Severely Corroded motor frame 1

[edison123]

I have just recd a 3.3 KV, 500 KW tube ventilated, fan cooled, totally enclosed (TEFV) motor for rewind. The motor (driving a cooling tower fan) has severe corrosion on the stator frame on the outside. Corrosion has eaten away top half of the frame to more than 4 mm depth. The terminal box welded to one side of frame has a clear hole right through the top due to corrosion.

Suppose, I cover the top half of stator frame with another 3 mm semi-circular mild steel plate with a clearance of say, two inches, away from the original stator frame, will it affect the cooling of the motor (due to loss of radiation surface and due to the air packet in between the frame and the top cover) ? If so, can anyone suggest alternative method of repairing these corroded areas ?

 

[aolalde]

Edison123.

In my opinion the cooling will suffer minimum change with the proposed jacket.

The cooling of a C.A.C.A motor is made by the interchange of heat trough the ventilated pipes. The internal air circuit gets the heat of the motor elements and transfers it to the pipes surface; the external air circuit goes into the pipes to remove that heat. As far as the internal and external air circuits are not altered, the heat radiated by the frame surface is of minimal proportion.

 

[edison123]

Thx aolalde. Right on the money, as usual.

 

[jbartos]

Suggestion: It is not clear from the original posting, if any cooling piping is corroded. A reconstruction of the original frame should not be objectionable.