A modern and high performance range of semi-hermetic compressors for refrigeration and air conditioning systems. Tandem design is particularly suitable for cooling systems with high capacity and an unsteady heat load. Tandem compressor allows both the control of large refrigerating capacity (particular feature of parallel compressor cooling system) and the easy design of single compressor system. It consists of 38 models with displacement from 49.38 m3/h to 411.60 m3/h with 50 Hz (from 59.26
to 493.92 m3/h with 60 Hz).

Electric motors

Pages 26 and 27 “Electrical data” feature the electric characteristics and performances of the whole range of available motors. For different voltages, please contact our Technical Dept.

Standard equipment

The compressors are supplied with suction and discharge valves (sweat connections), rubber vibration absorbers, oil lubrication charge, nitrogen charge (1 bar) to protect them against humidity, pressure connections, oil sight glass, electronic module for thermistor control, discharge gas high temperature control module, . They are coated with anti-rust protective primer and blue enamel coat. On request, compressor can be supplied complete with discharge manifold, suction pressure equalizer piping, oil pressure equalizer and muffler.

Higher efficiency with design, distinguishing the piston-valve plate assembly, is the final result of close research in order to reduce clearance, the most important reason of compressor efficiency loss. To considerably restrict such efficiency loss, FRASCOLD has shaped the head of the piston so that it matches suction valve reed profile. In the compressor with design, contoured piston lower cylinder clearance and an increase of capacity it results respect to the performances of a standard compressor.

Refrigerating capacities

Compressor performances are calculated at the operative conditions quoted on page 7 "Refrigerating capacity".

Electrical protection

For all compressors, protection is performed by means a series of PTC thermistors placed into the stator winding of the electric motor and plugged to an electronic control module (KRIWAN INT69 for QQ and SS compressors and model KRIWAN INT 69 TM for VV, ZZ and WW compressors). VV, ZZ and WW series compressors are supplied with discharge gas high temperature protection composed of two PTC thermistor sensors plugged to the electronic control module. PTC thermistor sensors are supplied on request for QQ and SS series compressors.

Lubrication

For compressors of QQ and SS series, lubrication is carried out by centrifugation with an oil thrower disc. VV, ZZ and WW series compressors lubrication is performed by an high pressure oil pump and equipment includes oil filter, oil pressure connection and universal bracket for oil pressure switch mounting.

Capacity control

Upon request, compressors can be equipped with electromechanical capacity control device. Refrigerating capacity reduction that results by one electric motor stopping and one or more device installation is shown on page 34. For LBP application, compressor with device has to achieve the application limits shown in the manual