Hi friends,

Thanks for your replies & sorry for not replying early. We were meeting few academic people personally for the same problem so I could not answer.

It seems from your replies that we are facing this problem because of the EMC. But after discussions with above said peoples we are coming to a conclusion that it is an ESD problem.

Supporting evidances:
1. the problem increases with dry & cold air (more in winter than in monsoon).
2. If the other end of the wire (to be cut) is earthed the problem vanishes.
3. We soldered the already cut wire on this machine & made a long wire which has soldered joints at an interval of 1mtr. Using such wire to process again the machine never hangs.
4. we tried to increase the load on the motors by stalling them while in motion. but this does not hang the machine.


here are the answers to your various questions:

Q. Steve M. Taylor

Ans:
Yes, the machine runs for all the set length & diameters, for hours if the wire is not cut. we have passed few hundred meters of wire without cutting (cutters off) & it runs troublefree.

this proves the machine logic is ok.

Q. Raghunathan R

Ans:
1. The tree ground is the same as star ground. this is proper seperate earth for this machine & not the neutral.

2. the diodes are high speed diodes.


Q. Steve M. Taylor
Ans:
Proper snubbers are already on the drives.

We have used RS485 for communication, but failed(the machine hangs).

we are trying to give you more information on this issue.

Regards,
Prashant