September 11, 2012

Motor Space Heaters / Anti-Condensation Heaters


The space heaters or anti-condensation heaters which are commonly used to prevent condensation in motor applications are basically resistant wire heating devices. They are used to maintain internal air temperature above the dew point and keep the motor winding hot. In this way, water accumulation caused by moisture condensation inside the motor is prevented and avoid the ice formation in the motor while motor is not running.
The water condensation on winding occurs only when the electric motor is turned off and enclosure temperature drops rapidly to below the dew point or suddenly motor is turned on in damp or wet condition, this results in winding failure. Use of space heater / anti-condensation tool at the design stage can save the expense of costly rewinds and down time which is more precious.
The space heater / anti-condensation tool shall not be energized when the motor is in running condition.
The motor space heaters are usually used for big motors and decided based on the ambient condition of the motor. Space heaters are recommended for installation in damp locations and should be activated when the motor is de-energized.
Space heater capacity is selected, depending on the size of the enclosure, to maintain the temperature within the motor approximately 5 degree to 10 degree above the ambient temperature.
Usually, one or more heaters are installed on each end of the stator winding.
Use of Space Heaters is recommended for:-
1.     Motor operating in high and very high humidity condition
2.     Electric motors in tropical environment
3.     Well Pumps.
4.     Shipboard and marine equipment
5.     Costal area motors