Unit - 6
Industrial Electrical System Automation
Q1) What is PLC?
A1) PLC stands for Programmable Logic Controller.
PLC is an industrial computer used to control a specific process, machine system, or sometimes even an entire production line.
PLC is the combination of both Hardware and Software. PLC consists of many inputs and outputs terminal in which we can connect various inputs and outputs.
Users can prepare a logical program and download it into the PLC. A PLC monitors the status of switches and sensors using input terminals and based on this status they will give the command to the output devices through the output terminals.
Q2) What are the different components of PLC?
A2) These are the important components of the PLC system:
Q3) What are the various applications of PLC?
A3) PLC is used in almost all types of industrial applications.
Q4) What is the role of PLC in Automation?
A4) In the automation, PLC is playing a significant role in controlling and monitoring industrial applications.
It has both hardware and software.
This controller device can be executed or operated by automatically and manually. For its operation, it consumes additional manpower, time, utility, and accurate operation in the system.
It is useful for increasing the reliability and stability of the system. It performs precise operations within very less time. This is one of the reasons, today, PLC is widely used in the industry.
Q5) What are the advantages of the PLC over the Hardware Relay?
A5) The following are the advantages of PLC over the hardware relay.
Q6) Explain the functions of PLC.
A6) The functions of the PLC are,
Q7) What is the major area of applications of PLC?
A7) PLC has multiple applications in various sectors.
PLC is mostly used for commercial and educational purposes.
Q8) What are the main advantages of PLC?
A8) There are various advantages of PLC.
For these advantages, PLC is replacing hardware relay and it is industrially accepted.
Q9) What are the disadvantages of PLC?
A9) Apart from various advantages, there are a few disadvantages.
Q10) What is role of I/O modules?
A10) Electronic plug-in units used for interfacing the i/p and o/p device in the machine or process to be controlled.
I/P module receives data from i/p devices (Pushbutton, Switches, Transmitters) and send it to processor. The O/P module receives data from processor and send it to output device (Relay, Valves).
Q11) What are Features and Application of SCADA
A11) Features: The common features of SCADA include Dynamic process mimic, Trends, Alarm, Connectivity with hardware, Recipe management etc.
Applications: SCADA systems has many applications right from industrial automation, power distribution to water management.
Q12) Explain the main function of each of the following major components of a PLC:
A12)
The processor (CPU) is the “brain” of the PLC. A typical processor usually consists of a micro-processor for implementing the logic and controlling the communications among the modules. The processor requires memory for storing the results of the logical operations performed by the microprocessor.
The I/O system forms the interface by which field devices are connected to the controller. The purpose of this interface is to condition the various signals received from or sent to external field devices.
Input devices such as pushbuttons, limit switches, and sensors are hardwired to the input terminals. Output devices such as small motors, motor starters, solenoid valves, and indicator lights are hardwired to the output terminals.
A programming device is used to enter the desired program into the memory of the processor. The program can be entered using relay ladder logic, which is one of the most popular programming languages. Instead of words, ladder logic programming language uses graphic symbols that show their intended outcome. A program in ladder logic is similar to a schematic for a relay control circuit.
The power supply: DC power to other modules that plug into the rack. For large PLC systems, this power supply does not normally supply power to the field devices. With larger systems, power to field devices is provided by external alternating current (AC) or direct current (DC) supplies. For some small micro PLC systems, the power supply may be used to power field devices.
Q13) What are the two most common types of PLC programming devices?
A13)
Q14) What is the standard programming language used with PLCs?
A14) Relay ladder logic (RLL) is the standard programming language used with PLCs. Its origin is based on electromechanical relay control. The relay ladder logic program graphically represents rungs of contacts, coils, and special instruction blocks.
RLL was originally designed for easy use and understanding for its users and has been modified to keep up with the increasing demands of industry’s control needs.
Q15) Define Ladder Logic
A15) Ladder Logic is the oldest programming language for PLCs. Suitable for expressing combinatorial logic. The main ladder logic symbols represent elements. Contact Break Create a contact relay coil.
Q16) Draw different Ladder Logic Symbol
A16)
Q17) Write the advantages of Process Automation.
A17) 1. Operational Efficiency – BPA can increase efficiency by reducing process-related work and reducing salary costs by limiting the need for additional personnel as operations grow. I can do it.
2. Productivity – Speed up your process so you can get things done faster and with fewer iterations.
3. Morale – Relieves workers' monotony and improves employee experience and customer experience. This will further improve the employee experience. “The more time employees spend on the interesting and rewarding aspects of their work, the more productive and satisfying they are, and the more employee retention rates they have,” according to a CIO report.
4. Governance and Management – Improve compliance to prevent businesses from violating regulations and incurring large fines and fees.
5. Cost Reduction – By using time efficiently, companies can choose to increase production without expanding their workforce or reduce salary costs to maintain the same level of production.
6. Employee Assignment – Employees can reassign to jobs that are more suited to their talents. Employees are more satisfied with their work and employers can maximize the benefits of their individual talents.
7. Reduced Human Error – Employee time is not wasted on repetitive low-level work, significantly reducing human data entry and insight errors and improving efficiency.
8. Collaboration – Track project processes, update teams, send reminders, and perform other functions that make collaboration easier and more organized. In addition, BPA relieves employee frustration and frees up time for collaboration. This tends to speed things up, help solve problems, and drive innovation.
9. Improve Insights – Improve your leadership ability to track business process completion and understand process steps. This makes it easier to improve the process and get faster and better business results. BPA also allows readers to dig deeper and analyze more new data for more insight. In addition, standardizing business processes can ensure fairness and eliminate biases that can distort insights.
10. Increased Availability – Make services for employees and customers available more often than if you were also responsible for other manual tasks.
Q18) Write short notes on Panel Metering.
A18) A metering panel is a type of control panel that is highly needed for home and industrial use to measure power consumption and power consumption rate. These metering panels are the best equipment that can be easily installed and conveniently used in power consumption processes. The weighing panels in these apartments are very easy to install and are equipped with excellent anemometers and galvanometers for calculating current input and output voltage amplitudes.
Panel metering is the key to understanding the energy consumption of homes, buildings and facilities. This is often done by measuring the entire panel at the source or by measuring individual circuits for more sophisticated results (branch circuit monitoring).
Panel meters provide a variety of features such as data logging, internal memory, usage time, and power quality. In addition, the panel meter has various communication options that allow you to collect data remotely. This allows remote easy remote access to a set of power and energy readings for detailed reporting.
Panel metering options include single-phase and three-phase meters, and multi-circuit power meters. All of our measurement options can communicate via a variety of protocols.
Q19) List four criteria by which PLCs are categorized.
A19) 1. Functionality.
2. Number of inputs and outputs.
3. Cost.
4. Physical size.
Q20) List five factors affecting the memory size needed for a particular PLC installation.
A20) 1. Number of I/O points used
2. Size of control program
3. Data-collecting requirements
4. Supervisory functions required
5. Future expansion