This is getting ridiculous... No, that's just desperation!

desperation IS ridiculous, you do not fix anything, you just make matters worse when workig desperately.


but customer should not shout for stopping the machine. so some how i need to run the machine and mean while find a solution as suggested by you and all.

OK, temporary fixes:
1) Install .1uF CERAMIC capacitors DIRECTLY across EVERY Vcc and Gnd on EVERY chip on your board.
2) Insert ferrites in EVERY wire leaving or entering your board.
3) Move the relays that drive the contactors away from your board. (as a temporary, you can insert another relay (relay on board -> relay off board -> contactor).
4) Put your stuff in a grounded steel box

The talk has to stop, it is time for action. The above measures can be taken in a few hours (plus shopping time?), DO this, then come back.

Erik