NEN 1010 §525 (Annex B)
Voltage drop
Spanningsval
Also known as: voltage-drop, spanningsdaling, udrop, udaling, undervoltage, onder-spanning, onderspanning, low-voltage-fault, spanningsval-525, bijlage-h, 4-procent, voltage-drop-limit, cable-voltage-drop, eindgroep-spanningsval, spanningsverlies-meten, voltage-drop-meting, delta-u-belasting, u-begin-u-einde
Voltage drop: decrease in phase voltage between main distribution point and furthest load point due to conductor impedance. NEN 1010 §525 specifies reference values: 3% for lighting and 5% for other end groups, measured against 230 V. For longer cables or heavy loads, conductor cross-section must be increased.
Practical example
Voltage drop: A 16 A radial circuit of 30 m in 2.5 mm² Cu at 230 V fully loaded gives ≈ 8.6 V drop (3.8%) — just within the standard, but tight at greater lengths.
Common mistake
Voltage drop Common mistake: Selecting only based on Iz and forgetting voltage drop — typical in kitchens, charging points, and outbuildings where the socket is far from the distribution board.
See also
Related terms
In-depth guides
- → §525 §525 — Voltage drop: the 3%/5% limit and when it becomes decisive
- → §443 Surge Protection (SPD)
- → NEN-EN 50160 Voltage unbalance in three-phase networks — NEN-EN 50160
- → §414 SELV, PELV & FELV — the extra-low-voltage measure
- → §715 / IEC 60364-7-715 §715 — Extra-low-voltage lighting installations
- → IEC 60364-4-41 Conventional touch voltage limit UL — 50V and 25V
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