Re-painting enclosures of industrial electric motors

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salahaas

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Good day all, I am looking for any standards or guidelines to follow for re-painting the enclosures (Frames) of industrial electric motors specially operating in corrosive and very hot environment. Regards, Salah
 
Your best bet is to contact the local motor rewinding service. Adding any kind of coating to a motor will negatively effect it's ability to release heat.
 
did the frames have a coating to start with? if not then perhaps those are not the right motors for the application?
heat transfer could (maybe) be an issue if you use the wrong paint, but i suspect not.

perhaps some sort of zinc primer might work, like a zinc chromate spray can, or rustoleum organic zinc primer brush on (400°F/204°C continuous), or rustoleum cold galvanizing spray. but check the application notes for temp range, etc. the zincs are good for corrosion resistance, etc.
 
For the frames coating, yes they are originally coated by their manufacturer. However with time, the coating gets deteriorated and we need to repair this coating defect with reference to standards and guidelines to avoide motors overheating due to improper application of coating in the field.
 
For the frames coating, yes they are originally coated by their manufacturer. However with time, the coating gets deteriorated and we need to repair this coating defect with reference to standards and guidelines to avoide motors overheating due to improper application of coating in the field.

ah, if you need to meet specs then you need to 1) have the specs, and 2) find the right coating. i however do suspect that a coat of zinc chromate spray does not impact heat transfer enough to worry about.

good luck.
 
May be corrosion engineers can help, I heared there are some Nano Thermal Conductive Coatings to prevent overheating of electrical motors and need special contractors to apply it.
 
What is the corrosive agents involved?

Is it compounded by presence of water on any kind of regular basis?
 
Moisture is the most corrosive agent involved, either in the form of rain, condensation, or high relative humidity.
 
That's why corrosion engineers usually specify the proper Thermal Conductive Coatings to prevent overheating at the motors.
 
Unless operating conditions are already pushing the motor to its thermal limit, a coat of paint will not make a noticeable difference in the life of the motor.

Just my opinion....
 
Unless operating conditions are already pushing the motor to its thermal limit, a coat of paint will not make a noticeable difference in the life of the motor.

Just my opinion....

+1. You just described no reasonable application. I know of no engineering plan that would call for an operating condition to be close to any fail or max limit.

If the motor is running near thermal limits of failure then its very likely the wrong item for the task at hand (work + environment).

If a 2-3mil layer of Rustoleum epoxy spray causes the motor to overheat and fail, i'll bet $1mil that the the motor chosen was wrong (for many reasons).

Surely there may be warranty terms to consider. If no warranty exists then just spray the darn thing and be done with it (using correct choice of paint, etc).

There are some ceramic style coatings that will actually become better anti-corrosion as they cure over time from the heat of the object it is applied to, but spray is just easier.

Let us know what you (OP) find and finally do.
 
This table is based on solar radiation absorption factors

White lead paint coating 0.25*
Light cream paint coating 0.35
Aluminum paint coating 0.55
Gray paint coating 0.75
Mat black paint coating 0.97.

*Not available for environmental reasons, for comparison only.
 
This table is based on solar radiation absorption factors

White lead paint coating 0.25*
Light cream paint coating 0.35
Aluminum paint coating 0.55
Gray paint coating 0.75
Mat black paint coating 0.97.

*Not available for environmental reasons, for comparison only.

This is not *directly* related to the matter at hand, which is thermal conduction and emission...the motor itself is generating heat, not necessarily absorbing it from another source, and the concern is that a coating will have some insulating properties. But it is interesting to note the fact that color is one factor here. Light colors absorb heat less efficiently, but also radiate it less. For a heat source where radiation is desirable, black is the best color to maximize heat transfer to air.
 
@OP, what color is the motor now? Is it a dull or shiny finish?
 
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