Magnet belt maintenance gone wrong

[chris kennedy]

Got a call today that a OL relay for a conveyor motor was tripping. This conveyor belt travels around an electro magnet which obviously sucks up the ferrous metals then slings them into a bin.

This conveyor belt came covered with stainless steel plates for protection. Motor showed normal current until I put power to the rectifier then it shot up to 8A over the OL relay setting.

I was baffled to say the least. Turns out the facility guys changed out the protective plates over the weekend and used steel instead of stainless.

So the magnet was creating a breaking action on the belt. Oops!

 

[ActionDave]

Everytime the motor isn't working an electrician gets a call and 90% of the time it ain't the motor.

 

[Jraef]

Yeah, big oops... I can just hear the thought process;

"We don't care if it rusts... go ahead and use hardened steel plate, it will last longer."

I had a similar one on a separator for a concrete recycling system, so it was removing rebar chunks after they went through the crusher. After the SS plate wore out, they replaced it with aluminum. Lasted about 2 days getting beaten to death by chunks of rebar...

 

[Besoeker3]

Everytime the motor isn't working an electrician gets a call and 90% of the time it ain't the motor.

Ain't that the truth................