Isotherm ASU charges the holding plate while the engine is running.
The patented ASU system has now been available for more than 15 years and has been installed on tens of thousands of boats worldwide. The ASU system always starts the compressor when the engine is running and the power is "free" to chill 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 energy stored in the plate is all but consumed. Only then will the compressor start to run for short periods to maintain the required temperature in the box. The ASU system always uses the stored energy first before automatically starting the compressor when the engine is running. With its unique principle of operation - the patented ASU "Automatic Start Up" system - Isotherm ASU has the advantage over traditional refrigerators.

ASU - Automatic Start Up
This unique system is designed to run the compressor primarily when the engine is running and plenty of power is available, making it preferable to have as large a compressor as possible to chill the holding plate rapidly. 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. The Isotherm ASU system increases the speed of the compressor up to 75% when the engine is running, to freeze the holding plate rapidly and effectively. This can only be done by a three-phase compressor with full-range speed control. The "intelligent" microprocessor is useful even when running only off the battery. If, for example, a crate of warm beer is placed in the refrigerator, or its door is inadvertently left open, the ASU function will speed up the compressor just enough to keep its contents cool. For larger refrigeration requirements and greater energy sources, Isotherm TWIN ASU is a good option. The Isotherm Twin system expands the refrigeration range from one compressor running at low speed to two compressors running at high speed. With both brain and brawn, Isotherm automation turns on full power only when it's required - and
available!

Isotherm ASU - perfect for solar panels and shore power
The ASU function senses when only a small amount of current is being produced by either a solar panel or battery charger and registers the difference between this trickle charge and the shorter but much higher charging level produced by the
engine's alternator. In this situation the holding plate is charged slowly and at a rate consistent with the energy being produced by the power source.

Indel Webasto Marine USA Inc, 3400 Gateway Drive, Unit # 107, Pompano Beach, FL - 33069 USA Phone (954) 984-8448 Fax (954) 979-2533 Email info@indelwebastomarineusa.com