Verification is not optional — it is a legal requirement that must be carried out by the authorised company before the installation is energised. Here are the sequence, the measurements and the documentation requirements to DS/HD 60364-6.
Introduction
All new and modified electrical installations must be verified before they are energized. Verification consists of two parts: inspection (without power) and testing (with measurements). The order is not accidental – the inspection must always be carried out first. (Source: DS/HD 60364-6, elsikkerhed.dk/krav-til-verifikation)
A. Inspection — de-energized
Inspection is a visual and mechanical check that verifies the installation has been carried out correctly before power is applied. Control points include:
- 01Protection against electric shock is intact (insulation, enclosure, distances).
- 02Fire protection and cable selection are correct — e.g. halogen-free cables in escape routes.
- 03Conductor cross-section and quality correspond to the dimensioning.
- 04Selection and setting of safety devices (fuses, RCD's) fit the circuit.
- 05Marking and documentation are in place (course diagrams, panel labels).
- 06Grounding and potential equalization system is installed correctly (TN-S, TN-C-S, TT or IT as designed).
B. Testing — With Measurements
Testing is performed with instruments and verifies the electrical properties of the installation. The order is set in the standard:
- 01Continuity in PE conductors and compensation connections.
- 02Insulation resistance: at least 1 MΩ per circuit (verified stricter requirement acc. to DS/HD 60364-6, table 6.1). (Source: elsikkerhed.dk/krav-til-verifikation)
- 03Polarity test — phase and neutral are not reversed.
- 04RCD testing: 0.5× and 5× rated trip current. Example: 30 mA RCD is tested at 15 mA and 150 mA.
- 05Phase sequence (3-phase systems).
- 06Voltage drop measurement under expected load – not just calculated, but measured.
- 07Functional tests of the entire circuit.
Insulation resistance — test voltage and limits
Insulation resistance is measured with an insulation tester (megger) that applies a DC test voltage. Both the test voltage and minimum requirement depend on the circuit's rated voltage (table 6.1 / table 61 in DS/HD 60364-6):
| The circuit's nominal voltage | Test voltage (DC) | Min. insulation resistance |
|---|---|---|
| SELV and PELV | 250 V | 0,5 MΩ |
| Up to and including 500 V (incl. FELV) | 500 V | 1,0 MΩ |
| Over 500 V | 1000 V | 1,0 MΩ |
Measurement is made between the active conductors themselves and between active conductors and earth/PE. Disconnect sensitive electronics and surge protection (SPD), which otherwise can give falsely low results or be damaged by the test voltage. (Source: DS/HD 60364-6, table 6.1 — web-verified.)
Loop impedance and expected fault current
Zs measurement (fault loop impedance) tells whether a fault will trigger protection quickly enough. The instrument temporarily applies a known load and measures the voltage drop. The expected fault current is calculated from Zs:
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