Construction Electrician Level 3

Transcription

1 Level 3 Rev. September 2008

2 Unit: C1 Electrical Code III Level: Three Duration: 60 hours Theory: Practical: 60 hours 0 hours Overview: This unit of instruction is designed to provide the Electrician apprentice with knowledge and understanding of the Canadian Electrical Code. On satisfactory completion, the apprentice-learner will be able to describe contract documents and drawings, busways, trolley busways, lightning protection, lighting, data infrastructure, harmonics, describe and calculate installation of conductors in raceways, free air and underground, main service requirements for main services and feeder subpanels (building calculations three phase plus single), installation of transformers, motors (single and group motors), in addition to reviewing single phase voltage drop, three phase voltage drop, continuous loading, conductor derating and system voltages and will apply code regulations where applicable. Percent of Objectives and Content: Unit Mark (%) 1. Describe contract documents and drawings. 7% a. Identify contract documents b. Identify layout of specifications c. Identify the drawings in a typical construction drawing set d. Read site plans to determine the locations of specific items 2. Describe Busways. 2% a. State the benefits of using busways Identify common applications of busways List the components of busways Describe various support systems. 3. Describe trolley busways. 2% a. Identify features of a trolley busway installation b. Select components to support cord drops 4. Describe lightning protection. 3% a. Describe the lightning process b. Identify the requirements for protecting a building c. List lightning safety rules 5. Describe lighting. 5% a. List the important considerations in lamp selection for lighting systems b. Select illuminance values for site lighting 1 Rev. September 2008

3 c. Compute the power limit and power demand for site lighting d. Locate luminaires (fixtures) for site lighting e. List control options for lighting systems 6. Describe harmonics. 5% a. Describe a harmonic b. Discuss the problems concerning harmonics c. Identify the characteristics of different harmonics d. Perform a test to determine whether harmonic problems exist e. Discuss the methods of dealing with harmonic problems 7. Describe and calculate installation of conductors in raceways, free air and underground. a. Single raceways, MI, Al sheath, Teck, AC b. Parallel raceways, MI, Al sheath, Teck, AC. c. Section Describe and calculate main service requirements for main services and feeder sub-panels (Building calculations single phase and three phase). a. Small industrial building b. Schools, Hospitals, Motels, Hotels 22% 13% 9. Describe and calculate installation of transformers and capacitors. 17% a. Transformers single and three phase installations - all types b. Primary and secondary O.C.P. conductors, bonding and grounding 10. Describe the installation of motors (single motors + groups of motors). 16% a. Single phase AC (individual) b. Three phase AC (individual) c. DC (individual) d. Various duty cycles continuous, intermitting, varying, periodic, short-time 11. Describe for review purposes single phase voltage drop, three phase voltage drop, continuous loading, conductor derating, and system voltages. 8% *** 2 Rev. September 2008

4 Unit: C2 Three Phase Theory and Transformers Level: Three Duration: 90 hours Theory: Practical: 90 hours 0 hours Overview: Upon successful completion of this course, the apprentice will have the knowledge of the three-phase systems including wye circuits, delta circuits, power factor correction, methods of three-phase power measurement. The apprentice will also gain a knowledge of transformers including operating principals, ratings and ratios, polarities, cooling methods, PCB hazards, tap setting, single phase transformer connection, % impedance, paralleling, three phase transformer connections, troubleshooting and protection, and current transformers and potential as well as power quality, power factor correction, filtering and surge suppression devices. Percent of Objectives and Content: Unit Mark (%) 1. Three Phase Theory. 28% a. Describe by the use of a phasor diagram the relationship between phase voltage and line voltage in a wye connected source. b. Describe by the use of phasor diagram the relationship between phase voltage and line voltage in a delta connected source. c. Describe and verify by connection, the relationship between phase and line for a wye system. d. Describe and verify by connection, the relationship between phase and line for a delta system (balanced). e. Describe the phase relationship between phase currents and phase voltages in a wye connected system at unity, and other than unity power factor (balanced and unbalanced) by the use of a phasor diagram. f. Describe the importance of neutral conductor on an unbalanced Wye system. g. Describe the phase relationship between phase currents and phase voltages in a delta connected system at unity and other than unity power factor (balanced or unbalanced) by the use of a phasor diagram. h. Calculate three-phase true power, apparent power and reactive power in balanced and unbalanced systems. i. Describe overall power factor as it applies to three phase systems. j. Describe how capacitors should be connected to a three-phase system. k. Perform power factor correction calculations and verify. l. Calculate and verify power measurement single phase two wattmeter method three wattmeter method m. Verify three-phase power, apparent power and reactive power 3 Rev. September 2008

