AUTOMATION AND CONTROL TRADE 19 TAR SANDS

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Sibyl Robertson
5 years ago
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1 AUTOMATION AND CONTROL TRADE 19 TAR SANDS Page 1

2 General With this challenge, we will assess your: a) ability to analyze technical data. b) quality of wiring. c) capacity to implement an automatic process. d) troubleshooting techniques. e) abilities for error detection Step A: Wiring an automated process within a panel As a technician, you should have the ability to completely wire a system and make the necessary modifications. We will assess the quality of your manual work, and the precision with which you will reference the drawings provided Step B: Programming the automated process Step C: Troubleshooting The programmable controller used in this challenge will be provided by you, the competitor. The PLC matches the specifications given in the Scope document. You are provided with a description of a process, and you must program the automated process. The system must be functional, and adhere to the drawings and instructions. Your ability to detect and solve problems will be assessed. 3.1 General Description The automated system you will be creating is a part of the process that might be used in extracting oil from the Tar Sands in Northern Alberta. The purpose of the part of the system you will be creating is to measure batches of 2500 Kg. of Tar Sand for further processing. This system consists of: - Tar Sand conveyor driven by motor #1 (MTR#1). - Tar Sand conveyor driven by motor #2 (MTR#2). - Mixer motor driven by (MTR#3) - Tar Sand bin, outlet for this is controlled by a solenoid operated valve, and a weight switch operated at 2500 Kg (simulated by a 2 position on/off switch) For the purpose of this exercise we will assume that there is a constant supply of Tar Sand on the infeed conveyor, and the Tar Sand, once it is dumped from the bin, will enter another process that will continue further extraction. Page 2

3 Automatic Mode Mode 1 When the process is in automatic Mode I it will fill the bin up to a weight of 2500 Kg. The conveyers will stop and the bin will empty through the solenoid controlled dump gate. At the completion of the cycle the process is ready to begin again. The starting position of the process is: - Conveyor #1 (MTR #1) is stopped - Conveyor #2 (MTR #2) is stopped - Tar sand bin ready to be filled, Solenoid Valve closed To start the process turn the Mode I/Mode II selector to the Mode I position and the Hand-Off- Auto selector to the Auto position. To start the machine the green Process Start button, located in the #2 two-button station mounted on the wall, is pressed and the automatic process begins. Conveyor #1 (MTR #1) and Conveyor #2 (MTR #2) must run in sequence as follows: 1. Conveyor #2 (MTR #2) starts in the forward direction and must run for five (5) seconds before Conveyor #1 can start. A red mounted in the front of the control panel will illuminate indicating that Conveyor #2 is running. 2. Conveyor #1 (MTR #1) starts in the forward direction. A red mounted in the front of the control panel will illuminate indicating that Conveyor #1 is running. 3. Once the weight operated switch (simulated by a 2 position ON/OFF selector switch) changes state indicating that 2500 Kg. of Tar Sand has been loaded into the bin, Conveyors #1 & #2 will turn off. A red indicator will illuminate when the weight operated switch changes state. The selector switch that simulates the operation of the weight operated switch and the red indicator are located in the two position station (WS1) on the wall adjacent to the control panel. 4. The Solenoid valve (S1) will energize for 10 seconds and release all Tar Sand from the bin. A red indicating mounted in the front of the control panel will illuminate when the Solenoid Valve is energized. The process now restarts and continues to cycle through the above steps as long as the selector switches remain as stated. When the Process STOP button, located in the #2 two-button station mounted on the wall, is pressed the process shall continue to operate until it has finished its cycle. Mode II Page 3

4 The purpose of Mode II is to mix the batch of Tar Sand after loading the correct amount into the bin. The mixer must complete six revolutions to mix the batch properly. The revolutions are measured using a limit switch, which will pulse six times to verify the revolutions. The starting position of the process is: - Conveyor #1 (MTR #1) is stopped - Conveyor #2 (MTR #2) is stopped - Mixer motor (MTR #3) is de-energized - Tar sand bin ready to be filled, Solenoid Valve closed To start the process turn the Mode I/Mode II selector to the Mode II position and the Hand-Off- Auto selector to the Auto position. To start the machine the green Process Start button, located in the #2 two-button station mounted on the wall, is pressed and the automatic process begins. Conveyor #1 (MTR #1) and Conveyor #2 (MTR #2) must run in sequence as follows: 1. Conveyor #2 (MTR #2) starts in the forward direction and must run for five (5) seconds before Conveyor #1 can start. A red mounted in the front of the control panel will illuminate indicating that Conveyor #2 is running. 2. Conveyor #1 (MTR #1) starts in the forward direction. A red mounted in the front of the control panel will illuminate indicating that Conveyor #1 is running. 3. Once the weight operated switch (simulated by a 2 position ON/OFF selector switch) changes state indicating that 2500 Kg. of Tar Sand has been loaded into the bin Conveyor #1 & #2 will turn off. A red indicator will illuminate when the weight operated switch changes state. The selector switch that simulates the operation of the weight operated switch and the red indicator are located in the two position station #1 (WS1) on the wall adjacent to the control panel. 4. Mixer (MTR #3) starts to stir the Tar Sand and runs for six (6) pulses of the Limit Switch (LS1). The Limit Switch (LS1) is on the bin in such a manner that it is operated once for each revolution of the Mixer. Once the Limit Switch counts six (6) the Mixer will turn off. A red indicating mounted in the front of the control panel will illuminate when the Mixer is running. 5. After the mixing is complete the Solenoid valve (S1) will energize for 10 seconds and release all Tar Sand. A red indicating mounted in the front of the control panel will illuminate when the Solenoid Valve is energized. The process now restarts and continues to cycle through the above steps as long as the selector switches remain as stated. When the Process STOP button, located in the #2 two-button station mounted on the wall, is pressed the process shall continue to operate until it has finished its cycle. Page 4

