2. Electrical Installations
The electrical installation is an assembly of components
that allows you to reliably and safely use electrical
power.
3. Electrical system
Generation (11-25kV)
Transmission (400kV-66kV)
Distribution
Primary distribution(33-11kV)
Secondary distribution (400-220V)
Presence of switchgear in the electrical system
15-02-
2023
3
4. LT Switchgear
All equipments associated with the fault clearing process are
covered by the term “switchgear”.
LT Switchgear means “Low Tension switchgear”.
It is basically low voltage switchgear.
Components of LT Switchgear
Switches, fuses, circuit breakers, isolators, relays, control panel,
CTs , PTs and few minor elements
Purpose of using LT Switchgear
For the over-current fault protection and/or protection against thermal
overloading .
5. Switch Fuse Unit
It has one switch unit
and one. fuse unit.
When we operate the
breaker, the contacts
will. get closed
through switch and
then the supply will
pass.
6. Switch Fuse Unit (SFU)
Switch Fuse Unit (SFU) features :
The fuse is the oldest form of protection and still in use.
Re-wirable fuse and high rupturing capacity (HRC).
The standard fuse current rating is 6, 10, 16, 20, 25, 32, 40, 50, 63, 80, 100,
125, 1600, 200, 250, 315, 350, 400, 500, 6300, 800 amp to 1000 amp.
It is used at industry particularly in motor circuit.
Types of SFU: Industrial and commercial and domestic type.
Advantages of fuse :
No mechanical operating mechanism; reliable
It is fast acting
It can be used in draw out type switchboard modules
Disadvantages of fuse :
Replacement required.
Time required to replace increases the interruption time.
Unable to protect overloading .
7. Miniature circuit breaker (MCB)
Low voltage power fuses are being replaced by MCCB and MCBs.
1. Single Pole 2. Double Pole 3. Three Pole 4. Four pole MCB
8. MCB Types:
Single Pole : Neutral is shorted and connected always and the live
wire is connected with the circuit through the fuse wire .
Double Pole : Both the line and neutral wires are connected with the
two terminals of the circuit through the two fuse wires.
Three Pole : It is used for three phases : R, Y & B . The three lines
are connected with the three phase load or circuit with the help of
three fuse wires. The neutral wire is always shorted.
Four Pole : It is used for three phases : R, Y & B along with the
neutral. The three lines are connected with the three phase load or
circuit with the help of three fuse wires. The neutral wire is also
connected with the neutral point of the three phase load by the forth
fuse wire.
9. MCB features :
An MCB or miniature circuit breaker is used for load break,
isolation and protection of a circuit.
MCB can provide thermal overloading as well as short circuit
protection.
Bi -matelic strips are used here instead of fuse wire.
Operation is similar like ACB. The main function of an MCB is to
switch the circuit, i.e., to open the circuit (which has been
connected to it) automatically when the current passing through it
(MCB) exceeds the value for which it is set. It can be manually
switched ON and OFF.
MCBs are available in the standard current ratings of 6-125 A
Fault level cleared 50 kA and above.
Industrial and commercial and domestic type.
MCB can typically perform 20000 mechanical and 2000-10000
electrical operations
11. MCCB features :
An MCCB is also used for load break, isolation and protection of a sub-circuit.
Extensive application of MCCB is at the junction points of multiple sub-circuits.
MCCB replaces ACB and switch fuse unit in their current range.
Operation is similar like ACB. The main function of an MCCB is to switch off or open the
faulty sub-circuit (which has been connected to it) automatically , when the current
passing through it (MCCB) exceeds the value for which it is set. It can be manually
switched ON and OFF. It will keep the connection of the healthy sub-circuits connected
to it.
Bi -matelic strips are used here instead of fuse wire.
MCB can provide thermal overloading as well as short circuit protection.
MCBs are available in the standard current ratings of 6-6000 A
Fault level cleared 15-100kA.
Industrial and commercial and domestic type.
MCCB less than 250 A can typically perform 40000 mechanical and 20000 electrical
operations.
MCCB more than 250 A can typically perform 15000 mechanical and 4000 electrical
operations.
MCCB can provide thermal overloading as well as short circuit protection along with
Adjustable time delay
Instantaneous operations.
