Glossary · Electrical engineering and control panels
Protection (electrical)
Also known as: Electrical protection, Circuit protection
German: Schutz
In electrical engineering, protection is the set of measures and devices that detect abnormal conditions such as overcurrent, short circuit, earth fault or overvoltage and disconnect or limit them, to protect people against electric shock and equipment and cables against damage and fire.
- Control panels
In one sentence
Electrical protection detects overcurrent, short circuit, earth faults or overvoltage and disconnects or limits them to protect people and equipment.
Example
The motor branch combines short-circuit protection by a circuit breaker, overload protection by a thermal relay and fault protection by automatic disconnection.
How it applies
- Engineering: Protection concepts cover overcurrent protection of cables and devices, protection against electric shock (basic protection and fault protection), overvoltage protection and, where required, residual current devices. IEC 60204-1 and the IEC 60364 series specify requirements.
- Commissioning: Verification includes continuity of the protective bonding circuit, insulation resistance and, where relevant, fault loop impedance.
- Documentation: Circuit diagrams show protective devices with ratings. The list's German term "Schütz" was a glitch: "Schütz" is a contactor, "Schutz" means protection. Terminology databases should record both to avoid mistranslation.
Electrical protection vs. protective device (machine safety)
Electrical protection protects against electrical faults. A Protective device in machine safety, such as a light curtain, protects people from mechanical and other machine hazards. Both use the word "protective" but belong to different standards.