Let me know why we found moisture usually inside the Motor body when dismental for maintenance even specification is EEx de II C T4, IP 55.

perhaps you would be so kind as to share a bit more information with us.

Like, the environment in which the motor is installed ..... i.e., indoor? outdoor?
( I would guess mtr. is outdoors or in an un-heated building or room) ...


Ambient temperature range to which the motor is subjected ?


How many hours a day does the motor operate ?

How many days a week is the motor operated ?

Is the motor un-powered and un-heated over the weekend ?


Condensation is virtually impossible to keep out of a motor, regardless of construction; especially when it is subjected to wide temperature extremes or is left in an unheated environment for extended periods of time. Typically occurs when the ambient temperature falls below the dewpoint.


Suggestion: Have thermostatically controlled space heater installed in motor. Circuit should be designed so that space heater is energized when motor is not powered.

This will prevent condensation from occurring inside the motor.

Dear sethar,

IP55 means that the motor is protected v/s rain, not v/s moisture.

All EEx de motors must have an internal small air duct (lamination) for exaust gases in case of an internal explosion.
Please check also if there is the right quantity of grease near bearing, to improve moisture resistance.

In some application it is accepted a continuour heating during stand-by using the same motor windings, feeded at very low voltage.

Regards
Mario