Summary
During my internship, I had responsibilities and works that I needed to do both in the field and in the office. As office works, I did research and wrote reports on the equipment used in the company, make electrical drawings about the systems used in the company and my internship project using AutoCad and SEE Electrical Cad, and learn the SAP program that the company uses for making work plan, trading operations, distribution of tasks, maintenance checks and etc. As fieldwork, I worked with electrical technicians to do as well as maintenance, repair, replacement and installation of electrical and electronic equipment when my supervisor wants.
1. INTRODUCTION
Çayeli Copper Enterprises is owned by First Quantum Minerals Ltd. which is established as a mining and metal company operating seven mines around the world. Çayeli Copper Industries, which produces copper and zinc ore since 1994, has 1.1 million tons of ore production and processing capacity per year [1]. Çayeli Copper Industries, which produces copper and zinc ore since 1994, has 1.1 million tons of ore production and processing capacity per year. With its high-tech electrical and automation systems and business health and safety policy, the company has the safe working environment. Cayeli Copper Works with a workforce of between 500 to 1000. It is one of Turkey's largest mine, is situated in Turkey's export champion list with 103 million dollars of exports [2].
2.PROJECT
I would like to start give an information my project, because most of the works are based on the project. The problem that the company has and they want me to solve is about having same volume of two speakers (MR90 Voice and MR90 SSS/EMS), it is shown Figure-1, at same time. The company wants that when someone pushes the emergency bottom, the volume of the MR90 SSS/EMS speaker needs to be higher for being awareness of emergency situation. They want me to draw electrical panel to implement the solution that I have found.
Figure 1- View of the speakers of MR90 Voice and MR90 SSS/EMS
To find a solution this project, I need to know how I can decrease or increase the volume of the speaker, how I can switch the one circuit into two parts and how I can draw electrical panel.
When I saw the project definition first time, I thought I should use logic gates that we have seen in Digital Design, however I didn’t know the real life electrical implementation of logic gates. Because of that, I started to investigate how to implement the logic gates into real life, and I found a device which is called relay. Thanks to relay, the circuit can be divided into two parts by an external signal with the help of the magnetic field, and we can isolate the circuit from each other. I have done research about what relay is, how it works and what the relay types are. The research report is added in additional files. After that, I have done researched about how speaker works and how I can arrange the volume of the speaker, then I have written a report about speaker which is added in additional files. I realized that both speaker and relay use magnetic field and force we have seen in Physics 2 and Electromagnetic Theory.
To take signal and run the relay, I have learned what PLC (Programmable Logic Circuit) and DCS (Distributed Control System) are and how they work. Then, I worked on PLC system of the company to find the tag name of signal that comes from emergency bottom. The tag of signal is DB91.DBX0.0/DB91.DBX1.7.
My supervisor and I decided to use two contact Electromagnetic Relay (EMR) and 220 Ohm Resistor for having higher volume from Emergency Speaker. After sketch drawing, I need to use software to draw the project as an Electrical Panel and to make it ready for implementation. I have learned how I can draw and read Electrical Panel by investigating Softstarter Panel Project (added to additional files) and other examples. I used SEE Electrical CAD, similar to Schematic as we used in Circuit 1,2 and Electronic 1, to draw my project as an Electrical Panel Project.
As a project solution explanation, I will use electrical drawings which 3 pages.
Figure 2-First Page of Project Solution
As it is shown Figure 2, The system representation starts from 220 VAC-24 VDC convertor and fuses. There is a two contact, one open and other one closed, Electromagnetic Relay whose tag name is A3.0 that isolates the circuit and makes the switching operation in column 3. In column 9, There are reference numbers that indicate where cables come from and where they go. For example, GND (Ground) is coming from ninth column of first page as it is shown 100.9, and the number at the end of the cable which 200.9 means it goes to ninth column of the second page.
Figure 3-Second Page of Project Solution
Output (2) represents the circuit when the relay is not activated, and Output (1) represents the circuit when relay is activated. The speaker, in sixth column, symbolizes the voice speaker (MR90 voice). As it is shown Figure-3 in column 3, there is a 220 Ohm resistor to make the volume lower than Emergency Speaker (MR90 SSS/EMS).
