Hi I'm new here and I just would like to ask for help regarding our surge suppression system. Our surge supression system is designed to eliminate transient voltage spikes on the 3 phase AC lines to protect the SCR pucks on the scr system. The surge supression system consist of a 3 phase bridge rectifier connected across the 600 Vac line, and on the output of the bridge rectifier is the 2 each DC capacitors, rated at 800 Vdc, 10 MFD, and a Resistor Bank. As explained in the user manual, when a voltage transient occurs, that would normally appear as a spike on the ac waveform, it is absorbed by the capacitors as the spike attempts to raise the capacitor voltage. The small voltage increase over the initial voltage stored in the capcitor will then be 'leaked away' by the discharge Resistors. The situation is this; The 2 DC capacitors have been replaced with AC capacitors rated 1,100 Vac, 10 MFD. and we still face the problems of replacing scr pucks as well as MOV's across them several times in a year. My question is this: Do the AC capacitors used in place of DC capacitors serve their purpose the same? If they are, could you please suggest why we are still having pucks and movs failure?