The E15-2601 SPDT 240V Timer-Initiated Heat Pump De-Ice Control Provides Accurate Control of Temperature and Defrost for Heat Pumps. This Heat Pump Control Provides a 30, 45 or 90 Minute Field-Adjustable Timer Control for the De-icing of Heat Pump Outdoor Coils. Interlock Prevents more than 1 Defrost Cycle per Time Period and Temperature must be 28 F or Lower to Start. Unit has a 55 to 78 F (13 to 26 C) Temperature Range with a 5/16" X 5-1/16" Bulb and a 60" Capillary