Refrigeration compressors, as used across the food and drink industry, can suffer severe damage following start-up after a power failure as a result of stepper valves being out of sequence and in the wrong place.
This can lead to liquid refrigerant entering the compressor crankcase, resulting in low oil pressure and possible failure. Resultant damage can shorten compressor working life or may be so serious that it requires complete replacement, representing a huge expense for end users.
Recognising the problem, RDM has developed the Intuitive Power Store which links to the company’s stepper valve controller, to provide protection against compressor damage on start-up following power failure.
The combination automatically closes stepper valves when mains power is lost. “It is effectively a mini Uninterruptible Power Supply (UPS) with a brain,” says Andrew Chandler, md of RDM.
In the event of mains power loss, the Power Store provides the energy to enable the stepper valve controller to accurately control the setting of the valve to a fully closed position. When mains power is restored, stepper valves are then returned to the correct operational settings gradually, in line with the evaporator duty required.
This means that the compressor is not hit with a large and unpredictable load before it is fully up and running, and in a safe operating condition to respond.
“Power outages are by no means uncommon, for all sorts of reasons. The cost of replacing compressors can be very significant for end users. The new RDM system gives refrigeration users the vital protection they need, and provides the opportunity to control system restart to ensure cooling power is delivered to where it is needed – while minimising the impact and potential damage on refrigeration plant.”
The company points out that the combination of Intuitive Power Store and stepper valve controller represents a fraction of the price of a compressor.
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