Defrost system controls are described as temperature initiated and

Defrost system controls are described as temperature initiated and

• A. Time terminated
• B. Temperature terminated
• C. Pressure terminated
• D. Humidity terminated

Answer: (B)

Defrost system controls are described as temperature initiated and temperature terminated because the cycle is driven entirely by coil temperature signals. A sensor detects frost buildup and triggers the defrost phase when the evaporator temperature reaches a frost-threshold. The cycle continues until the frost has melted and the coil temperature reaches a higher termination point, at which time defrost ends. This keeps defrosts responsive to actual conditions rather than running for a set time. Options relying on a timer, humidity, or pressure termination don’t fit this temperature-based control approach.

Defrost system controls are described as temperature initiated and temperature terminated because the cycle is driven entirely by coil temperature signals. A sensor detects frost buildup and triggers the defrost phase when the evaporator temperature reaches a frost-threshold. The cycle continues until the frost has melted and the coil temperature reaches a higher termination point, at which time defrost ends. This keeps defrosts responsive to actual conditions rather than running for a set time. Options relying on a timer, humidity, or pressure termination don’t fit this temperature-based control approach.