5 2. Transformers. 61% a. Describe the purposes of a transformer. b. Describe the basic components of a transformer and the nameplate information c. (conservator, bushings, pressure relief device, breather [types-activated alumina, silica gel, drycol condenser], gas relay, gauges and sensors). d. Describe primary and secondary of a transformer. e. Describe the difference between a step-up and a step-down transformer. f. Describe the standard terminal and winding identification. g. Describe transformers action. h. Describe the operation of a transformer as load is added. i. Describe the losses that occur in a transformer. j. Calculate the efficiency of transformers. k. Describe the operation and demonstrate connections for auto transformers, isolating transformers and grounding transformers). l. Describe how transformers are rated and sized. m. Describe and solve problems involving transformers in terms of voltage, turns and current ratios. n. Describe the reason why transformers are rated in voltage and volt-amps. o. Describe the possible effects of operating a transformer at above its rated voltage. p. Describe the difference between the high voltage and the low voltage windings of a transformer (30 degree shift for Delta Wye, 60 degree Wye-Wye). q. Calculate the rated primary and secondary currents of a transformer from nameplate data. r. Describe a properly rated transformer for a specified load. s. Describe the difference between subtractive and additive terminal markings. t. Describe the various methods of cooling for distribution & Power transformers and the liquids used (air, water, oil, forced & natural). u. Describe the hazards of PCBs as related to transformers. v. Describe how to set a tap changer to increase and decrease secondary voltage levels (auto and manual). w. Describe tap changers and 3 phase regulators and their applications (on load in separate compartment, off load in main tank. x. Describe out of step condition when runing tap changers in parallel. y. Describe the purpose of % impedance stated on the nameplate for parallel operation. z. Describe the maximum fault current from nameplate data. aa. Describe the conditions to be met before operating two transformers in parallel. bb. Describe the expected secondary voltage by the use of a phasor diagram. cc. Describe the connections required, given the nameplate information, for supply voltage, and required load voltage for single and three phase transformers. dd. Draw schematics and wiring diagrams for single and three phase transformer connections. ee. Measure and compare primary and secondary voltages. ff. Describe the purposes of instrument transformers. gg. Describe the primary and secondary circuit connections for current transformers (CTs) and potential transformers (PTs). hh. Describe why a shorting device must be provided on the secondary of a current transformer. ii. Describe and give examples of commonly used ratings of instrument transformers. jj. Describe the connection of instrument transformers and how to put it into a circuit to determine the voltage and the current. kk. Describe bump recorders and the information it provides. ll. Connect two transformers in parallel and observe how they share the load. mm. Connect the windings of a transformer for series or parallel operation. nn. Connect a single phase transformer, single and dual voltages. oo. Connect three phase transformer banks. 4 Rev. September 2008

6 3. Power Quality. 11% a. Identify the characteristics of a sustained, temporary and momentary power interruption. b. Identify the characteristics of voltage sag, voltage swell, over and under voltage condition, voltage fluctuation and voltage transient. c. Describe the operation of different types of UPS (uninterruptible power supplies) systems Standby Generator Battery Charger/Battery Bank Electronic Converters d. Describe surge suppression and how it is applied to transmission lines, primary distribution centers and secondary circuits Lightning Arrestors MOV s (metal oxide varistors) e. Describe the effects of linear and non-linear loads on the electrical distribution system. f. List the frequency of different order harmonics. g. Identify the electrical effects that are caused by negative, positive and zero sequence harmonics to transformers, circuit breakers and neutral conductors. h. Describe the effects of harmonic currents on motors, capacitors and sensitive electronic equipment. i. Describe displacement power factor, THD (total harmonic distortion) and transformer K Rating *** 5 Rev. September 2008

