From the following, choose the statement that reflects heating when 115VAC is present.

• A. The drain masts heat whenever 115VAC power is applied to the controller, regardless of the ON/OFF state.
• B. The drain masts heat only when the ON/OFF state is ON.
• C. The ON/OFF state governs heating when 115VAC is present.
• D. The drain masts never heat.

Answer: (A)

Heating is driven by the presence of the 115VAC supply, not by the ON/OFF control. In this setup, the drain masts have a heater that is energized whenever 115VAC power is applied to the controller, regardless of the switch position. That means the masts heat whenever power is present, to keep them from icing or condensing, even if the ON/OFF control is off. The other statements imply the heater only runs when the ON/OFF is on or never runs, which doesn’t match this wiring where the heater is tied directly to the 115VAC supply.