How does a Condenser Fan Controller-SM420 work?

How does a Condenser Fan Controller-SM420 work?


Operation Description

On a demand for cooling, a 24v signal is sent to the SM420 which starts the condenser fan at 70% fan speed for one minute.

After one minute of operation and the refrigeration circuit will have stabilized, the controller will sense from the temperature probe on the Compressor 1 liquid line.

Once the temperature of the liquid line is above the low limit, the fan will modulate through the 0-10v dc output until it reaches the full speed temperature limit.

The temperature dials for the start speed –  low temperature and the full speed – high temperature are adjustable using a small screwdriver allowing finetuning during commissioning.

If Compressor 2 is required, the SM420 operates from Comp 2 sensor which is connected to the liquid line of Compressor 2.

On a demand for Heating, the SM420 switches to heating mode and the fan will operate from the speed pot which allows the fan will run at a fixed speed. Adjustment of this speed pot should be made at commissioning with gauges attached to the refrigeration circuit to maintain the bests possible refrigeration pressures during the heating cycle. The manual pot is set at commissioning in the factory and should not require adjustment on site.
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Disclaimer: The data and information contained in Armcor Air Solution technical specification sheets are representative of expected performance. They are derived from aggregated specifications of the individual components used in the equipment and not from verified laboratory testing. This should only be used for evaluating your specific application and clients have the sole responsibility of satisfying themselves that the goods or services are suitable for any specific use.