NEN 3140 VP — Competent Person

A Competent Person (VP) is an individual authorized to carry out electrical work under the responsibility of the person in charge. NEN 3140 mandates VP certification for anyone who regularly works on electrical installations.

The exam

• 60 questions in 45 minutes
• Pass rate: 70%
• Multiple choice (4 options)
• Retake possible

Topics

1. Legal obligations (Arbowet, NEN 3140)
2. Risk assessment of electrical work
3. Voltage, current, resistance — basic concepts
4. Connection systems (TN, TT, IT)
5. Protective measures (RCD, circuit breakers)
6. PPE (personal protective equipment)
7. Working on live voltage vs. working on dead voltage
8. Inspection and testing

Exam Tips

• Read every question twice — there is often a double negative.
• Master the time-current curve for circuit breakers and RCDs.
• Remember the 5 golden rules for working at zero voltage:
  1. Isolate
  2. Protect against re-energization
  3. Verify zero voltage
  4. Earth and short-circuit
  5. Shield adjacent parts

Common pitfalls

• Confusion between RCD types AC vs A vs B vs F.
• Incorrect estimation of touch voltage (50 V AC / 120 V DC).
• Forgetting to test the RCD before and after work.