could be your transformer is the wrong one,check the power rating eg 100w,this is the max power of lamp you can use on it,or your lamps are the wrong voltage.
jed, November 2010
Just two possible reasons
Manufacturing fault - a weakness inside - but more likely...
Too much load placed on it - trying to draw more power (Watts) than the transformer is rated for - it gets warmer and warmer and a wire inside melts.
Transformers are very simple and very efficient devices with often just two coils of wire .
