Does a TEFC motor terminal box need to be sealed on the inside.
I think I know, but what does TEFC mean?
totally enclosed fan cool motor
I would think that is a question best answered by the manufacturer of the motor. They would be able to know whether part of a seal is missing.
If you are referring to sealing the area where the motor leads enter the stator housing I would think it is not necessary on a typical TEFC motor, but not all TEFC motors are created the same. The two areas that I have seen where motors are sealed in such fashion are in hazardous locations and submersible pump motors. (potted). May I ask more detail about the installation?
If the motor manufacturer nameplate does not have a Hazardous Location rating, then the motor leads do not have to be sealed. So, the motor has to be used in Non-Hazardous locations only. If the motor does have the UL Hazardous Location nomenclature, then the leads will be factory sealed and is suitable for use in the Hazardous Class/Division that is listed on the nameplate. Field sealing, if it can be done at all, is not acceptable. Here's a photo of a motor with the UL listing on the nameplate for Hazardous Locations.
TEFC only means that the motor is "sealed" from environmental contaminants and is cooled by passing air over the exterior of the motor. The UL label is the determining factor on where the motor can actually be used.
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