Figure 4-Third Page of Project Solution
The cable in first column demonstrates emergency signal whose tag name is DB91.DBX0.0/DB91.DBX1.7 that is written in PLC. Q3.0 represents the electromagnetic part of relay. After activating of this part by 24V emergency signal that comes from Emergency bottom, the contacts (in Figure-2) will be switched, then the current will go through on the circuit (Output 1) with resistor. Thanks to activating of relay, the volume of the MR90 voice will be decreased.
The breakdown of the DC motor of the human elevator, which is connected to the building that is called the shaft, as it is shown in Figure 5-6, that helps workers to transport to underground. This fault gave me the opportunity to observe the DC motors with brushes ( fotoğraf koyulacak). Before working on the DC motor, I did some research to get more information about DC motors with the supervisor’s advice. The research is added to additional files. I knew what DC motors were used for, but I learned about the internal structure of DC motors and how it works in this research and observing process. The resistance of the motor is measured by Multimeter, as we used in Circuit 1,2, to determine whether the motor was operating efficiently and whether there was any combustion in the motor. After the measurements, it was decided to change the motor brushes.
Figure 7-Floatation systems for enrichment the copper
The level meter used to measure the level of lime tanks the company used to enrich copper was broken down [3]. I did some research to have more information about level transmitters (added to additional files). Radar Level Transmitter was decided to use in order to have more accurate result with my contributions. It uses radar pulses; the flight time of reflected radar pulses is related with level. It works based on speed-time relation as we have learnt in Physics 1. I was involved in changing the measuring device and performing the calibration.
Figure 8- Radar Level Transmitter
There is a system in the company that allows the waste water generated after some operations to be disposed of without harming the environment. I made an electrical technical drawing using AutoCAD to activate the valve that measures and controls the effluent flow in this system after observing the MOXA (Figure 10) and terminal boxes (Figure 9) in the field. The AutoCad drawing is added to additional files.
Figure 10-MOXA
Furthermore, I had a chance to observe and study on Communication Protocols that used in company. Before examining the communication protocols, I did research on Digital-Analog I/O and Communication Protocols, they are added in additional files. I mostly studied on HART (Highway Addressable Remote Transducer) which uses Bell 202 Frequency Shifting. The shifting or modulation property was covered in Signal and Systems. What I was familiar that Digital-Analog I/O and frequency modulation. On the other hand, Communication Protocols were things that I didn’t know. Also, there are many Servo Motors and their drivers that used for pumps and high-power air conditioners in the company. Thanks to having these motors, I had an opportunity to observe and get information about them that will help me during Electric Machines course.
Lastly, I have studied all P&ID instruments with my supervisor’s advice. I did research wrote papers about Density Transmitters, PH Transmitters and Flowmeters, all studies are added in additional files. I have learned how P&ID systems and instruments work, that might help me in Feedback and Control Systems course. Also, I have worked on Circuit Breakers and Separators in high voltage systems, that might be helpful to me for fourth year courses.
3. CONCLUSIONS
As an intern, I helped technicians as work force, I found a solution to the problem in the company as a project and I tried to help by presenting ideas on some topics.
One of the most important thing that this internship contributions to me is that applying the rules of occupational health and safety while we are working on the field. I have gained some experience as to what security precautions we should take and what isolations we should do when working in the field. When I worked with the technicians, I experienced how we could use the theoretical knowledge we learned. I examined the PLC and DCS found in the company and learned how they simply worked and coded. Thanks to my supervisor’s experience in the automation engineering, I had a great deal of knowledge about automation systems and instruments and I have learnt how to read and explain the P&ID diagram. This gives me great opportunity to have a perspective about Automation Engineering. At the end of the internship, I got a first experience in professional business presentation thanks to the presentation I made to the engineers and managers. Apart from those, some of the things that make this internship unique for me are the feeling of working in the business environment and producing something, meeting new friends and people.