Learning outcomes
- Explain the core concepts in plain New Zealand English.
- Recognise the safety, legal and practical implications.
- Apply a structured check before taking action.
Module 3 · Lesson 1
Voltage Current Resistance and Power
Review electrical quantities and calculations used in domestic and commercial installations.
Before you begin
Use current official documents. Confirm the work category, who is authorised, whether certification or inspection is needed, and whether isolation can be safely achieved.
Core lesson
Review electrical quantities and calculations used in domestic and commercial installations.
- Identify the scope. Define the installation, equipment, environment and intended result.
- Check authority. Confirm whether the task is prescribed electrical work and who may legally perform, supervise, certify or inspect it.
- Control risk. Plan isolation, lockout, proving dead, suitable test equipment, PPE and emergency response.
- Apply the relevant rules. Use current legislation, cited standards, manufacturer instructions and network requirements.
- Verify and document. Complete required visual checks, tests, records, certificates, labels and handover information.
Ian's practical tip: Never let familiarity replace verification. Stop when the job, authority, isolation point or test result is uncertain.
Practical activity
Create a one-page worksheet for this topic with five headings: scope, hazards, authorised person, verification and records. Use a real installation only for observation—do not dismantle or energise equipment.