Class 2 Electrician:Theory Zimbabwe

Trade Test Class 2 Electrical

• A Class 2 electrician works under a Class 1 electrician's supervision.
• Class 2 scope of work is more limited than that of Class 1 electricians.
• Essential knowledge includes electrical theory, regulations, and safety.
• Wiring, installations, and fault finding require practical skills.
• Electrical drawings and diagrams must be understood.

Regulations and Standards

• Compliance with local and national electrical codes is a must.
• The National Electrical Code (NEC) is used in the United States.
• Wiring methods, overcurrent protection, and grounding are regulated.
• Compliance with safety standards prevents electrical hazards.

Electrical Theory

• Voltage, current, resistance, and power are fundamental concepts (V=IR, P=VI).
• It is necessary to understand AC and DC circuits.
• Series, parallel, and series-parallel circuits should be known.
• Calculating voltage drops, current flow, and power dissipation is essential.
• You should understand resistors, capacitors, inductors, transformers, and diodes.

Wiring Methods

• Selection and installation of cables and conductors must be done correctly
• Conduit, cable tray, and direct burial are examples of wiring methods.
• Correct termination and connection techniques ensure safety and reliability.
• Cable sizing and derating factors must be understood.

Electrical Installations

• Lighting fixtures, receptacles, and switches should be installed.
• Electrical panels and distribution boards should be wired.
• Motors, transformers, and equipment should be installed.
• Electrical systems must be grounded and bonded for safety.
• Wiring techniques must be correct for different equipment and applications.

Electrical Drawings and Diagrams

• Electrical drawings like single-line, wiring, and schematic diagrams should be read.
• Electrical symbols and notations should be understood.
• Drawings are used to locate components and circuits.
• Electrical systems should be installed and troubleshooted using drawings.

Testing and Measurement

• Multimeters are used to measure voltage, current, and resistance.
• Cables and equipment are tested for insulation breakdown.
• Circuit and connection integrity is verified.
• Grounding of electrical systems is tested.
• Specialized equipment is used for motor or power quality analysis.

Fault Finding and Troubleshooting

• Electrical faults are diagnosed using systematic methods.
• Common issues include short circuits, open circuits, and ground faults.
• Testing equipment locates faults in circuits and equipment.
• Faulty components and wiring are repaired or replaced.
• Electrical hazards are avoided by following safety procedures.

Safety Practices

• De-energize when working on circuits.
• Use PPE such as gloves, safety glasses, and insulated tools.
• Lockout/tagout prevents accidental energization.
• Be aware of arc flash and electrocution risks.
• Follow safe work practices near live equipment.
• Know first aid for electrical shock.

Motors and Control Circuits

• AC and DC motors' operational principles should be understood.
• Motor starters, contactors, and overload relays must be known.
• Motor control circuits should be wired and troubleshooted.
• Motor protection methods must be known.
• Variable frequency drives (VFDs) and their uses should be understood.

Transformers

• Transformer principles of operation must be understood.
• Types of transformers should be identified such as step-up, step-down, and isolation
• Transformers are connected in single-phase and three-phase.
• Transformer testing and maintenance is performed.

Protection Devices

• Circuit breakers, fuses, and GFCIs should be understood.
• Protection devices should be selected for circuits and equipment.
• Protection devices should be tested to ensure operation.

Lighting Systems

• Lighting fixtures, including incandescent, fluorescent, and LED should be installed and maintained.
• Lighting control systems like dimmers and occupancy sensors should be understood.
• Lighting levels should be calculated and appropriate lighting selected.

Communication and Interpersonal Skills

• Communication must be effective with supervisors, coworkers, and clients.
• Instructions should be followed and you should work as part of a team
• Conduct must be professional and ethical.

Specific Tasks

• Cables should be installed and terminated in electrical panels.
• Lighting fixtures and receptacles should be installed.
• Equipment should be wired and connected.
• Electrical faults should be troubleshooted.
• Preventive maintenance should be performed on systems.
• Safety procedures must be followed.

Tools and Equipment

• Hand tools such as pliers, screwdrivers, wire strippers, and crimpers should be known.
• Power tools such as drills, saws, and conduit benders should be used.
• Testing equipment such as multimeters, insulation testers, and ground resistance testers should be operated.

Knowledge of Materials

• Types of wires, cables, and conduits should be identified
• Properties and applications of electrical materials must be understood.
• Appropriate materials should be selected for installations.

Codes and Standards Updates

• Codes and standards revisions should be followed
• How code changes affect work practices should be understood.

Emergency Procedures

• Emergency procedures should be known for electrical accidents or fires.
• First aid techniques should be known for shock victims.
• Systems should be shut down in emergencies.

Renewable Energy

• Renewable energy systems like solar PV and wind should be understood.
• Solar panels and wind turbines should be installed and maintained (basic).
• Renewable energy systems should be connected to the grid (basic).

Automation and Control Systems

• Automation and control systems should be understood in buildings.
• Programmable logic controllers (PLCs), sensors, and actuators should be known (basic).
• Control circuits should be wired and troubleshooted.

Class 2 Electrician Scope

• Class 2 license limitations should be understood, especially supervision.
• Tasks needing Class 1 electrician supervision should be known
• When work exceeds the license scope must be recognized.

Covers the scope, regulations, and theory for Class 2 electricians. It emphasizes compliance with electrical codes, safety standards, and understanding fundamental concepts like voltage, current, resistance, and power. Practical skills and knowledge of electrical drawings are crucial.