7 Unit: C3 Electronic Concepts II Level: Three Duration: 45 hours Theory: Practical: 21 hours 24 hours Overview: This unit of instruction is designed to provide the Electrician apprentice with additional knowledge and understanding of electronic concept applications. Percent of Objectives and Content: Unit Mark (%) 1. Review of Electronic Concepts. 11% a. Describe the relationship between heat and conductivity. b. Describe several methods used to improve conductivity. c. Describe, draw and label an illustration to explain what happens at the junction of an unbiased "P" and "N" type semi-conductor material. d. Describe and use an illustration to explain what happens when the P-N junction is forward, reverse and over biased. e. Describe and draw the symbol for a P-N junction diode and identify the terminals. f. Describe and discuss the term Peak Inverse Voltage (P.I.V.) g. Describe and test a diode with an ohmmeter. h. Describe the operation of the half-wave, and full wave rectifier circuits using either centre tapped transformers or a bridge configuration. i. Describe and calculate peak current, peak voltage, average current, average voltage, R.M.S. current and R.M.S. voltage for all types of rectification circuits connected to a given load. j. Describe and calculate the output frequency of each of the above rectifiers. k. Describe the purpose of a filter circuit. l. Describe the operation of a capacitor, inductor and resistor type filter circuit. m. Describe percentage ripple. n. Identify the schematic symbol and terminal connections of a SCR. o. Describe the operation of a SCR in a DC circuit. p. Describe the operation of a SCR in an AC circuit. q. Describe the terms phase shifting, conduction angle and communication with reference to a SCR. r. Describe the test method used to test a SCR with an ohmmeter. s. Connect a SCR to control a DC circuit. t. Connect a SCR to control a single phase AC circuit. u. Describe common applications for SCR s in DC and AC circuits. v. Identify the schematic symbol and terminal connections of a Triac. w. Describe the operation of a Triac in an AC circuit. 6 Rev. September 2008

8 2. Transistors. 18% a. Describe the basic operating principles of the transistor including the linear, saturation and cut-off. b. Describe and draw the symbol for a PNP and NPN transistor and label the terminals. c. Describe and discuss basis transistor characteristics and characteristic curves. d. Describe the basic construction of various transistors (case configuration, terminal identification). e. Describe and test a transistor both in and out of a circuit. f. Describe the following transistor characteristics and symbols operating point current gain voltage gain load lines g. Describe the purpose of the heat sink. h. Describe various types of other transistors (e.g., JFET and MOSFET circuits, insulated gate bi-polar transistors) 3. Amplifiers. 18% a. Describe and compare the basic characteristics of a common-emitter, commonbase, and common-collector transistor amplifier. b. Describe biasing methods. c. Describe coupling methods. d. Describe and analyze transistor bias circuits for the operating point. e. Describe and analyze transistor circuits for voltage and current gain. f. Describe and discuss voltage phase inversion in the three basic amplifier circuits. 4. Basic Electronics (Lab). a. Use multimeter, transistor tester for testing diode and transistor characteristics. 14% b. Use oscilloscope, meter and signal generator to demonstrate common emitter 14% and common collector amplifier characteristics (biasing, gain, saturation and cutoff regions). c. Use test equipment to analyze the operation of SCR and triac phase control. 13% d. Measure the ripple and the frequency of a filtered DC power supply output waveform with an oscilloscope. 12% *** 7 Rev. September 2008

