Power system protection is the most important requirement in the Industrial or Domestic electrical to prevent equipment from damage cause by leakage current. This project is designed due to control a circuit breaker by using a password for the safety of a lineman or electrical equipment during the maintenance.
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PROBLEM STATEMENT
The lives of technicians and safety of electrical machines have risk due to accidents involving electric shocks resulting from poor organization among maintenance technicians. That is when maintenance technicians switch off a power line and continue carrying out their maintenance work and another person who do not know whether maintenance work is going on will switch on the power line by which will cause the technicians to lose their lives because electric shock. Password based control circuit will ensure the safety of the lives of the technicians or line men since only maintenance engineer who knows the password of a particular
power line will be able to switch ON/OFF the specified power line.
SIGNIFICANCE
Avoid electrical accidents to technicians and equipment
Project is simple and easy to use
so commonly available components.
Brings comfortability of technicians and increases efficiency of work
EXISTING SYSTEM
Is an electromechanical circuit breaker which uses fuses in their distribution lines.
Power supply enters the distribution body which contain the switch gear and after
directly to the load .
Advantage of the system
Simple in construction
Disadvantage of the system
Does not ensure the safety of a technician on work
PROPOSED SYSTEM
The project is designed to trip the circuit with the help of a password.
The proposed system ensures the safety of the technician where by password are predefined in the system and thus technician or the electrician concerns has to enter the password to trigger the system on or switching off
SIGNIFICANCE OF THE PROPOSED SYSTEM
Ensures the safety of the technicians and other electrical machines during maintenance
Easy and simple to design
Easy to maintain and repair
Power consumed to each section by machines and other offices = 47500W
Maximum current that a contactor can sustain,
From,
P = IV
I=P/V
I = 47500/380
I = 125A.
This means to select a contactor that can sustain the amount of current above is to choose a bigger contactor that can carry more than the maximum capacity. For the best application, contactor with 150A will be most preferably.
Coil voltage of the contactor to be used also is an important aspect for selection of the contactor, in this case suitable voltage coil for the project is 220-250 single phase. That is 150A/250V.
Coil resistance = 400Ω
DC voltage supply for the relay = 12V
V = IR
I = V/R
current = 12V/400Ω
30mA.
Relay coil current is 30 mA.
Vb = VRB + VBE
VBE = 0.7V
VRB = Ib x RB
because VR, = Vb – VBE
VRB = 4.5V – 0.7V = 3.8V
but VR = 3.8V
RB = VRB/Ib
R = 3.8V/200µA
19KΩ
The resistors R2, R3, R4 have to be with values of 20KΩ each for better choice of proper working.
NB: the Vb ≈ 4.5V the voltage from the Arduino where by it has got some
components which has caused the voltage drop of 0.5V but the Arduino operates under 5V supply.
DATA ANALYSIS
This chapter presents the findings of the study, analysis and interpretation of the findings. The data
are analyzed in order to get good conclusion and recommendation of the project.
CONCLUSION
A perfect protection has been achieved to electrical technicians, in whilst of increase of technicians’
accident that happens while repairing the electrical lines and machines due to the lack of communication
between electrical maintenance staff and other workers. Finally, protective system has given to technicians’
protection.
The solve of this problem clarified on using a password to turn ON/OFF circuit breaker. It is not a teaser to turn OFF circuit breaker the issue is that to turn ON circuit breaker whilst electrical technicians on a task that may cause a fire , blast , burning , also we can’t ignore the damage that may cause burning the section this lead to financial losses.
The manual part is using the keypad to entering password that will appear on LCD screen to be absolute
about that you enter the password you pre-select. So the password will store on Arduino’s EEPROM and the output is to energize the relay, which it then allows current to flow to the contactor coil to make it energize and make or break the circuit. Here a safety has provided to the line technician because the
moving contact will not move unless the same password that line technician selected is entered.
RECOMMENDATIONS
When I implemented this project some obstacle appeared most of all solved, and little of it remained, therefor a lot of space for further improvement.
The project can be interfaced with the GSM modem for remote control of circuit breaker via SMS. So the circuit breaker can not only operate from a fixed position but also from a distance through
wireless communication hence it can also save time.