METHOD FOR PROTECTING ELECTRIC MOTOR WINDINGS AGAINST MOISTURE CONDENSATION Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: during maintenance intervals, upon disconnection of motor from supply mains, ambient temperature and relative humidity are measured together with winding temperature and difference between the latter and ambient. Specified winding temperature rise desired to prevent moisture condensation in windings is determined depending on ambient temperature and relative humidity. As motor cools down, values obtained are compared with specified winding temperature rise and as soon as specified temperature rise is attained, motor windings are connected to regulated current source. Current magnitude through windings is adjusted so as to ensure heat release from them in quantity equal to heat released by motor into the atmosphere at specified winding temperature rise. When ambient temperature and relative humidity vary, specified winding temperature rise is changed as well as current passed through windings. EFFECT: improved effectiveness and economic efficiency of motor heating. 2 dwg