Hello. I encounter a strange problem I'll try to explain simply. I've design 2 electronics racks that have only in common the mains network and the ground. These 2 racks are separated by a distance of more than 2 feet. In one rack in which are installed several high voltage power supplies, some sparks can occur. Each time a spark occurs in this rack an OpAmp (LM-324) installed in 2nd rack is definitely destroyed. How can we explain that ? I insist on the fact that except ground (connected to earth) there is nothing common to the 2 racks and only this OpAmp is burned other IC's and transistors (placed on same board) are absolutely not affected.