5 Manual Mode The system is changed to Manual Mode by moving the Hand-Off-Auto selector switch to the Hand position. When the process is in manual control mode Conveyor Motors #1 and #2 may be controlled manually by mean of a selector (forward-off- reverse) switch mounted on the wall in three-button station #3. Three-button station #3 consists of three elements. At the top of the station is a red indicator that flashes at an interval of 1 second on 1 second off as long as the Hand-Off-Auto selector is in the Hand or Manual control mode. In the second position on the station is a threeposition,spring return, (forward-off-reverse) selector switch which controls Conveyor #1 in both forward and reverse directions, In the third position on the station is a three-position, spring return,(forward-off-reverse) selector switch which controls Conveyor #2 in both forward and reverse directions. Emergency mode The Emergency Stop button is to be connected to and control the MCR relay. The purpose of the MCR relay is to shut down all power to the outputs of the PLC but the power to the logic of the PLC should remain energized. When an Emergency Stop button is pressed all motors will stop immediately and the solenoid valve will close or remain closed. Once the Emergency Stop button is reset the machine must not start again until it is put into Manual Mode and then returned to Automatic Mode. 3.2 Process Diagram Page 5

6 3.4 Input and outputs technical details Inputs The system is equipped with a general emergency stop button. It s main contact (normally closed) cuts off power to the PLC outputs, including those for the motors. The emergency stop button is mounted in the front of the control panel, and has to be connected on the first PLC input. You have to find the most economical way to wire this information to the PLC. The automatic sequence is not reinitialized after an emergency stop; machine operator intervention is necessary to manually reset by selecting Manual Mode and then return to Automatic Mode on the Master control selector switch located on the control panel. Outputs The Conveyor #1 is driven in both directions by Motor #1 which is controlled by Starter K1F and K1R. The Conveyor #2 is driven in both directions by Motor #2 which is controlled by Starter K2F and K2R. Solenoid valve #1 controls the control valve on the Bin and is controlled by relay K3 (Note use a 3P contactor and wire for single phase) The Mixer is driven in one direction only by Motor #3 which is controlled by Starter K4 Starters K1F, K1R, K2F, and K2R will provide a confirmation of run status to an indicator by the auxiliary contact on the contactor. The following tables are a recommended assignment of the inputs and outputs for your programmable control. As controllers vary in how they are connected and function, you must check your particular PLC to see if these assignments are suitable. Inputs detail Symbol PLC inputs Assignments Information supplied at state «1» Emergency stop ES In0 Emergency stop button not operated Auto mode AUTO In1 Auto mode selected Manual MAN In2 Manual mode selected Mode I Mode I In3 Mode I selected Mode II Mode II In4 Mode II selected Limit Switch 1 LS1 In5 Mixer pulse Weight Switch 1 WS1 In6 Tar Sand Weight Process Start PStart In7 Button pressed, start process Process Stop PStop In8 Button not operated Page 6

7 Conveyor Motor #1 Selector Fwd Conveyor Motor #1 Selector Rev Conveyor Motor#2 Selector Fwd Conveyor Motor#2 Selector Rev SEL MTR #1 FWD SEL MTR#1 REV SEL MTR#2 FWD SEL MTR#2 REV In9 In10 In11 In12 Conveyor Motor #1 forward Conveyor Motor #1 reverse Conveyor Motor #2 forward Conveyor Motor #2 reverse Outputs detail Symbol PLC outputs Action at state «1» Assignments Conveyor Motor #1 K1F Out0 Motor #1 starts forward Conveyor Motor #1 K1R Out1 Motor #1 starts reverse Conveyor Motor #2 K2F Out2 Motor #2 starts forward Conveyor Motor #2 K2R Out3 Motor #2 starts reverse Bin Solenoid Valve K3 Out4 Bin solenoid valve open Mixer Motor #3 K4 Out5 Motor #3 starts Conveyor #1 Indicator CON #1 Out6 Conveyor #1 Indicator illuminates Conveyor #2 Indicator CON #2 Out7 Conveyor #2 Indicator illuminates Mixer Motor #3 Indicator MIX #3 Out8 Mixer Motor #3 Indicator illuminates Solenoid Valve Indicator S1 Out9 Solenoid Valve Indicator illuminates Weight Switch Indicator WS1 Out10 Weight Switch Indicator illuminates Manual Operation Flashing indicator FLASHER Out11 Flashes to indicate that machine is in manual Page 7

SPECIFICATIONS NB SKILLS TRADE 19 AUTOMATION AND CONTROL

SPECIFICATIONS NB SKILLS TRADE 19 AUTOMATION AND CONTROL NBCC/CCNB 2016 1.1 SCENARIO. 3 1..1 GENERAL.. 3 1..2 STEP A: WIRING AN AUTOMATED PROCESS WITHIN A PANEL 3 1..3 STEP B: PROGRAMMING THE AUTOMATED