9 Unit: C4 PLCs/Control Systems (includes Mathematics) Level: Three Duration: 90 hours Theory: Practical: 65 hours 25 hours Overview: This unit of instruction is designed to provide the Construction Electrician apprentice with complex knowledge and understanding of microprocessor-based control and monitoring systems (PLCs). The unit is intended to supplement the information taught in print reading, electrical code and electrical concepts. Percent of Objectives and Content: Unit Mark (%) 1. Identify the basic components of fixed and modular Programmable Logic Controllers. a. Processor unit b. I / O section Fixed and remote c. Power supplies d. Programming devices e. Numbering systems 2% 2. Describe the function(s) of the main components of a PLC. 2% a. Processor unit b. I / O modules c. Power supplies d. Programming device 3. Program basic ladder logic using discrete inputs and outputs. 2% a. Interpret basic ladder logic Examine on and examine off contacts Internal and external outputs Time on and time off timers Count up and count down counters b. Field and internal addressing systems 4. Describe troubleshooting methods for PLC controlled systems. 2% a. LED indicators b. Search functions c. Forcing functions d. Voltmeter testing Power supplies I / O modules 8 Rev. September 2008

10 5. Describe safe programming and wiring practices for PLC controlled systems. 2% a. Master control relays b. Emergency stop stations c. Over current protection d. Bonding and shielding e. Processor security (e.g., key lock and software) f. Proper procedures for using force functions g. Program documentation h. Processor scan time i. Contact nesting 6. Describe the functions and use of specialty modules. 2% a. Analog input and output modules b. Communication modules c. Numerical modules 7. Describe memory storage systems, CPU and its main components as it pertains to PLC's and microprocessors. 8. Apply basic principles/functions of programmable logic, including discrete, inputs/outputs, and counters and timers. 9. Describe the function & operation & application of motor control with use of pilot devices. a. push buttons b. float switches c. temp switches d. flow switches e. pressure switches f. limit switches g. selector switches 10. Describe, design & demonstrate motor control schematic diagrams with all applicable pilot devices. 11. Describe, design & demonstrate motor control circuits and application by use of sensing devices. a. proximity detectors (e.g., inductive, capacitive, and magnetic) b. photo detectors 2% 24% 18% 8% 8% 12. Describe troubleshooting methods for PLC controlled systems. 18% a. explain the difference between across the line and reduced voltage starting methods b. explain the various methods Wye-start, Delta-run Part winding starts Resistive starts Reactive starts wound rotor motors 13. Describe & demonstrate variable frequency drive and soft start controllers. 7% 14. Describe manual and automatic control for synchronous motors. 3% 9 Rev. September 2008

11 Unit: C5 Breakers, Fuses, Disconnects and Bus Level: Three Duration: 20 hours Theory: Practical: 20 hours 0 hours Overview: This unit of instruction is designed to provide the Electrician apprentice with introductory knowledge and understanding of breakers, fuses, disconnects and bus. Percent of Objectives and Content: Unit Mark (%) 1. Breaker Fundamentals. 25% a. Describe different types of breakers (low voltage and high voltage) and common characteristics. b. Describe arc, and arc-extinguishing media: gas, bulk oil, magna blast, minimum oil, air blast, vacuum 2. ARC Extinguishing Media (Gas). 5% a. Describe gas (sulfur hexafluoride [SF6] and carbon tetrafluoride [CF4]) properties and their requirements for safe handling, recovery (vacuum) and storage. b. Describe personal hazards associated with maintaining gas breakers. High pressure gases SF6, CF4 and arc extinguishing byproducts 3. ARC Extinguishing Media (Air Blast). 5% a. Describe hazards/safety precautions associated with the use of compressed air. b. Describe high-pressure air systems, including air-drying equipment 4. ARC Extinguishing Media (Magnetic-Air Breakers/Magna Blast). 3% a. Describe arc chutes, pole pieces and blow out coils including asbestos hazards 5. ARC Extinguishing Media (Oil Filled Breakers). 10% a. Describe insulating oil properties/characteristics, safe handling procedure, and safe storage requirements (for example) Voltesso 35, ASEA 43 b. Describe oil filtration/recovery systems. c. Describe personal and environmental hazards associated with maintaining oil breakers PCB levels Airborne oil vapour Release to the environment 10 Rev. September 2008

