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Module Lessons
Electrical Principles & Diagnostics
Ohm's Law & Electrical Power
Protection Against Electric Shock
Electrical Statutory Regulations
BS 7671 & IET Guidance Documents
Reading Electrical Plans & Diagrams
Consumer Units & Protective Devices
Lighting & Power Circuits
Earthing, Bonding & ADS
Electrical Accessories
Current-Using Equipment & Specialist Controls
Effects of Electric Shock on the Body
Tool & Equipment Safety Classes
The Safe Isolation Procedure, Step-by-Step
Hand Tools for Electrical Work
Cable Types
BS 7671 Termination Requirements (Section 526)
Terminal & Connection Types
Cable Glands & Enclosure Entry
Terminating Flexes & Single-Core Cables
Terminating Flat Profile (Twin & Earth) Cable
Installing Main Protective Bonding
Fitting & Labelling BS 951 Bonding Clamps
Electrical Test Instruments
Central Heating Control Sequence of Operation
Diagnosing Boiler Thermostats & Fans
Diagnosing Air Pressure Switches
Diagnosing PCBs & Ignition Components
Diagnosing Thermocouples & Thermistors
Alternative & Emerging Heat Sources
Testing Immersion Heaters
Isolating & Correcting Appliance Faults
Lesson Overview
Safe electrical diagnosis requires purpose-built, calibrated test instruments that comply with UK safety standards. This guide covers the essential instruments, HSE Guidance Note GS38 requirements, and their correct workshop and site applications.
Learning Objectives
Identify approved electrical test equipment and their dedicated diagnostic functions.
Apply HSE Guidance Note GS38 design standards for leads, probes, and instruments.
Differentiate between safe non-invasive current testing and hazardous live series measurements.
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