285. Refer to figure «A» representing an electric oven as shown in the illustration. With the oven turned on, the power available indicator light is off, the oven on indicator light is off, and only elements «6» and «7» appear to be producing heat. Which fuse is blown

The L1 10A line fuse is blown because the power available and oven on indicator lights are off, and elements 6 and 7 are producing heat; this indicates a loss of power on phase L1, which supplies these indicators and elements 1-5, while elements 6 and 7 are powered by phases L2 and L3.