The iZ series was granted an award for excellent energy-saving equipment.
Since its foundation, KOBELCO has handed down its pioneering spirit as an inventor of screw refrigeration compressors. Always attuned to the voice of the customer, KOBELCO is driven by a strong sense of mission to develop refrigeration compressors that lead the industry and provide good proposals. Another superb piece of equipment has been created through the combination of this outstanding passion, vast experience, and advanced technology. iZ series is the world’s first two-stage compression screw compressor equipped with an inverter. By being equipped with an inverter, this “iZ series” now features a maximum cooling capacity that was never-before-possible in the history of refrigeration compressors, and outstanding energy-saving effects emerging from the control of rotation speed. KOBELCO “iZ series” has made a successful debut here.
Although conventional refrigeration compressors drastically reduce cooling capacity as evaporation temperature decreases, they are unavoidable. Focusing on the fact that the motor or capacitor generates available energy when evaporation temperature decreases, the “iZ series” exercises its capacity to the maximum extent possible by increasing speed for the amount of the generated available energy with the inverter. In addition, in 50 Hz areas where users are forced to settle for 20% less performance compared to 60 Hz areas, the “iZ series” can exercise the same capacity as in the 60 Hz areas. When the suction pressure saturation temperature is -40°C, for example, the “iZ series” can increase its capacity by approximately 20% in 60 Hz areas and approximately 40% in 50 Hz areas (Compared with our conventional model). Therefore, users can select our model one or two class smaller than other companies’ compressors.
monitor”KOBELCO decided that providing an alert only for an emergency stop is not adequate. The “iZ series” constantly monitors the running conditions of refrigeration compressors with sensors installed in various areas. With its ability to detect an anomaly in compressors in advance, the “iZ series” generates a warning before an emergency stop or a failure actually occurs and prevents a sudden machine-down. In addition, with its operation history storage function, the “iZ series” can identify and keep tabs on potential problems and enable quick trouble shooting.
The “iZ series” can smoothly control its cooling capacity by manipulating the rotation speed of the inverter in order to prevent excessive cooling for outstanding energy saving performance. Unloading performed by the piston valve was replaced with the control of rotation speed by the inverter to ensure optimum operation according to load. This allows for drastic energy saving. Users, for example, can reduce electrical power costs drastically, as indicated below (Our estimation, compared with conventional models):
This is a capacity control mode to smoothly control rotation speed within the capacity-controllable
range with the inverter by inputting signals according to the temperature inside the refrigerator and
other conditions in order to achieve an optimal temperature inside the refrigerator.
* Based on its reading and interpretation of signals from the inside temperature controller
or other devices, it decides the capacity level (max to min).
For operation in this mode, it is necessary to input a current signal of 4 to 20 mA according to the operation status.
This mode can perform the conventional control with ON, OFF, and Unload signals. The “iZ series,”
for example, can perform capacity control at 50%, 75%, and 100% steps.
* The 50% and 75% steps can be changed.
Users can change the setting according to the intended use.
The effect of an equipped inverter can be seen when the compressor starts. At a conventional star-delta
start, the motor bears a great load and needs an approximate 10-minute interval for restarting.
The “iZ series” does not need this interval due to the soft start by the inverter, and it can quickly restart.
With the “iZ series,” users can stop the compressor and use it for their desired purposes that were
not possible earlier. It contributes to energy saving and reduces the size of power-receiving equipment.
