Answer / ankamsreekar

Electric motors frequently have space heaters (or strip
heaters) installed to prevent moisture condensation in the
motor during times the motor is not running.

Many motor manufacturers use metallic or ceramic cartridge
heaters for this purpose. Because such heaters are small,
they must operate at a high surface watt density and
consequently high temperature.

Answer / ash

When a motor is built as a "totally enclosed" (TE) unit, no free interchange of air can take place between interior and exterior. That's good protection against entry of solid or liquid contaminants.

But no enclosure can be airtight. As the TE motor heats and cools between "on" and "off," or from day to night, outside air will "breathe", in and out, and the water vapor in that air will condense on interior surfaces of winding and bearings. The result will eventually be insulation failure and bearing corrosion.

To prevent that, the motor's interior needs to be kept warm — above the condensation temperature — whenever it's not running. This is particularly true for motors that run only a few hours a day, are seasonally idle, or are installed in unusually damp locations. It's not a function of motor size or type. The same conditions exist, and will be equally damaging, whether the motor is 1 horsepower or 1000.

Answer / k.prakashchandra

It is used to warm up inside of panel or motor .In case of
motor,now instead of flat space heater ,current is passed
through winding using a transformer

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