Design And Construction Of A Single Phase Automatic Change Over Switch With Phase Selector
The design and construction of a single-phase automatic changeover switch with a phase selector involves creating a reliable device that facilitates seamless transition between power sources while allowing the user to select the desired phase. This switch, essential for managing power supply in residential and small-scale commercial settings, combines robust mechanical and electrical components. It incorporates features such as automatic detection of power loss or restoration, ensuring uninterrupted operation. The phase selector enables users to switch between available phases, optimizing power usage based on requirements. Through meticulous engineering and assembly, this switch ensures safety, efficiency, and ease of use, enhancing the resilience of electrical systems in diverse settings, from homes to small businesses, thereby promoting energy management and reliability in electrical distribution networks.
Title page
Approval page
Certification
Dedication
Acknowledgement
Table of content
CHAPTER ONE
1.0 INTRODUCTION
1.1 Aims and Objective
1.2 Scope and limitation
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 System Operation of the Automatic Power
2.2 The Stand by Power Unit
2.3 Requirement for a Generator to be used on Change Over Switch
CHAPTER THREE
3.0 COMPONENT AND DESCRIPTION
3.1 Contactors
3.2 Contactors Mode of Operation
3.3 Circuit Breaker
CHAPTER FOUR
4.0 CIRCUIT DIAGRAM AND OPERATION
4.1 The NEPA Supply Unit
4.2 The Phase Selector Unit
4.3 The Generator Unit
4.4 Circuit Operation
4.5 Sequence of Operation
4.6 Testing and Result
4.7 Packaging
CHAPTER FIVE
5.0 OBSERVATION SUMMARY AND CONCLUSION
5.1 Observation
5.2 Summary
5.3 Suggestion
5.4 Conclusion
References
1.1 INTRODUCTION
Change over switch is a device used to switch off a power supply and subsequently switch on another power source. Basically it is aimed at switching on a more convenient power supply to the load. Since it switches on power to the load precaution has to be taken while choosing the type of change over switch. Also size, arcing control are put into consideration in the choice.
A good switch should be the one whose contact is made in such a way as to limit the arc formation by having no contact-bounce and by having contacts made of good conductive, corrosion resistance and wear resistance materials.
A good change over switch must have adequate insulation and must be so constructed and located as not to constitute a potential hazard.
A good change over switch should also have tight contacts so as to limit or eliminate the possibility of partial contacts at the contact point. The partial contact lead to over heating of the components and may lead to fire out break.
1.2 Aims and Objectives
Due to inconsistent supply of power, there is a growing need for an alternative source of power supply. This has led to heavy capital investment in a bid to curb power failure and ensure regular power supply for our industries, hospitals and homes. The problem of power failure can be checkmated with the use of standby generating set.
An Engineering author Tony Rudk Inn said in his book titled “Upgraded signal source with improved performance and reliability” that the cost and depreciation associated with breakdown vary from one application to the other, and in some cases, the user has little choice but to ensure that a stand-by unit is available to take over on event of failure of primary system.
If some of these big firms do not make provisions for stand-by power source, frustration could set in which may lead to the closure of business and thus throwing workers into unemployment. Also in the case of hospitals undergoing a surgical operation and the power supply suddenly goes off, the patient might loose his life due to power outage.
Furthermore, if the President of the country is making a nation wide broadcast and all of a sudden there is power failure in the transmitting station, it would be viewed as an attempt to sabotage the government ruling and some people must go for it.
Sequel to the rate at which more sophisticated electrical/electronics gadgets are being procured an installed in our homes, hospital and business premises, there is a justifiable need for a faster and more reliable change over system in an event of power outage.
In view of these considerations, this project is aimed at designing and constructing a workable automatic change-over switch with phase selector circuit which switches on the load from National Electric Power Authority (NEPA) to a generator when power comes back. Also when there is a phase failure in any of the NEPA phase carrying the load, the change-over switch will be changed to alternative phase.
1.3 SCOPE AND LIMITATION OF THE STUDY
The automatic change over switch is aimed to achieve the following automatic actions.
To start the generator
To change power to generator
To change back to NEPA
To change the generator
To change to alternative phase in case of phase failure.
The automatic change over unit can be operated in single or three phase-system. The automatic change over switch has the following advantages.
i. It minimizes damage to lives/equipment since it has its own monitoring system and its switching requires no human contact with the switch, thus eliminating human error.
ii. It reduces its change-over timing to the minimum due to its fast response to power outage.
iii. It maintains high quality of service through its fast and prompt response
iv. It avoids and reduces fuel consumption since the generator is switch off immediately NEPA supply is restored.
Moreover the size and capacity of the Unit will depend upon the load for which it will be used. The Unit is also portable, easy, convenient and safe to install.
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Single Phase Automatic Change Over Switch With Phase Selector:
A Single Phase Automatic Changeover Switch with Phase Selector is a device used to automatically switch between two power sources in a single-phase electrical system. This switch is commonly used in situations where a backup power source is available to ensure uninterrupted power supply. The phase selector allows you to choose between different phases when connecting to the power source.
Here’s a basic explanation of how such a system might work:
- Automatic Changeover Switch:
- This switch is responsible for automatically changing the power source from the main (utility) power to the backup power (generator or alternative source) and vice versa.
- It typically includes sensing mechanisms to detect the availability and quality of the main power supply.
- Phase Selector:
- In a single-phase system, there is usually only one phase, but in some cases (especially in industrial settings), there might be multiple phases available.
- The phase selector allows you to choose which phase to connect to. This can be useful in situations where there are multiple power sources or when there’s a need to balance the load across different phases.
- Control System:
- The control system manages the switching process based on predefined criteria. This can include voltage thresholds, frequency checks, and other parameters.
- It ensures a smooth transition between the main and backup power sources, minimizing downtime.
- Indicators and Alarms:
- The system may include indicators or alarms to inform users about the current power source, the status of the switch, and any potential issues.
- Visual indicators (LEDs) or audible alarms may be used for this purpose.
- Safety Features:
- Safety features, such as automatic cutoff in case of a fault or abnormal conditions, are often integrated into these systems.
- Installation and Wiring:
- Proper installation and wiring are critical for the reliable operation of the changeover switch. This includes ensuring correct connections, sizing of conductors, and compliance with electrical codes and standards.
- Manual Override:
- There might be provisions for manual override in case automatic switching is not desired or in case of system malfunction.
Before installing or operating such a system, it’s important to consult the manufacturer’s documentation and follow all safety guidelines. Additionally, compliance with local electrical codes and regulations is essential to ensure the safety and reliability of the setup. If you are not familiar with electrical systems, it is recommended to seek the assistance of a qualified electrician.