EN 50365 sets the requirements for an electrically insulating helmet for work on or near low-voltage installations. The helmet is tested at 10 kV a.c. and its leakage current is tightly limited.
How this differs from the 440 V marking in EN 397
The optional 440 V a.c. marking in EN 397 means protection against accidental, momentary contact — it is not intended for deliberate work on a live installation. EN 50365 is: it treats the helmet as an item of insulating equipment and tests it accordingly.
- The helmet is marked with the double-triangle symbol (class 0).
- The helmet must also conform to EN 397 or EN 12492 for mechanical protection.
- Metal parts, ventilation holes and conductive accessories are not permitted.