How Long Does It Take to Prepare for CompEx?
How long it takes to prepare for CompEx depends on your existing knowledge, experience in hazardous areas, and how thoroughly you want to prepare. This guide gives realistic timeframes and advice on how to use your preparation time effectively.
Starting From Scratch — No Hazardous Area Background
If you have no prior knowledge of hazardous area electrical work, IEC 60079 standards, or Ex equipment, expect to need 4–8 weeks of consistent preparation for Ex01/Ex03. This includes:
- Understanding zone classification, gas groups, and EPL
- Learning each protection type — Ex d, Ex e, Ex i, Ex p, Ex t
- Understanding the IEC 60079-1 volume rule for cable glands
- Learning deficiency classification (Category X, A, B, C)
- Understanding the inspection grade system (Visual, Close, Detailed)
- Practising equipment selection and inspection decisions
Some Hazardous Area Experience
If you work in or around hazardous areas and have encountered Ex equipment but haven't formally studied IEC 60079, expect 2–4 weeks of focused preparation. Much of the practical knowledge is already in place — the preparation fills in the formal IEC 60079 framework.
Experienced Hazardous Area Electrician
Experienced practitioners who work daily with Ex equipment often underestimate the written assessment. Even with 10+ years of hands-on experience, the formal classification and standards knowledge tested in the written assessment can catch people out — particularly deficiency classification and the specific IEC 60079 clauses behind each rule. Plan for 1–2 weeks of focused revision.
How you use preparation time matters more than how much time you spend. EX Academy's approach — decision-based practice through inspection simulations and equipment selection scenarios — builds the applied reasoning the assessment tests. Reading notes is useful background; making the decisions repeatedly is what prepares you for both the written and practical assessment.
Recommended Preparation Structure
A structured approach for Ex03/Ex04 preparation (most candidates' primary focus):
- Week 1 — Zone classification, gas groups, temperature classes, EPL. Read the knowledge base articles and work through the gas group and zone tools.
- Week 2 — Protection types (Ex d, Ex e, Ex i). Focus on IEC 60079-1 flamepath rules and IEC 60079-7 terminal requirements.
- Week 3 — IEC 60079-17 inspection grades and deficiency classification. Work through Inspection Simulations 01–08 on EX Academy.
- Week 4 — Consolidation: module questions, remaining simulations, weak area review. Full-length mock exam.
For Ex01/Ex02
Equipment selection practice is the priority — work through all 15 selection scenarios on EX Academy. Scenario 01–03 cover the most frequently examined scenarios; Scenarios 03 and 05 (IIC and polyester bodies) are the most challenging.
Interactive inspection simulations, equipment selection decisions, and 1,185+ practice questions referenced to IEC 60079. Try free — no card required.
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