Transformer keeps blowing!!! got me stumped...

Si-Woz-Ere · Jul 4, 2012

Hi there, would really appreciate any help here. I have installed two under unit kitchen lights, the long bar style with 3 lights in it with transformer concealed inside. The circuit they're on wasn't done by me. Customer also wanted dimmer on them which I installed for them. The under unit light on the right has never been a problem although it does buzz. the one on the left blew it's transformer. I replaced the unit like for like and the same thing happened again a couple of weeks later. I replaced it for three puck style lights with a seperate 20-60VA transformer. Transformer blew again a couple of weeks later. Replaced the transformer with a better one but again it's blown. The voltage it's getting is 220V though the dimmer when it's totally undimmed and the transformers being used are all dimmable. Again the one on the right has never been a problem.

Any advice?

Thanks.

malcolmsanford · Jul 4, 2012

Could there be an issue with heat build up that is not there for the one on the right

Si-Woz-Ere · Jul 4, 2012

I can't see why as it's pretty airy where it is and there's no other heat source around it?

thefish · Jul 4, 2012

Are you sure they should be on a dimmer?

Si-Woz-Ere · Jul 4, 2012

The transformer that was last installed is definitely ok to be dimmed as i use them all the time.

topquark · Jul 4, 2012

The minimum output for the transformer is 20W(VA) what power is being used when the unit is fully dimmed, I bet your dropping below the minimum output threashold and blowing the transformer.