Electrical Safety Standards and Human Body Protection

IP68 Protection Standards

The IP68 rating certifies protection against solid objects and liquids.

Electrical Safety and Human Physiology

1. What motivates the passage of electric current through the human body? All listed factors are correct.
2. Are all effects caused by electric current reversible? Yes, all effects are reversible.
3. What causes electrical burns? Burns can be caused by radiant heat, splashes of molten metal, or direct electrical fire sources.
4. What barrier protects us from thermal burns? The skin.
5. What determines the severity of burns? Severity depends on the depth of the action on the affected skin surface.
6. How are burns classified? Burns are classified into first, second, and third degrees.
7. What are the temperature thresholds for skin damage? Damage can occur at temperatures above 45°C and below -44°C.
8. What specifies maximum permissible temperatures for electrical parts? The standard UNE 20-460-4-42.
9. What factors influence the severity of electric current effects?
   • Intensity
   • Frequency
   • Contact duration
   • Current path through the body
   • Mental state
   • Physiological state
10. What current level causes a loss of balance on a ladder or scaffolding? 15 mA.
11. What is the maximum current a person can withstand while holding an electrode? 10 mA.
12. What measures ensure installation safety? Measures include inherent installation design and the use of personal protective equipment (PPE).
13. What is direct contact? Physical contact between a person and an element that is normally under tension.
14. What is indirect contact? Contact with a metal part that is not normally energized but has become live due to an insulation defect.
15. How is protection against direct and indirect contact achieved? It is based on the use of a very low safety voltage, which must not exceed 24V.
16. What are the correct methods for protection against direct contact?
    • Insulation of active parts to prevent accidental contact.
    • Use of barriers to prevent contact by people or animals.
    • Interposition of obstacles to prevent physical approach.
    • Protection by distance (placing out of reach).
    • Complementary protection using residual current devices (RCDs).