I have a C-Charger 1230A which recently ceased operating. After opening it up and removing the cover I discovered a melted white wire coming from the transformer to the DC bus. Easy enough to fix but I can't figure out the cause. Does anyone have a guess? Would a shore power surge cause this? I am on a 30 amp service and I don't have much protection other than a 30amp fuse between the SP and charger. Thanks.