9A current inside conductor

Status
Not open for further replies.
PT said:
As per your diagram, the center of your wye is connected to ground, it is not also connected to to the load? You have a capacitor bank, that can also be factor in your mystery current.
Some drives are very sensitive, sometimes we install AVR or TVSS to protect them from over-voltage.
Click to expand...

finally we open up the transformer, see how it is connected internally.
here it goes:
-ground conductor fed from Motor center, to capacitor bank, to transformer primary(delta)side.
-ground conductor then goes through lug (that is clamped down on bottom of transformer frame), then go as continuous loop through the wye center (X0 of secondary side)
-then continue going to the electrical panel with 6 insulated conductors (L1,2,3, shown in picture at the beginning of the posting).

-overall there is NO NEUTRAL wire in the electrical panel. there are single phase motors connected across L1,2, or l2,3, or l1,3.

would drives be affected if capactor bank is on the primary side of transformer, and drives are part of derived system?

I have to admit that I am puzzled... where about that most likely find the line to ground fault? what cause the overvoltage (paths).
 
I think petersonra said it right, if your e-stop is just a disconnect switch between the drive and the motor, and not apart of the drive controller, you should not be using it on a normal basis. As petersonra said the energy has to go somewhere. You will continue to damage your drive if it configured this way.

The computer system I use prevents me from looking at your diagrams, so pardon this post if not applicable
 
Hi Plate
hopefully you can read out of this diagram
transopen01C6743524380042.jpg


it shows the latest test result.
it shows 1A (sometime 47ma)current in the bare conductor, when L1,2,3 is off. I need help to understand if current is from line side? and ONLY transformer source? or from load side???

petersonra said it right...e-stop is just a disconnect switch
Click to expand...
thank you for mentioning about petersonra's points on braking, definitely I will review petersonra's post, and reply.
 
I think I'm getting the picture. Someone please correct if I'm wrong.
There's a good possibility that your mysterious current is coming from the grounded delta primary, and is affecting your drives in the secondary. Try connecting a grounding electrode conductor on the first disconnecting means of the secondary side so that you will have a separately derived system. This might free the secondary side, wherein your having problems, of any abnormality on the primary. And if possible, start your neutral from that point and lay it out on that system to serve your line to neutral loads. Be sure to have no other bonding of neutral to equipment grounding aside from the first disconnect means.
 



This is what I was suggesting you do. This installation give you a separate derived secondary.
 
Status
Not open for further replies.
Top