12. ACB means “Air Circuit Breaker”
Air Circuit Breaker (ACB) is an
electrical device used to
provide Over-current and
short-circuit protection for
electric circuits over 800 Amps
to 10K Amps. These are usually
used in low voltage
applications below 450V. The
air circuit breakers have
completely replaced oil circuit
breakers.
13. LT Wires and Cables
Cables are used to connect equipments and are the nerves of an electrical
system.
Low Voltage Cables come in a variety of sizes, materials, and types, each
particularly adapted to its uses. Cables consist of three major components:
conductors, insulation, and protective outer sheath. The makeup of individual
cables varies according to application. Types of LT cables are-
Power cables
Control cables
Earthing cables
Instrumentation/communication cables (mainly wiring of instruments)
• These are found as Fire Rated (FR) cables
• The outer sheath is either red or orange
• The insulation and outer sheath are flame retardant
• A flame barrier is in between conductor and insulation
• It is resistant to fire also
14. LT Power Cables
Low voltage power cable (PVC or XLPE)
The basic construction of a low-voltage polyvinyl
chloride (PVC) or cross linked polyethylene (XLPE)
cable is as follows:
Stranded Al or soft-drawn copper conductor with
circular or shaped cross-section
Extruded PVC or XLPE insulation over individual
conductor
Single core/ multi-core
An outer PVC sheath
16. Conductor
Conductor material; Al or Cu
Resistivity (0.0280 or 0.0172unit at 20 degree C)
Melting point (660 or 1083unit)
Tensile strength (10 or 25unit)
Temperature coefficient of resistance (0.00404 or
0.00393unit)
Cu conductors either hard-drawn (arial cables and
overhead conductor) or soft-drawn (cable)
Al conductors available in three hardness: H4
(underground cables), H68 (underground cables) and H9
(arial cables and overhead conductor).
18. Features of Earthing:
Apart from home protection , the neutral of the transformers and
generators, metal enclosures and supports of the equipments are
connected to earth.
The objectives are:
To reduce the risk of fire, electrical hazards, electrocution and
overvoltage.
There may be unearthed systems also but insulation will be damaged
chronologically.
The different types of earthing :
Solidly earthed system
Resistance earthed system
19. Types of Earthing
Solidly earthed system: The neutral of the transformers and
generators, metal enclosures and support of the equipment is
connected to earth by a conductor
Resistance earthed system: The neutral of the transformers and
generators, metal enclosures and support of the equipment is
connected to earth by a resistance.
High RES will be applicable in the area where earth fault current
is 5-25 A.
High RES will also limits the transient over voltage
Low RES will be applicable in the are where earth fault current is
50-2000 A.
For undergrounded high voltage systems, the earth fault currents
are higher than for an overhead system and hence neutral earthing
resistors may be required for undergrounded system.
20. Component of an earthing
system
Earth Wire : Most of them are made of stainless steel
rod, galvanized steel rod, galvanized steel pipe, copper
pipe
Earth electrodes
Vertical type
Plate type
Horizontal electrode
Earth bars
Earth conductors
21. Earth Leakage Circuit Breaker
(ELCB)
Earth Leakage Circuit Breaker or ELCB
If any current leaks from any electrical installation,
there must-be any insulation failure in the electrical
circuit, it must be properly detected and prevented
otherwise there may be a high chance of electrical shock
if-anyone touches the installation. An earth leakage circuit
breaker does it efficiently. The associated mechanism with
ELCB detects the earth leakage current and makes the
power supply off by opening the circuit breaker.
There are two types of earth leakage circuit breaker;
one is voltage ELCB and other is current ELCB.
22. Voltage ELCB ( Voltage Earth Leakage
Circuit Breaker)
The working principle of voltage ELCB is quite simple. One terminal
of the relay coil is connected to the metal body of the equipment to be
protected against earth leakage and other terminal is connected to the
earth directly.
If any insulation failure occurs or live phase wire touches the metal
body, of the equipment, there must be a voltage difference appears
across the terminal of the coil connected to the equipment body and
earth. This voltage difference produces a current to flow the relay coil.
23. If the voltage difference crosses, a predetermined limit, the current
through the relay becomes sufficient to actuate the relay for tripping
the associated circuit breaker to disconnect the power supply to the
equipment. The typicality of this device is, it can detect and protect
only that equipment or installation with which it is attached. It cannot
detect any leakage of insulation in other installation of the system.
