USA: Johnson Controls has expanded its Penn 450 series of modular electronic refrigeration controls with the C450CCU, a unit combining temperature, defrost and fan control.
The System 450 C450CCU digital electronic controller is the newest member of the System 450 series of modular electronic controls for managing the space temperature of small and medium capacity walk-in coolers/freezers and refrigerated display cases.
The C450CCU controller accepts up to three sensor inputs. Two of these inputs are temperature sensor inputs; one for sensing space temperature and the other for sensing evaporator temperature. The third is an input for pump-down control by sensing system suction pressure.
The controller includes passive, off-cycle defrost, or active, electric heat defrost for maximum efficiency. Depending on the application, defrost cycles can be terminated based on time or evaporator temperature.
A built-in fan delay switch enables single or two-speed evaporator fan control.
Applications in cold weather climates can take advantage of the optional pump down control feature. This prevents liquid refrigerant from traveling to the compressor during start-up.