Electrical energy is generated in the generators’ stations, it distributes to the different loads in different places in the company. So distribution of electrical energy via electrical cables which have insulators.
In these electrical cables faults may occur such as earth fault or short-circuit fault and cause problems in a company. Therefore I design a system to detect earth fault and short circuit fault occur in a 3-Phase electrical cables so as it will help easy in determining cable faults and fix the problem.
PROBLEM STATEMENT
Due to the problem facing electrician, during troubleshooting of 3-Phase electrical cables. They are getting hard time to determine the faults such earth fault or short circuit fault, and find where it has occurs. Also a lot of time and energy at the time of finding the faults because they are using local method(they are using instrument tester) to determine the faults in a cable. Due to that problem, the activities of that area stops and it may lead to the low production or no production.
PROJECT OBJECTIVE
The main objective of this project is to detect the earth fault and short circuit faults occur in 3-Phase electrical cables by using the fast and accurate system.
SIGNIFICANCES
Saves time when finding the faults.
It will have the ability to detect the faults very fast and accurately.
Provides the accuracy information.
LITERATURE REVIEW
THE EXISTING SYSTEM
Testing instrument is a device that allows measurement of different quantities such as current, voltage, and resistance; the functions are always available through a selector switch. 3- Phase electric cable transmission and distribution of electric power. By using testing instrument a short circuit fault can be detected when there is continuity between the conductors or earth fault can determined.
Block diagram of existing system
Disadvantages of existing system
Time consuming
The system is based on manual operation
Fault distance cannot be indicated hence may cause the whole cable to be replaced instead of fixing the fault part.
Block diagram of proposed system
Advantages of proposed system
It will be faster and more accurate.
Able to display the phase fault line and indicates the type of fault.
Save time during the troubleshooting of cable fault.
DATA
Type of a cable- 3-Phase electric cable
Material made- Copper
Size of a cable- 2.5mm²
Length of a cable- 30m
Resistivity of a cable- 1.7*10¯⁸Ω-m
3 Phase voltage supply- 380V
Single phase AC supply- 220V- 240V,
cable length- 30m
Resistivity of cable- 1.72 x 10¯⁸ Ω−m
CSA- 2.5mm²
Required the resistance of the cable
from, R=ƥL∕A
R = (1.72 x 10¯⁸ Ω−m) x (30m)
2.5mm²
R= 0.206Ω
For go and return of a cable the resistance will be
=0.206Ω x 2
=0.412Ω
In a short circuit
I= V∕R.
During short circuit the resistance of a cable is in small range
approximately to zero, R=0.
for a given value of voltage,
V=380volts of three phase.
For any given value of voltage, when short circuit the resistance becomes zero and the current will be very high approximately to infinity.
CONCLUSION
Generally, the project is neither hard or simple but it requires a great knowledge hence it based on different fields such as electronics and computer fields. The project has not yet completed due to inadequate amount of funds to afford the equipment.
RECOMMENDATION
I recommend more advices and ideas to be shared so as to improve this project until its implementation.
Also I recommend various indicating system such light emitting diodes and sounding system such as buzzer so as to improve this circuit efficiency.
I recommend that, our electrical department should have enough and modern electrical equipment to be used in projects. This will help students to complete their projects well at a required time.