BITZER has optimised its tried-and-tested CR capacity control system by adding blocked suction, and showcases the high flexibility and exceptional reliability of its new CRII system at Mostra Convegno. The heart of the CRII system is the newly constructed control piston with a hollow -design, which facilitates an extremely high switching frequency.
‘With its CRII system, BITZER offers its customers a whole new level of flexibility and the option to adjust ECOLINE compressors in line with operating conditions,’ explains Volker Stamer, Director of Stationary Products at BITZER. ‘This increases efficiency, whilst protecting the environment and saving money.’
Depending on the operating conditions and refrigerant, a special control algorithm allows compressors to be infinitely adjusted. With the CRII, BITZER has achieved an exceptionally wide range of control between 10 and 100% for four and six-cylinder compressors. The increased switching frequency on the other hand ensures smaller fluctuations in controlled value, temperature and pressure and, in combination with the expanded range of control, optimises system efficiency. As a result, tandem compressors can even be reduced to 5%.
Compressors are also available with the CRII cylinder heads pre-installed. The CRII system is backward compatible and is available for the ECOLINE with a capacity range of four to eight cylinders. All the cylinder heads in the ECOLINE compressors 4FES-3(Y) to 6FE-50(Y) as well as the two external cylinder banks in the compressors 8GE-50(Y) to 8FE-70(Y) can be retrofitted with CRII.
Manufacturers CAREL and ELREHA offer controllers
CAREL, an international company specialised in electronic control solutions and components for the HVAC&R industry, already launched the pRack pR300, a cutting-edge compressor rack controller featuring the innovative CRII system, at the EuroShop 2014 trade fair in Düsseldorf in mid-February. In addition to the already available integrated BITZER screw compressor management system, the pRack pR300 controller now allows one to take full advantage of the CRII system, explains Nicola Pieretti, Retail Application Specialist at CAREL. Upon selecting the right compressor model for the integrated wizard, the pRack pR300 will automatically load all settings needed for a seamless unit start-up and correct management according to approved BITZER specifications.
Manufacturer ELREHA has also developed a new MSReco 3130 controller for use in conjunction with the BITZER CRII system. The control device is scheduled for release at the end of May.