So i get a call out ... small explosion in a machine ... the transfomer went up in smoke ... no fuse protection ... no cicrcuit breaker ... the machine has been working for a few years ... and no changes have been made to the wiring (as it is from China)

The part that still gets me ... 0-230-380

The transfomer supplies the controls and the coolong fan ... L1 - 380 (white wire) ... controls and fan connected to 230 (yellow wire) ... L3 - 0 black wire ... then to confuse you ... things like the thermostat are connected on the 0 volt side ... but the n/o of the timer and temp controller are connected to the 230 volt side.

I have figued it all out created a schematic diagram ... removed the transfomer ... changed the wiring ... connected a neutral from the 5 pin plug and it is working ... but still battling to get my head around the 0 v connected to L3 ... not something i would ever do or done in the past when designing and building electrical control panels.

I have googled and found a ton of info on auto transfomers and how they work ... and used to save money.