INTRODUCTION
Battery
A battery is a device consisting of one or more
electrochemical cells with external connections for powering
electrical devices.
Two chemistries are generally used for today’s aircraft
batteries :
 nickel cadmium (Ni-Cd) and lead-acid.
Lead-acid batteries are either vented or valve
regulated (VRLA), and are typically used in light and general
aviation aircraft. Vented Ni-Cd batteries dominate larger
aircraft and helicopter applications while both VRLA and Ni-Cd
types are found in smaller aircraft such as business jets.
SAFETY RULES
Physical
 Handling: the battery is heavy. When you lift it, bend your legs and not
your back.
 Use protective shoes.
Electrical
 Do not wear rings, watches, chains, belt buckles, necklaces or any other
metallic objects.
 Use insulated tools.
Chemical
 Electrolyte is very corrosive and can damage the skin: use gloves and
an apron.
 Electrolyte is very dangerous for eyes, use protective goggles
 Potassium hydroxide in the electrolyte can cause eczema.
SAFETY RULES
Physical
 Handling: the battery is heavy. When you lift it, bend your legs
and not your back.
LEAD-ACID BATTERIES
Dry charged cell lead-acid batteries, also known as
flooded or wet batteries, are assembled with electrodes (plates) that
have been fully charged and dried. An aircraft storage battery consists
of 6 or 12 lead-acid cells connected in series. The open circuit voltage
of the 6 cell battery is approximately 12 volts, and the open circuit
voltage of the 12-cell battery is approximately 24 volts.
NICD BATTERIES
A NiCd battery consists of a metallic box,
usually stainless steel, plastic-coated steel, painted steel,
or titanium containing a number of individual cells. These
cells are connected in series to obtain 12 volts or 24
volts. The cells are connected by highly conductive nickel
copper links. Inside the battery box, the cells are held in
place by partitions, liners, spacers, and a cover
assembly. The battery has a ventilation system to allow
the escape of the gases produced during an overcharge
condition and provide cooling during normal operation.
NICD BATTERIES
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The
batteries
are
connected to the
Aircraft System:
According to the aircraft
manufacturer, to start the
engine or the APU.
On the ground, to provide
power before electrical
power is supplied to the
aircraft systems.
In flight, if a malfunction or
a failure occurs in the
power supply system.
NICD BATTERIES
NICD BATTERIES
NICD BATTERIES
Battery Ratings
Nickel-cadmium batteries are rated in terms of
capacity in ampere-hours (Ah) (rated capacity). A battery rated for
1C Ah indicates that the battery is rated at a value based upon a
discharge time of 1 hour at 23°C ± 3°C (73.4°F ± 5.4°F). In other
words, a battery with a rated capacity of 40 Ah (1C Ah) will deliver
no less than 40 A for one hour when new.
NICD BATTERIES
NICD BATTERIES
Charge
Charging results in the conversion of electrical
energy to stored chemical energy.The negative material
(cadmium hydroxide) gradually gains electrons and is converted
to metallic cadmium (Cd); the positive material is gradually
brought to a higher state of oxidation (loses electrons).
Discharge
Discharging results in the conversion of the
chemical energy stored in the cell to electrical energy. During
discharge, the chemical reactions which occurred in charging
are reversed. The active material (Cd) in the negative plates
gradually loses electrons and changes to cadmium hydroxide.
NICD BATTERIES
NICD BATTERIES
OPERATION
Temperature
Although Saft nickel-cadmium batteries are capable of
operating in a wide temperature range [-40°C (-40°F) to +71°C (+160°F)],
optimum performance is obtained between +5°C (+41°F) and +45°C(+113°F).
Charging is inefficent at temperatures below -30°C (–22°F) and is not
recommended above 57°C (135°F). Charging must be stopped at temperatures
above +71°C (+160°F).
Maintenance
All maintenance, including charging, discharging, should be
done specifically in accordance with the instructions contained in this manual or a
corresponding Component Maintenance Manual (CMM).
Ventilation
Battery ventilation and cooling is accomplished through two
methods. Most Saft batteries are equipped with tubes designed for the connection
of a battery venting system. In others, holes in the battery box allow for heat
dissipation and ventilation of any hydrogen produced.
NICD BATTERIES
TYPE OF MAINTENANCE
 PERIODICAL CHECK
(Adjustment of electrolyte levels)
 REGULAR CHECK
(Capacity test and Periodical check)
 GENERAL OVERHAUL
(Disassembly, Full cleaning, Assembly and Regular check)
NICD BATTERIES
When maintenance intervals are referred to in
OPERATING HOURS, it means the sum of the flight and
ground operation time when the battery is connected to the
aircraft network. The ratio of operating hours to flying hours
depends on the operator.
When maintenance intervals are referred to in
CALENDAR TIME it means the time the battery has been
installed and operating onboard the aircraft and does not
include storage periods
NICD BATTERIES
Periodical check
The periodical check consists essentially of
voltage and insulation checks, discharge of residual
capacity and charge with electrolyte level adjustment.
The main purpose of this periodical check is to replace
water which is consumed by electrolysis during battery
overcharge. It is normally applied between regular checks
but can be omitted if the water consumption measured at
the regular check is within allowable limits
NICD BATTERIES
PERIODIC CHECK
At
specific
intervals according
to aircraft use, or
every 3 months,
test the battery
according to the
fig- ure.
NICD BATTERIES
VISUAL INSPECTION

