Hi
The below Power Supply Circuit is a part of Control Panel. the panel is manufactured in USA and installed here India in various locations.
The Metal Oxide Varistor MOV1 and MOV2 burns out on couple of panels and on one panel even LM2576HV blown out.
The MOV is SMD TYPE Blue Color chip after searching i found look similar is Liitle Fuse Make CH Series Varistor.
i think the panel manufacturer is using 40Vrms Metal Oxide Varistors since the Transformer secondary is 36V.
Input 230V is connected through surge suppressor in some case with out surge suppressor
i suspect that if the Input 230V more than 250V the secondary voltage go close to 40V of MOV then the smoke starts
but how the MOV1 and MOV2 burns out Not MOV3
any other reason for MOV1 and MOV2 to Fail??
P.Ashok Kumar