Space heater for Totally Enclosed Fan Cooled(TEFC) Motors?

[CuriousElectron]

Hello All,
Does a TEFC type motor require electric heaters to keep it warm and dry when the motor is idle? Does it depend upon environment and if the area has high humidity. If there is high humidity, then higher chance of condensation?
Thanks for your thoughts.

 

[Gr8blu]

As a general statement, electrical insulation does not like moisture. Specifically, the insulating properties of the material(s) tend to deteriorate when exposed to moisture, since they also tend to absorb moisture.

A machine exposed to the elements (i.e. installed outdoors, for example) or in a moderate- to high-humidity environment can benefit from anticondensation heaters. If the temperature is known to approach the dew point at some time during a 24-hour period, airborne moisture condenses on exposed surfaces and "drips" into some unlikely places - even on TEFC machines.

The trade-off is that most TEFC machines are very limited on space inside the machine enclosure - which makes it hard to fit in a heater and maintain appropriate electrical and mechanical clearances to other parts.

 

[TugboatEng]

In my experience, TEFC motors are not sealed. The ends are not gasketed and there are vent holes at the bottom of the motor.

If you can't install heaters inside, you may be able to apply heating pads to the outside of the motor or use a radiant heat source directed at the motor.