Visual inspection should be done each time the battery is
removed for maintenance ;

Visually check each cell for any evidence of electrolyte
leakage. If there is salt or electrolyte traces do a General
overhaul.

Inspect the links and all upper nuts or screw, and washers. The
hardware should be free of bends, tarnish, corrosion, burns, or
any loss of nickel plating.

Check the main power connector for evidence of arcing,
corrosion, cracks, or cross-threaded terminals. Replace any
defective connectors.
NICD BATTERIES
VISUAL INSPECTION

Visual inspection should be done each time the battery
is removed for maintenance ;

Inspect the thermistor, thermostat, and/or thermocouple
assemblies (as applicable) for any damaged or loose
wire connections, cracks, dents, or other physical
damage.

Visually check all wiring insulation to ensure there is no
evidence of cracks, cuts, or bubbling.

Inspect the battery box and cover for any damage.
NICD BATTERIES
INSULATION CHECK
On a completely assembled battery, use a
megahmmeter, set to 250 V DC, to measure
the insulation resistance between the positive
terminal of each cell and the battery box .
NICD BATTERIES
INSULATION CHECK
NICD BATTERIES
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NUT TIGHTNESS
Tighten and check the torque of all upper cell nuts (refer to
FITS AND CLEARANCES).
POLARIZATION TEST
Charge the battery at 0.1C A for 1.5 hours. Keep the battery in
open circuit for 1 hour. Measure the open circuit voltage of each cell.
If any cell is zero (0) V or negative polarity, do a General overhaul.
RESIDUAL DISCHARGE
Discharge the battery at the 1C A or 0.5C A rate until each cell
in the battery is discharged to 1.0 volt or be low.
ADJUST ELECTROLYTE LEVEL
Electrolyte level adjustment is to be done during the last 15-30
minutes of the 4 hours Final charge at 0.1C A rate of charge.
NICD BATTERIES
CHARGE
 Check cell voltage at the beginning of the charge. If any cell
indicates an immediate voltage rise above 1.5 V, add 5 cm3
of distilled or deionized water to that cell.

During the last 15-30 minutes of the Final
charge cycle, Adjust electrolyte level.
NICD BATTERIES
RAPID PARTIAL CHARGE
One of the following two procedures can be
used in an emergency situation to charge the battery
to approximately 80% of its capacity. Do not use
these procedures for charging the battery during
normal maintenance.

