Identify the statement in which only the true heating condition is stated.

• A. The drain masts heat only when the ON/OFF state is ON.
• B. The drain masts heat only when 230VAC power is applied.
• C. The drain masts heat when no power is supplied.
• D. The drain masts heat whenever 115VAC power is applied to the controller, regardless of the ON/OFF state.

Answer: (D)

The heating is driven by the controller’s supply voltage, not by the ON/OFF control line. When 115 VAC is applied to the controller, the heating element energizes, regardless of whether the ON/OFF indicator shows ON or OFF. This matches the real wiring where the controller’s power is the condition that allows heating to occur. The other statements either tie heating to the ON/OFF state, to a different voltage (230 VAC), or to no power at all, none of which reflect the actual control path. So the statement that heating happens whenever 115 VAC is applied to the controller, regardless of the ON/OFF state, correctly describes the true heating condition.