Corrections
Errors we found and fixed are listed here. Spotted something wrong? Report it via the link at the bottom of any guide.
2026-10-03
Guides: current-time curve (IEC 60479-1), arc flash, theory practice questions, overvoltage categories, exceptions §433.3/§434.3
Physiological thresholds aligned: perception about 0.5 mA, let-go about 10 mA, ventricular fibrillation from about 40 mA for exposure of seconds (curve c1). Some pages previously said 0.25–1 mA, 5 mA and 50 mA, and "atrial fibrillation"; the statement that 30 mA is "well below the let-go threshold" was also wrong (30 mA is above it). Added: impulse withstand voltages per overvoltage category (230/400 V: 1.5/2.5/4/6 kV) and the remaining exceptions of §433.3.1.
2026-10-03
Guides: MCCB vs. MCB, §433, fire extinguishers, sauna (§703), §524, distribution-board diagram, first aid
MCCB: the conventional tripping current is 1.30 × In (IEC 60947-2), not 1.45 × In as for an MCB (IEC 60898-1); the sentence saying IEC 60898-1 "does not apply" for ordinary persons was replaced by the actual difference in user group and current range. EN 3-11 only covers small Li-ion batteries (up to about 600 Wh). Sauna: zone 3 requires equipment rated for at least 125°C. Distribution-board diagram: assumed reasons are now marked as such. A table number and a Red Cross attribution were removed because we could not verify them.
2026-10-02
Practice question on the BA4/BA5 classification (practical bank)
The labels were swapped: BA5 = skilled (VP), BA4 = instructed (VOP). The question now refers to the VP/VOP roles of NEN 3140 / NEN-EN 50110-1; the BA classes come from IEC 60364-5-51 (NEN 1010 §512). The glossary entry was updated.
2026-10-02
Guide: measuring protective conductor continuity
Fully rewritten using Dutch terminology (instrument ≥ 200 mA per NEN-EN-IEC 61557-4, direct and loop method, zeroing). The British term "R1+R2" was replaced throughout the guides.
2026-10-02
Guides and questions that cite the Bouwbesluit
The Bouwbesluit 2012 was replaced by the Besluit bouwwerken leefomgeving (Bbl) on 1 January 2024. References were updated and an unverifiable article number was removed.
2026-10-02
Test results and certificate page
Made clearer that a result is a practice result, not an NEN 3140 certificate; a VP/VOP/LP designation only follows from a written designation by the employer.
2026-10-02
Ukrainian translations (12 guides and the glossary)
Russian terms (УЗО, утечки) replaced with the Ukrainian ones (ПЗВ, витоку).
2026-10-03
Measuring-instrument CAT; EV charging (§722); arc flash and PPE
Meter cupboard/main fuse is CAT IV (not CAT III); wallbox DC detection now cites only IEC 62955; NFPA 70E thresholds are marked as a US orientation (Europe: IEC 61482-1-1/-1-2) and the ≤ 40 cal/cm² row was added; the 40-question guide was renamed to practice questions (not official exam questions).