Charge the battery at 0.5C A until the battery reaches an
average of 1.55 V/cell. Do not charge for more than 2 hours
and 30 minutes.
 Charge the battery at 1C A until the battery reaches an
average voltage of 1.57 V/cell. Do not charge for more than
1 hour and 15 minutes.
NICD BATTERIES
CHARGING
NICD BATTERIES
REGULAR CHECK
At
specific
intervals
according
to
aircraft use, or
AFTER
A
MAXIMUM OF 6
MONTHS, test the
battery according
to the figure.
NICD BATTERIES
REGULAR CHECK
CELL SHORTING
As each cell’s voltage drops below 1.0 V, connect
an equalizing resistor across each cell’s terminals. Leave
the resistors in place for 12 to 16 hours to allow each cell
to completely discharge and the battery to cool.
CAPACITY CHECK
Discharge the battery at 1C A. Record the time
that the first cell reaches 1.0 volt. This time must be
equal or greater to 51 min for VO and VP and 1 h for
VHP, VXP, CVH, CVD and CVK cells. .
NICD BATTERIES
GENERAL OVERHAUL
At
specific
intervals
according
to
aircraft use, or
AFTER
A
MAXIMUM
OF
ONE YEAR, test
the
battery
according to the
figure.
NICD BATTERIES
SPECIAL TOOLS, FIXTURES, EQUIPMENT
AND CONSUMABLES

.
NICD BATTERIES
SPECIAL TOOL
NICD BATTERIES
SPECIAL TOOL
NICD BATTERIES
TOOL KIT
NICD BATTERIES
TOOL KIT
NICD BATTERIES
RECYCLING
Nickel-cadmium batteries contain
nickel, cadmium, and potassium hydroxide
and should be disposed of properly. In all
cases, rely on local and national regulations
for proper battery disposal and/or shipping
to an appropriate recycling location.
Aircraft electrical
BASIC ELECTRIC
Components of Aircraft Electrical System
1. Generators
2. Batteries
3. Bus-bars
4. Transformer Rectifiers
5. Inverters
6. Switches
7. Micro-switches
8. Proximity switches
9. Circuit breakers
10.Relays and Contactors
11.Fuses
12 Motors
BASIC ELECTRIC
1. Generator
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A generator is a machine that converts
mechanical energy into electrical energy by
the process of electromagnetic induction.
There are two types of the generator – AC
generator, and DC generator. In both AC and
DC types of generator, the voltage induced is
alternating. The major difference between both
generators being in the method by which the
electrical energy is collected and applied to the
circuit externally connected to the generator.
BASIC ELECTRIC
2. Battery
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A battery is a device made up of a number of cells that depend on
battery utilization. The cells convert chemical energy into electrical
energy.
A battery may be of the primary cell type or secondary cell type.
Both types of cells exchange the electrons due to the chemical
action of an electrolyte and electrode materials.
The difference between the two cells is in the action that occurs
during discharge.
Primary cells destroy the active materials of the cell, however
secondary cells convert the active material into from which they can
subsequently be electrically reconverted into the original materials.
The action of re-conversion is more commonly known as charging.
The batteries selected for use in aircraft, therefore, employ
secondary cells and are either of the lead-acid or nickel-cadmium
types.
BASIC ELECTRIC
3. Bus-Bar
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The output from generators and batteries is supplied to busbars. Then all electrical services take their supplies from the
bus-bars.
Aircraft electrical services can be split into the following groups:
Vital Services – Services would be required after an emergency.
Components take their supply from the “hot” battery bus or vital
battery bus. The emergency lights are also powered from this
bus with their own battery back-up.
Essential Services – Services required to ensure a safe landing
in an in-flight emergency. The bus-bars are connected in such a
way that they can be fed from a generator or battery. Usually
called a DC essential bus and an AC essential bus.
Non-essential Services – Services that can be isolated in an inflight situation eg, galley supplies, in-flight entertainment, etc.
They can also be subject to load shedding. The actual name
may vary but there will be a non-essential ac bus and a nonessential dc bus.
BASIC ELECTRIC
4. Transformer Rectifiers
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These are often used to charge batteries from AC generators.
Rectifiers – Rectifiers convert AC into DC. The process of
converting an ac supply to a dc supply is known as
rectification.
Transformer – Transformers are electrical components that
transfer electrical energy from one circuit to another through
inductively coupled electrical conductors. This only works
with AC. It has two coils. The primary coil is supplied with ac.
This ac supply causes it to produce an alternating magnetic
flux field. This alternating flux field cuts back and forth across
the secondary coil and induces an ac voltage into it. If the
secondary coil has fewer windings than the primary then the
voltage is reduced – if it has more windings then the voltage
is increased.
BASIC ELECTRIC
5. Inverters

