ELM 2010 - Commercial Wiring I

• Define the basic units for electrical voltage, current, resistance, energy, and power.
• Calculate electrical power.
• Discuss the characteristics of series, parallel, and complex circuits.
• Calculate voltage, current, and resistance in series, parallel, and complex circuits.
• Describe and compare alternating current and direct current.
• Explain the functions of basic components of an alternator.
• Explain the effects of inductance and capacitance in ac circuits.
• Calculate power factor and impedance in ac circuits.
• Describe single-phase and three-phase electrical systems.
• Recognize wye and delta configurations.
• Distinguish between nominal voltage and rated voltage.

Safety

• Cite examples of hazardous situations.
• Identify hazards associated with electrical work.
• Explain basic safety rules.
• Describe safety equipment and protective clothing.
• Follow basic procedures designed to aid an injured worker.

Tools

• Recognize the basic construction tools used by electricians.
• Identify the tools used specifically for electrical installation.
• List basic safety rules for using tools.
• Identify various types of bending tools and pulling equipment.
• Explain the functions of various electrical testing devices.

Electrical Prints, Specifications, and Codes

• Describe several types of electrical drawings.
• Identify common electrical symbols.
• Explain the purpose of specifications.
• Explain the importance of building codes.
• Define the purpose, intent, arrangement, and key terminology of the National Electrical Code.
• Name various agencies that set standards concerning electrical practices and procedures.
• Identify various lab facilities that perform rigorous testing on electrical devices, equipment, and associated components for safety and performance certification.

Wiring Methods

• List the wiring methods available for commercial installation and the rules regarding each method of wiring.
• Size wireways to satisfy Code requirements.
• Identify fittings, connectors, supports, and other integral hardware unique to a particular wiring method.
• Select the correct wiring method based on Code requirements.
• Calculate wireway size.

Conductors

• Recall the Code rules regarding conductors for general wiring.
• Identify the different functions of conductors in an electrical system.
• List the factors that affect the conductor ampacity rating.
• Explain the cause of voltage drop and compute the voltage drop of a conductor.
• Select different types of conductors.
• Size conductors based on circuit load using the Code.
• Use the Code to adjust conductor ampacity based on ambient temperature and the number of conductors.
• Designate conduit sizes based on permissible percentage fill of conduit.

Boxes and Conduit Bodies

• Identify different types of boxes.
• Select boxes for various applications.
• Explain how boxes are grounded.
• Mount and support boxes in accordance with the Code.
• Identify various types of conduit bodies.
• Perform box fill calculations using the Code.
• Compute box sizes for straight and angular pulls.

Overcurrent Protection

• Identify the types, ratings, and characteristics of electrical protective devices.
• Recognize overloads and short circuits.
• List types of fuses.
• Compare fuses and circuit breakers.

Service and Distribution

• Describe the two basic types of service.
• Explain service terminology.
• Find service drop clearance in the Code.
• Compare the arrangement and construction of service drops and service laterals.
• Identify the required working clearances at the service equipment.
• Explain the various supply voltages available in the United States and their common applications.

Transformers

• Define the purpose and uses of transformers.
• Identify the basic components and construction of a transformer.
• Explain how a transformer works.
• List the types of transformers.
• Size overcurrent protective devices for transformer primaries and secondaries.
• Perform transformer calculations and solve practical transformer problems.

Grounding

• State important grounding concepts.
• Explain the difference between system grounding and equipment grounding.
• Compare the characteristics of grounded and ungrounded systems.
• List the primary reasons for grounding equipment.
• Select the appropriate size system and equipment grounding conductors using the Code.
• Identify the requirements for a service grounding system.
• Explain the purpose, operation, and installation of ground-fault circuit-interrupters.
• Describe various grounding electrode systems and their Code requirements.

Branch Circuits and Feeders

• Identify the feeder and branch circuit portions of a distribution system.
• Describe the various types of branch circuits.
• Define the functions of a feeder and the functions of branch-circuit conductors.
• Calculate lighting and receptacle loads using Code requirements.
• Size branch circuits in accordance with the Code.
• Determine branch circuit overcurrent protection required by the Code.

Motors

• Explain the basic components of motors.
• List various classes of motors.
• Calculate motor starting currents.
• Use the Code to design motor branch circuits, including overcurrent protection.

Motor Controls

• Describe manual and magnetic starters.
• List Code requirements for motor controls and motor control circuits.
• Determine the proper overcurrent protection and conductor sizes for a control circuit.
• Identify several types of pilot devices.
• Read control circuit diagrams.
• Reverse motor direction by switching connections.
• Describe basic motor control center setup.

Emergency Power

• Identify equipment to be supplied by emergency power and standby power.
• Explain the operation of an automatic transfer switch.
• Describe various sources of emergency power.
• Compare optional standby systems to legally required standby systems.

Hazardous Locations

• Distinguish between various classes of hazardous areas.
• Summarize ignition and combustion principles.
• Cite criteria defining hazardous areas.
• Identify hazardous areas based on Code specifications found in Article 500.

Pools and Fountains

• Cite the requirements for receptacles and luminaire placement around pools.
• Describe various types of underwater luminaire.
• Identify limitations and clearances for conductors passing over pools.
• List the Code rules for bonding and grounding equipment near a pool.
• Identify the Code requirements for spa and hot tub installation.

Maintenance and Troubleshooting

• Care for testing equipment.
• Troubleshoot a power circuit, power supply, control circuit, and control transformer.
• Identify major causes of motor breakdown.
• Explain the importance of preventive maintenance.
• Perform several troubleshooting tests.