I got called out to a customer’s site where an OEM piece of equipment showed up with older ABB motors on it. They are IE2 efficiency, but that was not the issue. Some of the motors were low-mounted (waist-high) with the shaft facing downwards. The fans on the back of the motors had plastic fan covers. The fans covers, if pressed, would dig into the actual fan of a rotating motor. (I did this with the back of a broom handle— do not try this at home kids!)

I mean, industrial machinery is dangerous. If we think about the Steven King story called The Mangler, with the industrial sheet folder that became possessed, we can get a grim glimpse of the possibilities. As engineers and designers, we go through risk assessments and design reviews for safety. We run safety validations and an abundance of other criteria to make sure folks are as safe as possible.  And in this case, you have a situation that if someone used the back of this motor as a ledge and rested their hand on it, they would come back with a severe cut— or worse.

ABB FPU motor with hazardous plastic fan cover

What Happened?

ABB offers plastic fan covers as an option on some motor sizes.  In this case, the OEM either choose the less expensive option or some other reason ranging from negligence to availability. We were able to simply order the proper metal covers and fix the problem.


OEMs are run by humans.  I do not believe this situation was sinister in anyway.  Someone obviously thought the plastic cover was good enough but the safety factor was not thought through. The plan B was to have a machine shop craft new covers, which we have done before.  Easy fix!

Tolbert DOE