These convert dc to ac and may be rotary or static.
A rotary inverter employs a dc motor driving an ac
generator and a static inverter employs a solidstate square wave generator. Rotary inverters are
very inefficient.
BASIC ELECTRIC
6. Switches

A switch is used to isolate the circuits. Some other
switch types are used to direct the current into predetermined parts of a circuit. Switches are
characterized by the number of poles, number of
switched positions, and type of switched contacts
(permanent or momentary).
7. Micro-switches

Micro-switches are used to sense if a device has
moved or has reached its limit of travel. They are
attached to the structure and the wiring is
connected to a control circuit. Micro-switches are
usually pushbutton switches.
BASIC ELECTRIC
7. Micro-switches

Micro-switches are used to sense if a device has moved or has
reached its limit of travel. They are attached to the structure
and the wiring is connected to a control circuit. Microswitches are usually pushbutton switches.
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Honeywell Microswitch - 37XL11YD-43 Switch, Micro. Custom hall Effect
Switch with Lever Actuation.
This is a Honeywell 3-pin Micro Switch with Hall Effect Sensor Assembly.
Hall-Effect Switch with Lever.
Connections: 3 Male 3/16" Quick Attach or SOlder Terminals.
Pins: 3-Pin = GND Minus, +Voltage, Output
Mechanically Operated by magnet inside plunger, has 2" long lever.
Unactuated
Output Voltage Normally High (Off) Solid State Switch for 5VDC. " Minus
Plus Zero ".
Dimensions are 1.1"(30mm) x 0.63"(16mm) x 0.40"(10mm).
Alternate P/Ns: 1589292, A02297
Genuine Honeywell - New Old Stock - Rare
Applications: For Harsh Explosive Operating Environments (Non-Sparking).
Proudly Made in USA
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BASIC ELECTRIC
8. Proximity switches
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Proximity switches used in similar locations to micro-switches
like cargo doors, passenger doors, and landing gear UP and
DOWN locks
Proximity switches open or close an electrical circuit when they
make contact with or come within a certain distance of an object.
They are most commonly used in manufacturing equipment,
robotics, and security systems. There are four basic types: infrared,
acoustic, capacitive, and inductive.
Infrared proximity switches work by sending out beams of invisible
infrared light. A photodetector on the switch detects any reflections
of this light, which allow the device to determine whether there is an
object nearby. As a switch with just a light source and photodiode is
susceptible to false readings due to background light, more complex
models modulate the transmitted light at a specific frequency and
have receivers which only respond to that frequency. Even more
complex sensors are able to use the light reflected from an object to
compute its distance from the sensor.
BASIC ELECTRIC
9. Relays and Contactors
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A relay is simply an electro-mechanical switch where a small
amount of current can control a large amount of current.
Relays and Contactors are almost the same things. Both
operate in the same way. The difference between them is
their physical construction and application.
Relays are generally used for low current applications.
Contactors are also known as breakers. Contactors are used
for switching higher currents. For example, the Contactor can
be used for connecting battery power to the aircraft. The
features of a contactor include the main power contacts and
auxiliary contacts used for indication and control of other
devices.
BASIC ELECTRIC
10. Circuit Breaker
The circuit breaker is commonly used in place of a fuse. It is
designed to break the circuit and stop the current flow when the
current exceeds a predetermined value. Unlike the fuse, the
circuit breaker can be reset; whereas the fuse or current limiter
must be replaced.
 A circuit breaker is an automatically
operated electrical switch designed to protect an electrical
circuit from damage caused by excess current from an overload
or short circuit. Its basic function is to interrupt current flow after
a fault is detected. Unlike a fuse, which operates once and then
must be replaced, a circuit breaker can be reset (either manually
or automatically) to resume normal operation.
 Circuit breakers are made in varying sizes, from small devices
that protect low-current circuits or individual household
appliance, up to large switchgear designed to protect high
voltage circuits feeding an entire city. The generic function of a
circuit breaker, or fuse, as an automatic means of removing
power from a faulty system is often abbreviated as OCPD (Over
Current Protection Device).
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BASIC ELECTRIC
11. Fuse
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In electronics and electrical engineering, a fuse is an electrical safety
device that operates to provide overcurrent protection of an electrical
circuit. Its essential component is a metal wire or strip that melts when
too much current flows through it, thereby stopping or interrupting the
current. It is a sacrificial device; once a fuse has operated it is an open
circuit, and must be replaced or rewired, depending on its type.
Fuses have been used as essential safety devices from the early days
of electrical engineering. Today there are thousands of different fuse
designs which have specific current and voltage ratings, breaking
capacity, and response times, depending on the application. The time
and current operating characteristics of fuses are chosen to provide
adequate protection without needless interruption. Wiring regulations
usually define a maximum fuse current rating for particular
circuits. Short circuits, overloading, mismatched loads, or device failure
are the prime or some of the reasons for fuse operation. When a
damaged live wire makes contact with a metal case that is connected to
ground, a short circuit will form and the fuse will melt.
A fuse is an automatic means of removing power from a faulty system;
often abbreviated to ADS (Automatic Disconnection of Supply). Circuit
breakers can be used as an alternative to fuses, but have significantly
different characteristics.
BASIC ELECTRIC
12. Motors
Electric
motor is the electro-mechanical machine which
converts the electrical energy into mechanical energy. In other
words, the devices which produce rotational force is known as
the motor. The working principle of the electric motor mainly
depends on the interaction of magnetic and electric field.The
electric motor is mainly classified into two types. They are the
AC motor and the DC motor. The AC motor takes alternating
current as an input, whereas the DC motor takes direct current.
BASIC ELECTRIC
Types of Electric Motor