24. Current ELCB or Residual
current device (RCD)
The working principle of current earth leakage circuit
breaker or RCCB is also very simple as voltage operated
ELCB but the theory is entirely different and residual
current circuit breaker is more sensitive than ELCB.
Actually, ELCBs are of two kinds, but it is general
practice to refer voltage based ELCB as simple ELCB.
And current based ELCB is referred as RCD or RCCB.
Here one CT core is energized from both phase wise and
neutral wire.
Actually, ELCBs are of two kinds, but it is general
practice to refer voltage based ELCB as simple ELCB.
And current based ELCB is referred as RCD or RCCB.
Here one CT core is energized from both phase wise and
neutral wire.
25. Single Phase Current ELCB or
Residual current device (RCD)
Single Phase Residual Current ELCB. The polarity of the phase winding
and neutral winding on the core is so chosen that, in normal condition
mmf of one winding opposes that of another. As it is assumed that, in
normal operating conditions the current goes through the phase wire
will be returned via neutral wire if there's no leakage in between. As
both currents are same, the resultant mmf produced by these two
currents is also zero-ideally. The relay coil is connected with another
third winding wound on the CT core as secondary. The terminals of this
winding are connected to a relay system. In normal operating
condition there would not be any current circulating in the third
winding as here is no flux in the core due to equal phase and neutral
current. When any earth leakage occurs in the equipment, there may
be part of phase current passes to the earth, through the leakage path
instead of returning via mental wire. Hence the magnitude of the
neutral current passing through the RCCB is not equal to phase current
passing through it.
27. Three Phase Current ELCB or
Residual current device (RCD)
Three Phase Residual Current Circuit Breaker or Current ELCB. When
this difference crosses a predetermined value, the current in the
third secondary winding of the core becomes sufficiently high to
actuate the electromagnetic relay attached to it. This relay causes
tripping of the associated circuit breaker to disconnect the power
supply to the equipment under protection. Residual current circuit
breaker is sometimes also referred as residual current device (RCD)
when we consider the device by disassociating the circuit breaker
attached to RCCB. That means, the entire parts of RCCB except
circuit breaker are referred as RCD.
29. Types of Batteries
NICKEL CADMIUM BATTERIES
The active components of a rechargeable NiCd battery in the
charged state consist of nickel hydroxide (NiOOH) in the positive
electrode and cadmium (Cd) in the negative electrode. For the
electrolyte, potassium hydroxide (KOH) is normally used. Due to their
low internal resistance and the very good current conducting
properties, NiCd batteries can supply extremely high currents and can
be recharged rapidly. These cells are capable of sustaining
temperatures down to -20°C. The selection of the separator (nylon or
polypropylene) and the electrolyte (KOH, LiOH, NaOH) influence the
voltage conditions in the case of a high current discharge, the service
life and the overcharging capability. In the case of misuse, a very
high-pressure may arise quickly. For this reason, cells require a safety
valve. NiCd cells generally offer a long service life thereby ensuring a
high degree of economy.
30. NICKEL METAL HYDRIDE BATTERIES
The active components of a rechargeable NiMH battery in the
charged state consist of nickel hydroxide (NiOOH) in the positive
electrode and a hydrogen storing metal alloy (MH) in the negative
electrode as well as a potassium hydroxide (KOH)
electrolyte. Compared to rechargeable NiCd batteries, NiMH
batteries have a higher energy density per volume and weight.
LITHIUM ION BATTERIES
The term lithium ion battery refers to a rechargeable battery
where the negative electrode (anode) and positive electrode
(cathode) materials serve as a host for the lithium ion
(Li+). Lithium ions move from the anode to the cathode during
discharge and are intercalated into (inserted into voids in the
crystallographic structure of) the cathode. The ions reverse
direction during charging.
31. Since lithium ions are intercalated into host materials during charge
or discharge, there is no free lithium metal within a lithium-ion
cell. In a lithium ion cell, alternating layers of anode and cathode
are separated by a porous film (separator). An electrolyte composed
of an organic solvent and dissolved lithium salt provides the media
for lithium ion transport. For most commercial lithium ion cells, the
voltage range is approximately 3.0 V (discharged, or 0 % state-of-
charge, SOC) to 4.2 V (fully charged, or 100% SOC).
