D.C. drives tripping problem

i am working as an electrical engineer in a continuous galvanising line which is run to galavanise sheets of thicknesses varying from .3 mm to 2mm We are facing a peculiar problem in one d.c. drive which is used as a speed drive in the process section.The process line uses 15 d.c. drives in all of which four are speed drives . a drive just before the concerned drive is also a spped drive.The drive trips on

 

[umn]

Dear Jayantpn,<br>
Couldn't see the whole problem statement- could you please make it briefer?

 

[Madhusudan]

question not clear jayant, can you come again