MHA

Range: 23÷309 kW

MHA is the HiRef range of air cooled liquid chillers that uses a combination of Scroll ON/OFF compressors and modulating BLDC (Brushless DC-inverter) compressors. The excellent ‘configurability’ of the range in terms of refrigerating circuit, noise levels and available power ratings, together with the numerous accessories and options, make MHA chillers highly versatile and suitable for a wide range of system applications. The control software built into the MHA range lets users control the cooling capacity, delivered by Scroll ON/OFF compressors combined with modulating BLDC compressors, according to a dual logic: maximum power for fast achievement of set-point conditions and maximum efficiency to minimise running costs DC-inverter compressors are frequency modulated: from an electrical viewpoint this significantly reduces the inrush current. Users can select – according to unit size and specific plant engineering requirements – refrigerating circuits with different EFFICIENCY PACKS that ensure the system is redundant and/or efficient at low loads. The special component layout, together with compact plate heat exchangers and Scroll compressors, allows for generous condensing sections and for Free-Cooling enough internal space for fitting a wide range of accessories and hydraulic options. The Free-Cooling versions can be selected with the Glycol-Free kit (on board the unit) to confine the water-antifreeze mix inside the finned coil pack. This solution maximises heat exchange efficiency at the evaporator with the exclusive use of pure water; it also drastically reduces pumping costs. A precision hot wire flow switch (up to 1/10 of the nominal flow rate), together with a pump that is modulated via the control software, optimises water flow at all points and reduces the amount of power absorbed by the hydraulic module, thus preventing the risk of ice forming in the evaporator. TECHNICAL CHARACTERISTICS ON/OFF Scroll compressors combined with BLDC modulating compressors Refrigerating circuit types: – EFFICIENCY PACK 1: dual compressor on dual circuit for high system redundancy. – EFFICIENCY PACK 2: dual compressor (tandem) on single circuit for greater efficiency at partial loads. – EFFICIENCY PACK 3: three compressors (trio) on single circuit for greater efficiency at partial loads. – EFFICIENCY PACK 4: four compressors (dual tandem) on dual circuit, for a system that is simultaneously redundant and efficient at low loads. Electronically controlled expansion valve as standard Braze-welded stainless steel plate heat exchangers Programmable microprocessor control with dedicated software Variable flow control up to 25 % of nominal flow Second set point on utility side able to be activated from external input External temperature probe for set-point compensation Optional EC electronically commutated fans