Central machinery 12x36 wiring issues help needed

At this point I would suspect a contactor or direction switch wiring error. It is difficult to see all the labels on the wires so diagnosing may be difficult. Most of the wires that I can easily see seem to match the basic wiring diagram with the exception that your contactors should be labeled k1 k2 k3 left to right. Good pictures of the switch wiring will help too.
 
Interesting that the contactor's are labeled backwards.I didn't know so I put them back how I replaced them. Im thinking someone swapped 1&3. Also on the old km2 contactor l1,t1 and l2,t2 were stuck. Maybe this helps to diagnose. I'll get switch photos tomorrow.
 
I think we might have to repeat some tests we did earlier because we should have caught everything by now.
Let me cogitate a bit on it- if the motor is disconnected and you can put it in forward and reverse without tripping the breaker
there is no way connecting the motor correctly should cause a trip- unless the motor still has a fault

There must be an internal motor short to case that doesn't show up at rest somehow- maybe has to do with your work on the internal switch that was stuck...wire touching the case? Mechanism shorting to the case? I've seen any and all of those happen at various times
Did you have a ground wire on it when you tested it earlier?

The 3 contactor machines usually have that lineup- KM1 is the primary power, KM2 is forward and KM3 is reverse
 
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markba633csi said:
Let me cogitate a bit on it- if the motor is disconnected and you can put it in forward and reverse without tripping the breaker
there is no way connecting the motor correctly should cause a trip- unless both KM2 and KM3 are trying to pull at the same time
but that should have shown up with the motor unhooked- check the motor connections again- shoot a picture
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This is what I am suspecting is that both contactors are being activated at the same time. That's why I am leaning towards a contactor to direction switch wiring error. Because he mentioned that the fuse to the motor did not blow I was thinking the motor was still connected when it was last tried
 
Ok ,So yes the motor was connected when the breaker tripped and the motor fuse did not blow so what im going to do is retest some things in prior posts,get a motor pic, check for motor short and show the previous and current switch wiring . hopefully that will get us in the right direction.
 
If the contactors were trying to pull at the same time then it would cause a trip with motor unhooked- pretty sure that ain't it.
We tested for that. We could test it again but I think the result would be the same
Always check the last thing you worked on which in this case is the motor centrifugal switch- must be a short- and not on the main leg
but on the start leg. Why? because it didn't blow the inline fuse- that's a clue
 
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RSnell said:
Ok ,So yes the motor was connected when the breaker tripped and the motor fuse did not blow
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markba633csi said:
If the contactors were trying to pull at the same time then it would cause a trip with motor unhooked- pretty sure that ain't it.
We tested for that. We could test it again but I think the result would be the same
Click to expand...
I don't think it was tested without the motor connected
 
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