Gas Fitter Practice Test

A fan control is a:

1. Normally open temperature control that closes on temperature rise

2. Normally open temperature control that opens on temperature fall

3. Normally closed temperature control that opens on temperature rise

4. Normally closed temperature control that opens on temperature rise

The correct answer is: Normally open temperature control that closes on temperature rise

A fan control functions as a temperature control system that is typically designed to activate a fan when the temperature in a specified area rises above a certain threshold. In this context, when the temperature rises, the normally open temperature control closes, thus completing the electrical circuit that powers the fan. This operation is designed to help cool the space by circulating air. This mechanism ensures that the fan only runs when necessary, thus providing efficient cooling and energy usage. The terminology “normally open” indicates that in its default state (when the temperature is below the threshold), the control does not allow current to pass through, keeping the fan off. However, once the temperature exceeds the predetermined limit, the control closes, allowing current to flow and the fan to operate. The other choices present variations of temperature control configurations, but they do not accurately describe the fan control's typical operating mechanism. The focus in this context is on the fan's activation related to rising temperatures, which aligns with the definition as provided in the correct answer.