cells contain interleaved anodes associated by means of inward current gatherers to terminals that go through the cell cover. Between the anodes, a non-woven polyamide felt separator keeps the basic electrolyte in contact with the dynamic surface. It avoids short circuits while permitting current course through the electrolyte. The separator framework incorporates an oxygen obstruction made of natural or miniaturized scale permeable manufactured material. Amid cheat, this boundary limits oxygen recombination to guarantee low and stable cheat current. 

The cathode get together is housed in an unbending plastic compartment that enables cells to be fitted next to each other in a battery case. Every cell is furnished with a low weight vent valve that can be expelled to permit water expansion. The vent permits gas created in ordinary operation to be discharged while keeping electrolyte from getting away and contaminants from entering. Ni-Cd airplane batteries normally comprise of a metal box containing 20 singular arrangement cells associated utilizing unbending, profoundly conductive, nickel-plated copper cell connects that are secured by nickel-plated copper nuts on the cell terminals.

Lead-Acid Battery

Lead-Acid batteries utilized as a part of aircraft are like car batteries. The cells of a battery are associated in arrangement. Every cell contains positive plates of lead peroxide, negative plates of springy lead, and electrolyte (sulfuric corrosive and water). In releasing, the concoction vitality put away in the battery is changed to electrical vitality; in charging, the electrical vitality provided to the battery is changed to compound vitality and put away. It is conceivable to charge a capacity battery ordinarily before it break down forever.

Lead-Acid Cell Construction

The Avionics Handbook

Operation of Batteries 

1. Temperature

• Temperature Range - -20 degree Celsius to +70 degree Celsius  
• Optimum Performance range - -5 degree Celsius to 45 degree Celsius
• Charge and discharge testing should be done when battery temperature is between +15 to +35 degree Celsius.

2. Maintenance 

All maintenance should be done specifically in accordance with the instruction contained in corresponding Component Maintenance Manual (CMM). 

3. Ventilation

Battery ventilation and cooling accomplished by two methods. 

1.Tubes designed for the connection of the battery venting system. 

2.Holes in battery box.

Electronics emergency equipment requirements 

1.Fire Extinguishers
2.Water Extinguishers
3.Halon Extinguishers
4.Freon Extinguishers
5.Fire axes
6.Protective breathing equipment (PBE)
7.Fire Gloves
8.Torches
9.Oxygen
10.Megaphones

Cabin entertainment equipment

This includes passenger moving maps, LCD monitors,iPod docking stations, Blu-ray DVD players, and Glare shield flight cameras. The equipment provides real-time flight information, passenger entertainment, and safety briefings.

Aircraft Electrical Power (Part 1)