SMALL SEALED LEAD ACID BATTERIES
Rechargeable small sealed lead acid (SSLA) batteries, which are
valve-regulated lead acid batteries, (VRLA batteries) do not require
regular addition of water to the cells, and vent less gas than flooded
(wet) lead-acid batteries.SSLA batteries are sometimes referred to as
“maintenance free” batteries. The reduced venting is an advantage
since they can be used in confined or poorly ventilated spaces.
32. There are two types of VRLA batteries,
Absorbed glass mat (AGM) battery
An absorbed glass mat battery has the electrolyte absorbed in a
fiber-glass mat separator.
Gel battery (“gel cell”)
A gel cell has the electrolyte mixed with silica dust to form an
immobilized gel.
NOTE : SSLA/VRLA batteries include a safety pressure relief valve. As
opposed to flooded batteries, a SSLA battery is designed not to spill
its electrolyte if it is inverted.
33. Battery is a source of DC supply
Used to provide DC control supply to electrical switchboards
Secondary batteries are used in residential, commercial and
industrial applications.
Battery is made of cells with series, parrllel and series-parallel
connections
Output voltage of one lead acid cell is 2V and the whole battery
can supply up to 12V-400V. Capacity of battery is provided by
ampere-hour.
Features of Batteries
34. Important Characteristics for
Batteries
There are many characteristics that can help to identify a
battery and we can distinguish the three main ones as:
chemistry, voltage and specific energy (capacity). However, if
the battery is only a starter, it also delivers cold cranking
amps (CCA), which permits to offer high current at cold
temperatures.
35. Chemistry
The main battery chemistries are lead, nickel and lithium. They all
need a specific designated charger, this is why charging these batteries on
a different charger from their own might cause an incorrect charge,
despite it may seem to work at first.
This happens because of the different regulatory requirement of each
chemistry.
Voltage
A battery features a nominal voltage. Along with the amount of cells
connected in series, chemistry provides the open circuit voltage (OCV),
which is about 5-7% higher on a fully charged battery.
It is important to check the correct nominal voltage of a battery before
connecting it.
36. Capacity
The capacity of a battery indicates the specific energy in
ampere-hours (Ah), which represents the discharge current that a
battery is able to issue over the course of time.
Installing a battery that has a higher Ah than indicated offers a
longer runtime, just as a smaller Ah provides a shorter runtime.
Moreover, charging a larger battery will take more time than
charging a smaller one, but the Ah divergence must not surpass
25%.
Cold cranking amps (CCA)
Every starter battery is marked with cold cranking amps, also
abbreviated CCA. The number denotes the amount of amps that
the battery is able to provide at -18°C.
37. Specific energy and energy density
Specific energy expresses the capacity of a battery in weight
(Wh/kg), and it can also be called gravimetric energy density. Energy
density, also called volumetric energy density, describes volume in liters
(Wh/l).
Those products that need a long runtime at moderate load are
optimized for high specific energy.
Specific power
Loading capability is designated by specific power, also called
gravimetric power density. Power tools need a battery made for high
specific power that features a lowered specific energy (capacity).
38. C-rates
C-rates indicate how much time a battery takes to charge or
discharge. If the battery is at 1C, it charges and discharges at a
current that is equal to the marked Ah rating; at 0,5C, the time
is doubled and the current is half; at 0,1C the time is 10-fold
and the current is one-tenth.
Load
Load describes the current drawn from a battery. The voltage
drops under load because of the internal battery resistance and
the state of charge (SoC), causing the end of discharge.
Power is measured in watts (W) and it represents the current
provided; energy is the physical work over the course of time
and it is indicated in watt-hours (Wh).
39. Watts and Volt-amps (VA)
Watts and Volt-amps (VA) represent, respectively, the real
power metered and the apparent power influenced by a
reactive load.
Watt and VA readings are equal if measured on a resistive load.
A reactive load triggers a phase shift between voltage and
current, causing the lowering of the power factor (pf) and the
ideal one (1) to 0,7 or less. The dimensioning of electrical
wiring and circuit breakers has to be based on VA power.
40. Charging
Float charging
The current is maintained constant till the float charge voltage is reached. Then
the voltage is held constant and the current is reduced.
Boost charging
Boost charging will be during discharging period. The charging current could be
10%-30% of the current corresponding to the 10-h capacity current. The charging
voltage is also higher here.
An ac voltage never be applied to battery, it heats and reduces battery
life
Constant voltage charging also allows a large current to circulate,
reduces battery life.
