AUTOMATED ELECTRICAL PROTECTION SYSTEM FOR DOMESTIC APPLICATION

1. ARSHAD A K
14
S7F
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2.  INTRODUCTION
 MAJOR FAULTS
 ELCB
 MCB
 SYSTEM OPERATION
 EXPERIMENTAL SETUP
 CONCLUSION
 REFERENCE
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3.  Power reliability and continuity is very important and critical
to a domestic building..
 Single-phase is very common system used in domestic..
 Three common factors are faulty wiring in the house, improper
flexible cords, and faulty appliance..
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4. FAULTS
OVERCURRENT
FAULT
OVERLOAD SHORTCIRCUIT
EARTHLEAKAGE
FAULT
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5.  Overcurrent fault is occur when the current exceeds the rated
current carrying capacity of the conductor
 There are two types:
 Short circuit
 Over load
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6.  It exists when unintended path is established between the
normal current carrying conductors which has contact directly
or indirectly with earth.
 Earth leakage is residual current typically in very low current
range.
 If it increases a threshold for that device or circuit it becomes
earth fault which is essentially a short between phase and earth
or body
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7.  There are two types of ELCB: voltage operated and current
operated..
 The RCD operates by measuring the current balance between
two conductors using a differential current transformer..
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9.  The MCB is resettable protective device which designed to
isolate a circuit during an overcurrent (both overload and short
circuit) event without using fuse.
 MCB is choosing for building protection rather than fuse
because of its resettable capability.
 The mechanism of operation includes a movable handle that
extends at the outside of the housing..
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10.  The handle has basically three stable positions: on, off, and
tripped.
 The mechanism will respond to instantaneous high current to
open the contact and therefore interrupt the current flow.
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11.  The automatic system is designed for domestic electrical
system to auto-reset ELCB and auto-detection if any
permanent fault occurred.
 The system operation is divided into two parts:
 Power recovery
 Fault location detection.
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12.  Power recovery is a process of turning back the power ON
when electric power encounters unexpected shut down for a
period of time due to tripping or faults..
 Currently, for home electrical system, power recovery is
manually done..
 Once fault detected and isolated, ELCB will be switched ON
and supply is restored.
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13.  Domestic electrical fault would normally occur at individual
circuit, either switches or sockets.
 Fault location detection may facilitate the process of power
recovery to recover from unexpected power outage.
 Fault detection can be done through current difference
between the amount of current travelling into the load and the
current travelling out of the load.
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15.  Current Sensor
It is very important to select an accurate current sensor
in this project.
 The accuracy of current value measured by this current sensor
will lead to the accurateness of detecting fault location and
fault isolation from the main line.
 Arduino UNO Board
The Arduino UNO board is the main microcontroller board in
this project.
 All calculations and data collections will be done through this
board.
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16.  A circuit has been setup as in Fig. 3 with two current sensors
(line and neutral) connected to the input of Arduino board for
simulation purpose.
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17.  This test is to verify that the system is able to detect normal
condition, at which power is ON.
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18.  This section is to test
the functionality of
automatic ELCB reset
operation.
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19.  Once the ELCB reset operation reaches “Reset Test: 3”, and
the power is still “0”, the system will check each MCB since
MCB is installed at individual circuit.
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21.  Automated Electrical Protection System or Auto-EProS can be
considered as a new invention in electrical protection field.
 It is an additional feature to the electrical protection system to
enhance the performance of domestic protection system.
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22.  Stevenson, William D., Jr., “Elements of Power Systems
Analysis”,McGraw-Hill Electrical And Electronic Engineering
Series
 Electrical Safety Hazards Handbook”, Littelfuse USA, 2005
 QO and QOB Miniature Circuit Breakers with Ground Fault
Protection, Schneider Electric, 2009
 “Residual Current Device”. [Online] Retrieved from
http://en.wikipedia.org/ wiki/Residual-current device
 “Difference between Fuse and Circuit Breaker”. [Online]
Retrieved from http://www.wisegeek.com/what-is-the-
difference-between-a-fuseand- a-circuit-breaker.htm
 Miniature Circuit Breakers: Application Guide”, ABB Inc., USA,
Apr 2009
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