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Resumen del manual
The switch returns to the normal status when the temperature increases over 41°F(5°C). The Anti-freezing switch is installed on the evaporator. Fig. 29 52 Chiller Air-cooled Screw Service Refrigerant Cycle Leakage test As described in the installation manual, the unit is sufficiently charged with R134a refrigerant as factory setting. If the refrigerant pressure is lower than the factory setting, you must check for leakage. If the pressure inside the unit has dropped, use the Nitrogen to do a leakage test. When repairing the leaking part, you must use good refrigeration practice. After the leakage is repaired, any water inside the chiller must be removed and vacuumed. Charging the refrigerant Insert the coupling to the refrigerant charging port. In order to avoid the damage to the tube from residual water freezing within the evaporator, circulate the water in the evaporator (EVA) while charging the refrigerant to the designated amount. For the amount of refrigerant to charge, refer to the installation manual or PDB. Charging the oil Insert the coupling in the oil port. Check whether the oil level is above in the Sight Glass window. Remove the coupling and insert the oil port cap. After inserting the oil, operate the product and check whether the oil level is above with the naked eye. If not, supplement the oil. Operation & Maintenance Manual 53 Service Refrigerant Cycle Oil Filter The oil filter is installed on the oil separator in oil return line to the compressor. Differential pressure between the inlet and outlet of the oil filter must be checked periodically. On the oil separator, the core valves for connection of the inlet/outlet with pressure gauge are installed. If the differential pressure is over 5kg/cm2 it is recommended to disassemble the oil filter and wash the oil filter mesh. Item Name Note Qty Bolt M10 x 40L 8 Service flange O136 x 15t 1 Gasket O90 x 1.5t 1 Spring O37 x 2d 1 Oil Filter Cartridge 30 mesh/inch 1 O-ring O28.24 x 2.62W 1 Oil filter Body O136 x 270L 1 Table 19 Fig. 30 Oil Flow Switch The oil flow switch is also installed on the oil separator in oil return line to the compressor. The setpoint range of the flow switch covers 3.4~4.2 l/min at increasing flow and 3.0~3.8 l/min at decreasing flow. Maximum flow rate of the oil flow switch is 67l/min. Fig. 31 54 Chiller Air-cooled Screw Service Oil Heater The oil heater prevents poor lubrication due to too low viscosity. The oil heater is also installed on the oil separator. The 150W oil heater has 220VAC power input. Fig. 32 Solenoid Valve One of the Solenoid Valve is installed between the Flash Gas Tank where the oil separator is installed and the other is installed between the oil filter and Flash Gas Tank. Valve on the compressor side is turned on during Full Load operation, and off during other operations. Valve on the oil filter side is turned on when the unit is operating to pass the oil to the compressor, and off when the operation stops to prevent the oil from back flowing. Include Cable wire Include DIN plug wire MODEL Connect H1 H2 H3 H4 L L 2 L 4 L 3 L5 max B B1 Max weight 10W 12/20W in mm mm mm mm mm mm mm mm mm mm mm mm mm kg EVR25 1-1/8 28 38 138 72 256 22 45 54 75 85 95 68 3.0 1-3/8 35 38 138 72 281 25 45 54 75 85 95 68 3.3 Fig. 33 Operation & Maintenance Manual 55 Service Control System The structures of the power panel and control panel are shown in the below. The power panel in the left is composed of the electrical components related to 400VAC main power, and the control in the right is composed of low-voltage components such as the PLC and the HMI unit. Both panels are designed to be water proof by dual door system. The panels comply with IP55. Control Panel Power Panel Fig. 34 56 Chiller Air-cooled Screw Service Power Panel On the left side of the power panel, terminal blocks for main power connection are prepared. The field supplied 400VAC main power lines and neutral line for control power are connected to these terminal blocks. There are three magnetic contactors for the wye-delta starting of the compressor and OCR (Over Current Relay) for the compressor. For wye-delta starting, there are three magnetic contactors installed inside of the power panel. By the wye-delta starter, the starting inrush current is reduced by 1/3 of direct starting method. The line voltage(VL) of the both of wye and delta winding configuration is 400VAC, but the phase voltages(VP) of the wye winding configuration is reduced by 1/3 of the delta winding configuration. Additionally, the line current (IL) is also reduced by 1/3 of the delta winding configuration. Consequently, the current of the wye winding configuration is reduced by 1/3 of delta winding configuration. Using the principle, the compressor starts with the wye winding configuration. And the winding configuration is changed into delta configuration after few seconds for the normal operation of the compressor. Compressor Wye-delta Starter Main Power Compressor OCR Fig. 35 ...