AUTOMATED ELECTRICAL PROTECTION SYSTEM FOR DOMESTIC APPLICATION

ARSHAD A K14S7F

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INTRODUCTION MAJOR FAULTS ELCB MCB SYSTEM OPERATION EXPERIMENTAL SETUP CONCLUSION REFERENCE

CONTENT

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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..

INTRODUCTION

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FAULTS

OVERCURRENT FAULT

OVERLOAD SHORTCIRCUIT

EARTHLEAKAGE FAULT

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Overcurrent fault is occur when the current exceeds the rated current carrying capacity of the conductor

There are two types: Short circuit

Over load

OVERCURRENT FAULT

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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

EARTH LEAKAGE FAULT

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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..

ELCB

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Contd…

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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..

MCB

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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.

Cont…

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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.

SYSTEM OPERATION

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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.

Power Recovery

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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.

Fault Location Detection

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Cont….

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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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Components

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.

EXPERIMENTAL SETUP

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This test is to verify that the system is able to detect normal condition, at which power is ON.

A. Normal Condition

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This section is to test the functionality of automatic ELCB reset operation.

B. Auto-Reset ELCB

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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.

C. MCB Check Operation

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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.

CONCLUSION

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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

REFERENCES

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THANK YOU

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