The MotorMaster is a fan speed control device activated by atemperature sensor. It is specifically designed to control condenserfan motor speed in response to the saturated condensingtemperature during operation in cooling mode only. For outdoortemperatures down to --20_F (--28.9_C), it maintains condensingtemperature at 100_F ± 10_F. The mounting control consists of a solid--state circuit on a printedcircuit board in an aluminum extrusion, and a sensor assembly tobe mounted to a return bend on the unit’s condenser coil. A wirefrom the sensor is connected to the circuit board in the control box.Parts necessary for mounting control and sensor assembly areincluded in the kit. Either assembly can be replaced independentlyof the other. If any damage to the printed circuit board orcomponents is observed when unpacking control assembly, returnfor replacement. The MotorMaster maintains proper condensing temperature atany ambient temperature down to --20_F (--28.9_C). No fieldadjustments or calibrations are required. Safety Standards California Prop 65 Yes Weights and Dimensions Operating Weight (lbs) 3 Exterior Dimensions (D) (inches) 9.000000 Exterior Dimensions (W) (inches) 8.000000 Exterior Dimensions (H) (inches) 5.000000 Shipping Weight (lbs) 3.500000