Electrician's Licensing Practice Exam

What is the purpose of the two hot wires in a four-wire dryer system?

1. Balancing the load

2. Operating the light

3. Powering the heating element

4. Providing backup power

The correct answer is: Powering the heating element

In a four-wire dryer system, the two hot wires serve the important function of powering the heating element. This system typically operates on a 240-volt supply, where each hot wire carries 120 volts, and when used together, they provide the necessary voltage for the heating element to generate heat effectively for drying clothes. By utilizing both hot wires, the dryer can achieve the higher voltage needed for the heating element while also allowing for effective operation of the motor, which can usually run on a lower voltage. This setup not only ensures that the dryer can operate efficiently but also helps in balancing the load across the electrical system. Understanding this configuration is crucial for safety and efficiency in dryer operation, as it ensures that both components of the dryer – the heating element and the motor – can function correctly without overloading the circuit.