The classification of an electric motor is
shown in the figure below.
Fuel booster pump
FUEL BOOSTER PUMP
Introduction
2. Testing and trouble shoot
3. Disassembly
4. Cleaning
5. Check
6. Repair
7. Assembly
8. Fit and Clearance
9. Special Tools and Equipment
10. Illustrate Part Catalog
1.
INTRODUCTION
INTRODUCTION
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TESTING AND TROUBLESHOOTING
TEST AND TROUBLE SHOOTING
DISASSEMBLY
DISASSEMBLY
DISASSEMBLY
DISASSEMBLY
DISASSEMBLY
DISASSEMBLY
CLEANING
CLEANING
CHECK
CHECK
CHECK
CHECK
REPAIR
REPAIR
REPAIR
REPAIR
REPAIR
REPAIR
REPAIR
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
ASSEMBLY
FITS AND CLEARANCE
FIGURE PART CATALOG
Starter generator
STARTER GENERATOR
DESCRIPTION
2. OPERATION
3. DISASSEMBLY
4. CLEANING
5. INSPECTION
6. REPAIR
7. ASSEMBLY
8. TESTING
9. TROUBLESHOOTING
10. STORAGE INSTRUCTION
11. ILLUSTRATE PART LIST
12. MODEL DIFFERENCES
1.
DESCRIPTION
OPERATION
OPERATION
DIASSEMBLY
DIASSEMBLY
DIASSEMBLY
CLEANING
CLEANING PROCEDURE
INSPECTION
INSPECTION
REPAIR
REPAIR
REPAIR DIMENSIONS
ARMATURE
REPAIR
BALANCING ARMATURE
BEARING LINIER REPAIR
DIMENTION
REPAIR
REPAIR
REPAIR DIMENSION
REPAIR
REPAIR
REPAIR
ASSEMBLY
ASSEMBLY
ASSEMBLY
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TESTING
TROUBLESHOOTING
TROUBLESHOOTING
ILLUSTRATE PART LIST
ILLUSTRATE PART LIST