what is the use of space heater in MCC?

Question

Generally it is intalled in electrical panel.

Answer 1

Space heaters and thermostats may be installed in electrical enclosures to prevent condensation.

Answer 2

They are used to warm the ambient of those devices (or panels) especially in humid places where the temperature difference in a day is high enough to make dew to be created. In order to prevent producing water drops in electric contacts (like switches, motor brushes, etc.) it is required either to dehumidify the ambient (using dryers and dew-point adsorbers) or to fix the temperature to a constant. This is what a space heater does.