Motor anti condensation heaters and bearing temperature measurement

[Lc85]

Our client says that they do not wish anticondensation heaters fastened to the windings they wish for the heat to be transferred to the windings by convection from heaters mounted on the motor frame. I have never seen this before is this standard for some parts of the globe?

Also they wish the bearing motor temp to be measured by type E thermocouples which again seems strange as usually PT100's are used.

The motors are 3ph 400v,50Hz,7.5Kw and 400V,50Hz,110kW .

Thanks

 

[waross]

That is the way my generators were protected. Some had strip heaters bolted to the motor skin, some had flexible pad heaters lying inside the bottom of the generators. The stator and the rotor need heat. Convection works well.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[squeeky]

Never seen them attached to to windings. Always on the lower section of the internal of the stator.

 

[jraef]

Or band heaters wrapped around the frame.

If they don't like the entire concept, you can also consider internal motor winding heaters, which energize one set of windings with controlled low voltage DC on one winding that uses the winding itself as the heater. They are much more effective because the heat distribution is even throughout the frame plus it uses the existing motor leads, so there is no need to run a separate circuit and transformer.

Allen Bradley Bulletin 1410 or Motortronics MWH Series are two I know of. Also, several Soft Starters and most VFDs can do this as well. If you already have a VFD running this motor, it's worth looking into.

"Will work for (the memory of) salami"

 

[petronila]

Hello Lc85,

Space heater are calculated, depending on the motor enclosure size,please take a look of the attached file. Could help for NEMA motors.

Regards

Carlos