Depends on where you are storing it, but in general for a large motor the answer is yes. You want to keep the motor internals dry, and if there is any humidity in the air it is best to put the heaters on.

Thanks guru.may i know what are the things to be considered while hook up the heaters?

Motor heaters are recommended to be hooked up for motors in storage, whenever the storage are is subject to swings in temperature, especially in high humidity enviornments.

As an alternative, motors can be meggared just before they are put into use (6 hours) and if they meggar low, putting a dc welding machine on two phases will circulate current through the motor and dry it out ....This may take four to six hours....

Tom

Also, it is a good idea to actually install a circulation pump in line with your cooling system. It is a common practice for thos who live in cold regions to install a system to circulate heated fluids to keep the engine complete and equal in the heat.

And it you should start this engine at least once per month and allow it to run for no less then 30 minutes min. This will help keep the bearings from becoming pitted and will lubricate the interanls on a regular bassis. I helps to mostly keep the rings from becoming dry and sticking to the cylinder walls. Thus, it prevents gaulling of the walls. 8-)

Maximo

I believe that since this is the electrical engineering forum, he is asking about an electric motor, not an engine.

I think he was referring to an ELECTRIC motor, not an engine...