Typical discharge curve
Important point regarding battery
41. Elementary calculations for
Power factor improvement
Causes for poor power factor
Single phase and three phase induction Motors
Varying Load in Power System
Industrial heating furnaces
Electrical discharge lamps
Transformers
42. Methods for Power Factor Improvement
The following devices and equipment are used for Power factor
Improvement.
Static Capacitor
Synchronous Condenser
Phase Advancer
43. Static Capacitor
We know that most of the industries and power system loads are
inductive that take lagging current which decrease the system power
factor. For Power factor improvement purpose, Static capacitors are
connected in parallel with those devices which work on low power
factor.
These static capacitors provides leading current which neutralize
(totally or approximately) the lagging inductive component of load
current (i.e. leading component neutralize or eliminate the lagging
component of load current) thus power factor of the load circuit is
improved.
These capacitors are installed in Vicinity of large inductive load e.g
Induction motors and transformers etc, and improve the load circuit
power factor to improve the system or devises efficiency.
44. Circuit diagram of the inductive load without and with
static capacitor along with their phasor diagrams
45. Explanation :
Suppose,here is a single phase inductive load which is taking lagging
current (I) and the load power factor is Cosθ as shown in fig-1.
In fig-2, a Capacitor (C) has been connected in parallel with load.
Now a current (Ic) is flowing through Capacitor which lead 90° from
the supply voltage ( Note that Capacitor provides leading Current
i.e., In a pure capacitive circuit, Current leading 90° from the
supply Voltage, in other words, Voltage are 90° lagging from
Current). The load current is (I). The Vectors combination of (I) and
(Ic) is (I’) which is lagging from voltage at θ2 as shown in fig 3.
It can be seen from fig 3 that angle of θ2 < θ1 i.e. angle of θ2 is less
than from angle of θ2. Therefore Cosθ2 is less than from Cosθ1
(Cosθ2> Cosθ1). Hence the load power factor is improved by
capacitor.
Also note that after the power factor improvement, the circuit
current would be less than from the low power factor circuit
current. Also, before and after the power factor improvement, the
active component of current would be same in that circuit because
capacitor eliminates only the reactive component of current. Also,
the active power ( in Watts) would be same after and before power
factor improvement.
46. Advantages:
Capacitor bank offers several advantages over other methods of power
factor improvement.
Losses are low in static capacitors
There is no moving part, therefore need low maintenance
It can work in normal conditions (i.e. ordinary atmospheric conditions)
Do not require a foundation for installation
They are lightweight so it is can be easy to installed
Disadvantages:
The age of static capacitor bank is less (8 – 10 years)
With changing load, we have to ON or OFF the capacitor bank, which
causes switching surges on the system
If the rated voltage increases, then it causes damage it
Once the capacitors spoiled, then repairing is costly
47. Synchronous Condenser
When a Synchronous motor operates at No-Load and over-exited then
it’s called a synchronous Condenser. Whenever a Synchronous motor is
over-exited then it provides leading current and works like a capacitor.
When a synchronous condenser is connected across supply voltage (in
parallel) then it draws leading current and partially eliminates the re-
active component and this way, power factor is improved. Generally,
synchronous condenser is used to improve the power factor in large
industries.
48. Advantages:
Long life (almost 25 years)
High Reliability
Step-less adjustment of power factor.
No generation of harmonics of maintenance
The faults can be removed easily
It’s not affected by harmonics.
Require Low maintenance (only periodic bearing greasing is necessary)
Disadvantages:
It is expensive (maintenance cost is also high) and therefore mostly
used by large power users.
An auxiliary device has to be used for this operation because
synchronous motor has no self starting torque
It produces noise
49. Phase Advancer
Phase advancer is a simple AC exciter which is connected on the
main shaft of the motor and operates with the motor’s rotor circuit
for power factor improvement. Phase advancer is used to improve
the power factor of induction motor in industries.
As the stator windings of induction motor takes lagging current 90°
out of phase with Voltage, therefore the power factor of induction
motor is low. If the exciting ampere-turns are excited by external
AC source, then there would be no effect of exciting current on
stator windings. Therefore the power factor of induction motor will
be improved. This process is done by Phase advancer.
50. Advantages:
Lagging kVAR (Reactive component of Power or reactive power) drawn
by the motor is sufficiently reduced because the exciting ampere turns
are supplied at slip frequency (fs).
