Control System Function and Operation
EDS55-801
Tolerances of about ± several °C in the set temperature value is sometimes expected against the actual input of current value.When the temperature has been set from the external analogue input, please make a final check of the set temperature seeing the display on the main body control. 5. Range of temperature setting Temperature setting display range. Cooling 4 ~ 30°C (outlet water temperature setting range for 4 ~ 16°C ) Heating 25 ~ 60°C (outlet water temperature setting range for 35 ~ 55°C) Yardstick for making temperature setting. For general cooling, use the below settings. Chilled water setting
Hot water setting
7°C
45°C
Note: Set the temperature so that outlet water temperature, whichever selected for temperature control, stays within the set range. If the temperature is set too low or too high, the high pressure switch or the temperature switch (freeze protection) might trip. 6. Operation of the pump while the operation of the chiller has been stopped In order to prevent the unit from freezing during winter, the unit is equipped with a function to carry out an automatic operation output of the pump when the water temperature becomes lower than a specific temperature even while the chiller has been stopped (when the water temperature at the outlet of water heat exchanger in the chiller is lower than 3°C.) Do not fail to carry out wiring so that the pump may be operated in accordance with the pump operation output from the unit. 7. Low noise operation during night It is possible to use the unit by lowering the fan noise by stopping some of the fans when the ambient temperature is relatively low, for instance, during night. For details of setting, please refer to [local settings on the control panel]. By controlling the maximum load of the capacity of the compressor at 70%, the number of the fans to be operated is reduced to its half. When the ambient temperature rises and the high pressure increases during operation in this mode, all fans start rotating to prevent the pressure switch from actuating (protection for high pressure). When you perform a low noise operation during night, carry out a wiring of no-voltage normal contact-A input between the terminals Nos. (30) and (31) located in the switch box. When the contact input is ON, the mode becomes low noise operation during night. When it is OFF, the mode becomes normal operation. This function is made possible by external contact input and cannot be set from the remote controller or centralized controller. 8. Demand operation control A demand control by means of running current of the compressor is possible during remote operation of the unit. (Refer to NOTE) 1 and 2.) By demand control, the capacity of the compressor is controlled in such a manner that the set current value becomes the upper limit. In the case of sending a demand operation instruction from the remote controller: Start the demand control by pressing the DEMAND CONTROL button on the remote controller. The demand operation control needs to set the local setting No. 7 to [0:remote controller].(Refer to [local settings on the control panel].) For detailed operation, please refer to [How to set demand control]. In the case of sending a demand operation instruction from the external contact input: Start the demand control by turning the contact input (no-voltage normal contact-A) between the terminals Nos. (32) and (33) ON. The demand operation control needs to set the local setting No. 7 to [0:remote controller].(Refer to [local settings on the control panel].) For detailed wiring, please refer to the [Electrical wiring diagram]. Setting of the current for demand control: Carry out the input operation of the current for controlling the demand from the control panel. (Refer to NOTE) 1 and 2.) For detailed operation, please refer to [local settings on the control panel]. If you want the thermostat to be OFF (to stop the compressor and fan) while inputting the instruction for demand operation, input the set value of the current for demand control as 0A.(This has been set at 0A when the unit was shipped out from our factory.) Under above setting, if you try to input the instruction for a demand operation during thermostat ON (during the operation of the compressor and fan), the thermostat turns OFF.When you have input an instruction for a demand operation while the thermostat is OFF and the chiller is stopping, the thermostat does not turn ON 98
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