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Today, the HVAC system components are spread throughout the engine compartment, exposing them to high heat and vibration. The automotive alternator and HVAC components are often among the top miniature five product reliability issues cited for both construction equipment and on-highway trucks.The newly hydraulic developed MorElectric HVAC module system combines all the HVAC components into a new module that uses an electrically powered, hermetically sealed compressor. "Packaging all the components together," Orr said, "also allows the use of rigid refrigerant tubing, and eliminates refrigerant permeation through the hoses. We expect to achieve a 5x improvement in reliability and a 3x improvement in durability over current air conditioning systems as used in trucks and construction pumps equipment miniature today." The HVAC module removes the condenser hydraulic from the radiator area of the pumps engine compartment, providing miniature more physical space, hydraulic as well as eliminating the air conditioning thermal load from the radiator air stream. Cat estimates its new modular HVAC also eliminates pumps as many as 65 parts. Field service thus becomes a simple replacement function. The module can be swapped out miniature in less than an hour, allowing customers to quickly get back up and running, and returned to revenue service. Controlling the Integrated Water-Recovery SystemIn this section, we describe the control tasks for the final IWRS system that went into test in 2001, first by subsystem and then for the IWRS as a whole (figure 8).The Biological Water ProcessorFeed water from the hydraulic waste-water pumps collection system (figure 3) first passes through the BWP. The main control task for the BWP is to keep the water in the gas-liquid-separator (GLS) (see the lozenge icon with the three-level switches in miniature the upper left of figure 8) at mid-level, which is accomplished by varying the speed of the feed pump, and the draw from the reverse-osmosis hydraulic main pump remains constant. The other requirement is to monitor the pressures in the recycle loop, as well as in the nitrifier tubes, and carry out automatic shutdown procedures in the case of off-nominal values. For example, if one of the nitrifier tubes shows too high a pressure, the water and air pumps associated with this tube are shut down, and pumps a warning is issued.
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