Protection against direct contact
From Electrical Installation Guide
Two complementary measures are commonly used as protection against the dangers of direct contact:
- The physical prevention of contact with live parts by barriers, insulation, inaccessibility, etc.
- Additional protection in the event that a direct contact occurs, despite or due to failure of the above measures. This protection is based on residual-current operating device with a high sensitivity (IΔn ≤ 30 mA) and a low operating time. These devices are highly effective in the majority of case of direct contact.