The phase advancer can be easily used where the use of synchronous
motors is Unacceptable
Disadvantage:
Using Phase advancer is not economical for motors below 200 H.P.
(about 150kW)
51. Power Factor Improvement in single phase and three phase star &
delta connections
Power factor improvement in three phase system by connecting a
capacitor bank in
(1). Delta connection
(2). Star Connection)
52. Calculation for power factor
improvement
Example: 1
A 3 Phase, 5 kW Induction Motor has a P.F (Power factor) of 0.75
lagging. What size of Capacitor in kVAR is required to improve the P.F
(Power Factor) to 0.90?
Solution (Classical Calculation Method)
Motor input = P = 5 kW
Original P.F = Cosθ1 = 0.75
Final P.F = Cosθ2 = 0.90
θ1 = Cos-1 = (0.75) = 41°.41; Tan θ1 = Tan (41°.41) = 0.8819
θ2 = Cos-1 = (0.90) = 25°.84; Tan θ2 = Tan (25°.50) = 0.4843
53. Required Capacitor kVAR to improve P.F from 0.75 to 0.90
Required Capacitor kVAR = P (Tan θ1 – Tan θ2)
= 5kW (0.8819 – 0.4843)
= 1.99 kVAR
And Rating of Capacitors connected in each Phase
1.99/3 = 0.663 kVAR
54. Example 2:
An Alternator is supplying a load of 650 kW at a P.F (Power factor) of 0.65.
a) What size of Capacitor in kVAR is required to raise the P.F (Power
Factor) to unity (1)? b) And how many more kW can the alternator supply
for the same kVA loading when P.F improved.
Solution (Classical Calculation Method)
a) Supplying kW = 650 kW
Original P.F = Cosθ1 = 0.65
Final P.F = Cosθ2 = 1
55. θ1 = Cos-1 = (0.65) = 49°.45; Tan θ1 = Tan (41°.24) = 1.169
θ2 = Cos-1 = (1) = 0°; Tan θ2 = Tan (0°) = 0
Required Capacitor kVAR to improve P.F from 0.75 to 0.90
Required Capacitor kVAR = P (Tan θ1 – Tan θ2)
= 650kW (1.169– 0)
= 759.85 kVAR
b) We know that P.F = Cosθ = kW/kVA . . .or
kVA = kW / Cosθ
= 650/0.65 = 1000 kVA
When Power Factor is raised to unity (1)
No of kW = kVA x Cosθ
= 1000 x 1 = 1000kW
Hence increased Power supplied by Alternator
1000kW – 650kW = 350kW
56. Example: 3
A Single phase 400V, 50Hz, motor takes a supply current of 50A at a P.F
(Power factor) of 0.6. The motor power factor has to be improved to 0.9 by
connecting a capacitor in parallel with it. Calculate the required capacity of
Capacitor in both kVAR and Farads.
Solution (Classical Calculation Method)
Motor Input = P = V x I x Cosθ
= 400V x 50A x 0.6
= 12kW
Actual P.F = Cosθ1 = 0..6
Required P.F = Cosθ2 = 0.90
57. θ1 = Cos-1 = (0.60) = 53°.13; Tan θ1 = Tan (53°.13) = 1.3333
θ2 = Cos-1 = (0.90) = 25°.84; Tan θ2 = Tan (25°.50) = 0.4843
Required Capacitor kVAR to improve P.F from 0.60 to 0.90
Required Capacitor kVAR = P (Tan θ1 – Tan θ2)
= 5kW (1.3333– 0.4843)
= 10.188 kVAR
58. kVAR = 10.188 … (i)
We know that;
IC = V/ XC
Whereas XC = 1 / 2 π F C
IC = V / (1 / 2 π F C)
IC = V *(2 π F C )
= (400) x 2π x (50) x C
59. IC = 125663.7 x C
And,
kVAR = (V x IC) / 1000 … [kVAR =( V x I)/ 1000 ]
= 400 x 125663.7 x C
KVAR = 50265.48 x C … (ii)
Equating Equation (i) & (ii), we get,
50265.48 x C = 10.188
C = 10.188 / 50265.48
C = 2.0268 x 10-4
C = 202.7 x 10-6
C = 202.7μF
60. Battery Backup :
Battery backup is required for uninterrupted power supply
for a specific period of time.
Battery Backup Circuit Diagram
