A closely stepped range of compressors for modern refrigeration, air conditioning and heat pump systems.With its new BITZER ECOLINE series, BITZER offers high-efficiency universal compressors that satisfy the demands of modern refrigeration systems:extended range of applicationsenergy efficientcost-effective power regulationwear-resistant drive mechanismquiet and low-vibrationminimal space requirementsrobustBITZER ECOLINE compressors for operation with frequency inverters up to 70 HzAll BITZER ECOLINE compressors are designed and optimised for 70 Hz operation. Depending on the refrigerant used and the environmental conditions, a compressor with a PW standard motor (400 V, 3-50 Hz) can be used, or a special motor (230V/400V, 3-50 Hz*) may be required and connected in a delta circuit (230 V, 3-50 Hz). The latter is the case for compressors using version 1 and 2 motors where they are to be operated throughout the entire documented area.The use of a PW standard motor for 400 V or the connection of a 230/400 V motor in a star circuit must be discussed with BITZER on an individual basis due to the drop in the torque value when operating above 50 Hz (fig 1) � see also Technical Information KT-420.