I have a (fairly old) Whirlpool fan oven, which turns itself off and trips all of the electrics in the kitchen when the oven reaches a certain temperature (around 150). If we then reset the trip switch and turn the oven down everything works again, and as long as temperature is kept below a certain point the oven stays on. The hob and grill all seem to work fine. Does anyone have any ideas?
Most likely the fan motor is bad and is factory set to come on at 150... pre-baking temperature.
My guess would be an underrated circuit, not a short-circuit. The amount of power used (and therefore amperage pulled) by an oven is linearly-proportional to the amount of heat it generates. Thus, if the circuit was underrated, it would trip at nearly the same temperature every time.
What is the amperage-rating of the oven, and of the circuit? Also, are there any other devices on the circuit (by code, the oven should be the only one)? You can check this by turning off the breaker, and making sure all the devices/outlets in the kitchen/nearby rooms still work.
It is one of three things:
- The blower's circuit is mis-wired within the range.
- There is a defect in the blower.
- The building wiring is not adequate.
If there has been a change to the range's internals since it worked well—like replacing the blower—it is likely it was not done correctly. For example, the thermal sensor may be bridging the power feed directly to ground instead of to the blower.
If the blower used to draw 75 watts but now, for some reason (loss of lubrication), it now draws 1000 watts, and the new total is more than the main can handle, it would completely explain the symptoms.
If you have recently added an appliance or other electrical load, maybe now the sum is too much for the service. Alternatively, perhaps the main breaker has weakened and now trips at, for example, 85 amps instead of its rated 100 amps.
There is a short circuit created when it reaches the temperature, either wires, of the heating element itself is faulty. It difficult to say without inspecting the wires, elements and everything closely really.
Since it trips your circuits, then its a fault and not a safety measure(like overheat switch) so be careful, or better yet, don't use it any more