Operating temperature maintaining for electric motor drive of e.g. fire protection curtain, in building, involves subjecting part of motor coils of electric motor with filament current, and heating motor coils using thermocouple

摘要

The method involves subjecting a part of motor coils of an electric motor with filament current. Movable closure devices are locked in position by a brake during current supply to the parts of the motor coils. The motor coils are heated by a thermocouple depending on an ambient temperature in a controlled manner for a specific period that constitutes a fraction of a cycle time that is permitted by an electronic load relay, where the motor coils are heated with a pulsed alternating voltage of 230 volts.