motorvédelmi

Motorvédelmi refers to the field and practice of protecting electric motors and motor-driven equipment from damage caused by electrical faults, overloads, and adverse operating conditions. It covers devices, systems, and design practices that detect abnormal conditions and interrupt or regulate motor operation to prevent harm to the motor, the drive system, and personnel.

Common protection functions include overload protection, short-circuit protection, phase loss or imbalance protection, undervoltage or overvoltage protection, and stall or thermal protection. Overload protection monitors motor current or winding temperature to prevent overheating. Short-circuit protection uses fast-acting devices such as fuses or circuit breakers. Phase loss or imbalance protection detects missing or unequal voltages between phases. Undervoltage or overvoltage protection ensures the motor operates within safe electrical limits. Thermal protection often relies on sensors embedded in windings or electronic motor protection relays that monitor temperature and trip when predefined limits are reached. Electronic motor protection relays can combine multiple protections and offer communication with automation systems.

Protection devices include thermal overload relays, motor protection relays, soft starters, and variable frequency drives, which may incorporate built-in protection features. Mechanical and environmental protections, such as proper enclosure IP ratings, guarding, grounding, and fault-current protection, complement electrical protections and help ensure safe operation.

Applications span industrial automation, pumps, fans, conveyors, compressors, and machine tools. Design considerations include motor rating, duty cycle, ambient temperature, enclosure type, coordination with upstream protection, and integration with control systems. Standards relevant to motor protection cover electrical equipment of machines and electrical installations, with specifics varying by region.