The patented ASU system has now been available for more than 20 years and has been installed on tens of thousands of boats worldwide. The ASU system starts the compressor when the engine is running and the power is available to freeze the holding plate completely. The energy stored in the holding plate will keep the refrigerator cool for many hours. When the engine is stopped, the compressor will not restart until the cold stored in the plate is all consumed. Once the stored cold is completely consumed, the compressor starts to run for short periods to maintain the required temperature in the box. With its unique principle of operation – the patented ASU “Automatic Start Up” system – Isotherm ASU has an important competitive advantage over traditional refrigerators.
ASU – Automatic Start Up
This unique system is designed to start the compressor up to 75 % of its performance mainly when the engine is running and plenty of power is available. Using a powerful compressor (a three-phase compressor with full-range speed control) is highly recommended as it achieves a quicker freezing of the holding plate. By taking advantage of the surplus energy generated by the alternator when the engine is running, the ASU feature does not reduce the engine’s effectiveness.