CompEx Practical Assessment — What to Expect on the Day
The CompEx practical assessment is a demonstration of hands-on competency assessed by an accredited CompEx assessor. Unlike the written assessment (which tests knowledge), the practical tests your ability to apply that knowledge to real Ex equipment in a realistic work scenario. Many candidates find the practical more challenging than the written — not because the tasks are difficult, but because the decisions must be made calmly and methodically under observation.
What the Practical Assessment Involves
For Ex03/Ex04 (Inspection Units)
You will be required to carry out a structured inspection of Ex equipment — typically one or more pieces of equipment representing the types covered by the unit. You will need to:
- Carry out a visual inspection and identify visible deficiencies
- Carry out a close inspection — opening the equipment, checking gland engagement, terminal condition, flamepath
- Classify each deficiency found using the Category X/A/B/C system
- Correctly document your findings
- Demonstrate correct reassembly — all bolts returned, correctly tightened
For Ex01/Ex02 (Installation Units)
You will be required to install and connect Ex equipment to a given specification. This includes:
- Selecting and fitting the correct cable gland(s) for the entry type
- Achieving minimum 5 full thread turns on Ex d entries
- Fitting correct accessories (IP washers, banjo earth tags as applicable)
- Making correct internal connections
- Correctly sealing any unused entries
- Demonstrating earthing continuity
What the Assessor is Looking For
The assessor observes your process as well as your outcome. They want to see:
- Systematic, methodical approach — not rushed or random
- Correct identification of deficiencies — including those that are easy to miss
- Correct classification of every deficiency found
- Safe working — correct use of isolation and permit to work procedures
- Correct reassembly — particularly all bolts returned and adequately tightened
The most common causes of failure in the CompEx practical assessment are: (1) Missing a Category X deficiency — particularly missing bolts or open cable entries. (2) Incorrect deficiency classification — calling Category X as Category A. (3) Incorrect reassembly — not returning all bolts. (4) Not checking gland thread engagement. (5) Rushing — missing items through going too fast rather than following a systematic checklist approach.
How EX Academy Prepares You for the Practical
EX Academy's 15 inspection simulations present each scenario as a structured work order — the same format you will face in the practical assessment. By working through multiple scenarios under simulated conditions, the systematic approach becomes habitual. When you face the real assessment, the process feels familiar rather than stressful.
Interactive inspection simulations, equipment selection decisions, and 1,185+ practice questions referenced to IEC 60079. Try free — no card required.
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