KIDDE Fault

Hi all,

This is my first question or discussion, I work in a gas plant as an instrument engineer, the problem is we use F&G panel KIDDE ITALIA 1019 E control panel with different types of I/P and O/P cards and it used to be normally good but now it gives strange faults at least one per day, sometimes it isolate (override) all I/P and O/P points, sometimes gives faults on some cards in random way and sometimes isolate power of some cards also in random way, I checked wiring in TB and its good and in the field instruments are good, I checked the power and it is also good but I found that there is no earth connected between panel earthing bar and the common electronic earthing bar of the auxiliary room (not earthed) then I connect a new one but the problem still exist , I'm still trying to discover the reason of this faults but I have no service manual for troubleshooting, So please if anyone can help me or send me the service manual or have any idea to solve this problem I will be very greatful and I'm waiting to discuss this problem with any interested one,,,

Thanks alot,,,