The transformer lent to me by the housing warehouse will only work with two-prong plugs. If I plug in a grounded cord of any kind it trips the transformer and I have to reset it. Every time I reset it, it does this. Housing gave me two transformers and both of them do this. It's not the fuses because I can plug in an ungrounded plug and it works just fine when I reset it. Has anyone else had this problem?