Shredder "Magically" Reverses Rotation, Why?

That's a wild one Dammit................good name. I don't know the answer, but I posted so I can be subscribed.

Welcome aboard. Just don't be screaming personal attack when people say, 'I already told you once Dammit, you're just not listening.'

It is also a new one for me... and I have been doing this a week or six.. I will let you and all know when we get it resolved.....

My thoughts as well. Will not be able to return to the location until Tuesday. Will swap contactors and re-terminate wiring at the motor at that time ( just in case there is a poor connection at the motor ) .

No reversing contactor in this situation. Good thought though..

On my list to check on Tuesday.... Thank You..

I remember my old foot-operated sewing machine, where an oscillation movement at foot board is converted in to rotary movement of a large wheel which then drive the machine wheel with a belt. The conversion mechanism from oscillation to rotary movement consists of a ball joint, a connecting rod and a crank. For running the sewing machine in forward direction, we have to move the machine wheel a little with hand and then foot pressure will work in that direction. But if we do not move the machine wheel by hand, then machine may move in any direction depending upon the angular position of crank before starting.

So, check whether you have similar mechanism with shredder. If yes, then it's no more a magic, just you have to check crank angle before starting.

Thank you for your response. The shredder is static until power is applied. I do see where you were headed. I will recall that for future reference.This unit is direct drive to the motor.

starter relay problem?

Straight shot from contactor. Relay would just spank the contactor coil. Gives me the thought to run an OHMS check on that coil. I have had some slow movers with poor latching due to a couple or few hundred more windings on the coil. I was in the coil manufacturing business once upon a time... we used to test 10 of every 100 that we made....if all 10 passed, the 100 passed. If one in 10 failed, they all failed...That was the routine back 30 years or so ago. Thank you for reminding me that Quality Control is only as good as the parameters set by the manufacturer..

An UN-shredder! An UNDO machine !!!!! The possibilities stagger the mind!!! Kinda' like a " do over " when I was a tadpole... I do like where I have arrived, but I do wonder where I would be had I taken the path to the left in lieu of the path to where I am.... I think that is what you try to teach the folks that are close to you..... " Learn from my mistakes "..... In my case, when they don't, I do have the option to say " I told you so "..

Seriously, though, the problem is very intriguing, since the 3φ supply hasn't been changed by the utility since the pump is running ok. i am looking forward to your findings ....

I look forward to the resolution as well.. I am like a dog chewing on a bone with a problem that I cannot solve.. I will not resolve the problem WE will! CR4 is an extreme resource.... I thank you and everyone in Advance for the assistance...

Dammit, I agree. Huge potential here. Do NOT change anything..... Put it on Ebay immediately

There is one possibility; very high harmonics on power line. Check for power line harmonics using Fluke-434 or similar instrument.

I am only semi-familiar with harmonics.. Both the pump and shredder are fed by the same breaker. Can one unit be affected and the other one not due to harmonics ??( Assuming that harmonics are only related to the source of power ) If so, what would be my cure ??

GA. Some thing different, could not be thought of by others.

Yes. Only one load may effect. First do confirm whether harmonics are present on your power lines or not. Solution depends on analyser data; what harmonics are present, ITHD, VTHD values, dominant harmonic numbers, etc.

I am just subscribing to hear the solution, it is intriguing!