Most 2391-52 candidates are working full time. Revision happens in evenings and on weekends, and the difference between passing and resitting is usually not how many hours went in — it is whether those hours went into the right things.
Understand what you are being examined on
The 2391-52 is sat in two parts: an open book paper and a closed book paper. They test genuinely different skills, and revising for them the same way is the most common wasted effort.
Open book asks whether you can find and apply a regulation, table or appendix under time pressure. You have BS 7671 in front of you. Knowing that Table 41.3 exists is not the skill — being able to open the book at Table 41.3 in fifteen seconds is.
Closed book asks what you carry in your head. Classification codes, test sequences, the values you are expected to know without looking them up.
If you spend your closed-book revision reading, and your open-book revision memorising, you have them exactly backwards.
Let the weighting tell you where to spend time
Our app’s mock exam distributes its 60 questions across the syllabus in the same proportions the real paper uses:
| Syllabus area | Questions in a 60-question mock |
|---|---|
| Initial Verification | 14 |
| Periodic Inspection | 14 |
| Test Procedures | 12 |
| Certification and Reporting | 8 |
| Fault Coding | 6 |
| Safe Isolation and GS38 | 3 |
| Statutory Requirements | 3 |
Two things follow.
Initial verification, periodic inspection and test procedures are 40 of the 60 questions. Two-thirds of the paper. If your revision time is limited, that is where it goes.
Safe isolation and statutory requirements are 6 between them. That does not make them unimportant — safe isolation is the one that keeps you alive — but it does mean you should not spend three weeks on the Electricity at Work Regulations while your test sequence is still shaky.
A four-week structure
Week 1 — the sequence. Learn the dead and live test sequence from Regulation 643.1 until you can write it out cold, in order, with the regulation numbers. Everything else in the qualification hangs off it. Read the test procedures guide and work the free questions until you stop getting the order wrong.
Week 2 — the two inspections. Initial verification and periodic inspection are 28 of the 60 questions and candidates routinely confuse them. Get the distinction firmly in place: one confirms compliance before service, the other assesses condition in service. Then learn what changes as a result — the document, the sampling, the limitations, the assessment.
Week 3 — coding and certification. Fault coding is where the marks are lost, and it is the one area where reading definitions does not work. You have to code observations and check your reasoning. Use the fault coding trainer, then move to certification — the EIC/MEIWC/EICR decision is quick marks once the rule is clear.
Week 4 — mock exams and the gaps. Sit full weighted mocks under time pressure. The score matters less than the pattern: what you keep getting wrong is your revision list for the last week.
Practise open book with the book
This is the advice most candidates skip, and it is the cheapest mark-winner available.
Buy or borrow your own copy of BS 7671 and use it while you practise. Put tabs on the parts you keep returning to — Chapter 41, Table 64, Appendix 4, Appendix 6. Learn where the index actually takes you, and where it does not.
Turning up to an open book exam with a pristine, unfamiliar copy of the regulations is close to sitting it closed book with extra weight to carry.
Drill the closed-book numbers as pairs
The values that come up in closed book questions have a habit of being examined as pairings, not as isolated facts:
- Insulation resistance: which test voltage goes with which minimum resistance
- Disconnection times: which system, which circuit size, which time
- RCD operating times: general type vs S-type
- CAT ratings: which category, which location
Learn them as rows in a table, and the classic trap — pairing the SELV test voltage with the low-voltage minimum — stops working on you.
Our quick reference cards are laid out as those tables for exactly this reason.
Where candidates lose marks
From the areas the question bank covers most heavily, the recurring ones are:
- Test sequence out of order, particularly polarity before insulation resistance
- Marking an EICR unsatisfactory because of C3 observations. Only C1 and C2 do that
- Coding an older installation C2 for its age rather than for a danger
- Confusing EIC and Minor Works — the test is a new circuit or a board replacement, not job size
- Treating BS 7671 as law. It is not; the Electricity at Work Regulations are
- Giving prove–test instead of prove–test–prove
Every one of those is a definite, learnable answer. None of them requires more experience — just knowing which side of the line the answer sits on.
Use the free material first
Everything you need to start is free and needs no sign-up: seven study guides, practice questions in every area, four calculators, quick reference cards and the fault coding trainer.
When you want the full question bank and weighted mock exams under real time pressure, the app has them.
