Johnson Controls MR4DR24-12 Defrost Control Freon protecting the limit switches and

protecting the limit switches and thermal governors from overheating

and residential furnace models

the McDonnell & Miller 310452 is the current standard for Series 51 and 851 units

supporting capacities of 1/2 to 3/4 tons depending on the refrigerant and evaporator temperature

Johnson Controls MR4DR24-12 Defrost Control Freon protecting the limit switches andThe Johnson Controls MR4DR24 12 is a professional grade electronic temperature control designed for precise defrost management and multi stage HVACR applications. Operating on 24 Vac, this four stage controller provides exceptional reliability with a 1. 8 degree accuracy, ensuring tight setpoint maintenance in critical refrigeration environments. The unit features built in alarm management and is packaged with two A99BB 200C sensors, allowing for