12 6. ARC Extinguishing Media (Vacuum Breakers). 2% a. Describe safety precautions for handling vacuum bottles (radiation warning). b. Describe how an arc is extinguished in a vacuum 7. Breaker Operating Mechanisms. 20% a. Describe stored energy operating mechanisms (springs) and their hazards. b. Describe solenoid operating mechanisms and their hazards. c. Describe hydraulic operating mechanisms and their hazards. d. Describe high pressure air operating mechanisms and their hazards. e. Describe motor operating mechanisms and their hazards 8. Metal Clad Switchgear. 5% a. Describe metal clad switchgear breaker installations. b. Describe characteristics of switch gear breakers 9. Fuses. 10% a. Describe fuses and their applications. b. Describe fuse co-ordination. c. Describe fuse selection. d. Describe short circuits and their calculations 10. Disconnects. 7% a. Describe different kinds of disconnects Centre-break Horizontal and vertical Propeller Single-break Tandemed Vacrupters b. Describe various means of disconnect operation Manual Motorized Insulated switch stick c. Describe various applications, functions including sizing for voltage and ampacity of disconnects 11. Bus-Work. 8% a. Describe the varieties and prescribed applications of buswork Aluminum/Copper Pipe Aluminum/Copper Bar Aluminum/Copper Stranded b. Describe electrical clearances Phase-to-phase Phase-to-ground Indoor/Outdoor Voltage values c. Describe insulators, bushings (including wall bushings) bus supports, and clamps. d. Describe buswork ratings and ampacities. e. Describe requirements for terminating into disconnects, pot-heads, metalclads. f. Describe requirements for insulating buswork to achieve a specified voltage insulating level. g. Describe chemical and metallurgical considerations associated with making electrical connections. (e.g., Copper to aluminum connection) 11 Rev. September 2008

13 Unit: C6 AC Machines Level: Three Duration: 30 hours Theory: Practical: 30 hours 0 hours Overview: This unit of instruction is designed to provide the Electrician apprentice with knowledge and understanding of Industrial AC Motors and generators. Percent of Objectives and Content: Unit Mark (%) 1. Describe three phase motors. a. Squirrel cage induction motors b. Wound rotor induction motors c. Three phase synchronous motors Basic construction Terminal markings Reversing Applications 2. Describe operating characteristics of three phase motors. a. Speed control b. Speed regulation 3. Describe single phase ac motors. a. Split phase induction motors b. Alternating current series motors c. Shaded pole motors Basic construction Terminal markings Reversing Applications 4. Describe alternating current generators. a. Types and construction details b. Operating characteristics and losses c. Paralleling requirements *** 12 Rev. September 2008

14 Unit: C7 Preventive Maintenance Level: Three Duration: 15 hours Theory: Practical: 13 hours 2 hours Overview: This unit of instruction is designed to provide the Electrician apprentice with knowledge and understanding of preventive and predictive maintenance procedures. Percent of Objectives and Content: Unit Mark (%) 1. Discuss the effects of temperature, moisture and contamination on insulating materials. 14.5% 2. Describe the proper testing procedures for making a megohmmeter test. 14.5% a. Lockout / tag out procedures b. Equipment grounding c. Maximum test voltages d. Meter lead connections 3. Discuss methods of trending the condition of insulating materials using a megohmmeter. a. Sixty second test b. Step voltage test c. Dielectric absorption test d. Polarization Indexing e. Temperature correction 4. Describe the minimum resistance IEEE standard for electrical systems and apparatus a. Low voltage wiring systems b. Motors and generators c. Transformers 14.5% 14.5% 5. Describe methods of testing and cleaning insulating liquids. 14.5% 6. Discuss the hazards associated with high potential testing methods. 14.5% 7. Perform insulation tests on electrical systems and apparatus. 13% *** 13 Rev. September 2008