it would help if you studied the data sheets, a typical 230Vac MOV will start to conduct real current at about 700V peak...
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As shown your S10K25 MOV will start to conduct at about 30VDC as the Vac in goes above this the current will rise, the dissipation will eventually raise the temp to the point where the MOV breaks down at lower and lower voltages and then goes short and possibly then open if sufficient current available from the source for a good blow up ...