O Gauge Jim posted:...From the looks of your pictures it appears your transformer has seen some very high currents for an extended period of time... I am guessing your circuit breaker was not working properly and a short circuit current occurred And the circuit breaker did not open.
My guess based on the pics is that "A" was set to about 7 volts and "B" was set to 13-14 volts and then something connected/shorted the two together. There is no circuit breaker in the KW to prevent this.