Final answer:
A double pole breaker in a split bus electrical panel is used to control the 240 V circuits by interrupting excessive currents and preventing thermal overload. It plays a central role in ensuring safety in high voltage applications within a residential setting.
Step-by-step explanation:
A split bus electrical panel uses a double pole breaker to control the 240 V circuits. Circuit breakers and fuses are critical electrical safety systems that protect against thermal hazards by interrupting excessive currents. The use of circuit breakers, such as a double pole breaker in a split bus panel, is to manage circuits that require higher voltages, commonly 240 V in residential applications which often power large appliances or equipment. The breaker serves to protect the circuit by opening the circuit if the current exceeds the breaker's rated capacity, thus preventing potential overheating and fires. It's important to understand that circuit breakers are designed to be reset after they trip, unlike fuses which need to be replaced.
In the context of a three-wire system, this focus on managing 240 V circuits is consistent with the goal of preventing both thermal and shock hazards. The configuration includes live/hot, neutral, and earth/ground wires, with the neutral and appliance case grounded to help ensure safety. The double pole breaker hence controls the power flow in the higher voltage circuits, preventing unwanted thermal overload.