Brushless DC Permanent Magnet Motor

Three-phase low-speed induction motors of the series PMH are intended for direct drives of axial-flow fans for cooling towers without gears, for the environment with the ambient temperature up to + 40 °C (PMT up to +60°C). Due to a direct low speed the noise and vibration levels are reduced, life of the parts of the set is longer, the assembly costs are reduced and the requirements for maintenance are lower in comparison with a highspeed motor with a gearbox. Removal of a gearbox with oil filling is also beneficial for environment protection. The motors are designed for a possibility of the speed-changing ratio 1 : 2, enabling thus a more economical adjustment of the cooling power of a tower in different climatic conditions. They may be also delivered as singlespeed ones (without the designation D). The PMH motors are made for humid environment corresponding to the conditions of cooling towers - relative humidity up to 100 %, temperature of moist air being delivered (forming at the same time a cooling agent removing heat losses from the motor surface) up to + 40 °C (PMT up to +60°C)