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Midea LSBLG365/MCFN Technical & Service Manual

Flooded type water cooled screw chiller
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Flooded type water cooled screw chiller (PCB Control)
Climate solution for green environment
Nihao su
Flooded Type
Water cooled screw chiller
Technical service manual
LSBLG365~LSBLG1500/MCFN
MCAC-CTSM-2012-11
1

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Summary of Contents for Midea LSBLG365/MCFN

  • Page 1 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Flooded Type Water cooled screw chiller Technical service manual LSBLG365~LSBLG1500/MCFN Climate solution for green environment Nihao su...

  • Page 2: Table Of Contents

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Contents Product ......................... 3 Product Lineup ......................... 3 Nomenclature ........................... 3 Features ............................ 4 Operating Range ........................6 Specification ..........................7 Performance Data ........................9 System Schematic Diagram ....................14 Outline Dimension ......................... 14 Water Flow ..........................

  • Page 3: Product

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 I. Product 1. Product Line Up Series Cooling Model Picture Capacity (kW) LSBLG365/MCFN LSBLG465/MCFN Single head LSBLG560/MCFN LSBLG750/MCFN LSBLG825/MCFN LSBLG925/MCFN Dual head LSBLG1120/MCFN 1120 LSBLG1230/MCFN 1230 LSBLG1500/MCFN 1500 2. Nomenclature N: Factory mode F: Flooded evaporator C: R134a;...

  • Page 4: Features

    MCAC-CTSM-2012-11 3. Features Leading technology of twin screw compressor  Midea screw chiller is equipped with the 3rd generation industrial compressor that has the latest advanced 5-6 asymmetry dentiform Semi-hermetic Screw Rotors.  The rotors are processed by high-precision CNC and each part is well-proportioned and none-gap matched, which minimizes the friction resistance and clearance lost and also guarantees quiet running and good duration.
  • Page 5 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Efficient Lubrication cycle There are two oil separators which are separately  integrated inside the compressor and condenser. The refrigerant and oil mixture gets separated in the first oil separator inside the compressor and then to the second oil separator of which the separating efficiency can reach 99%.

  • Page 6: Operating Range

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 4. Operating Range Content Running range 5℃～15℃ Chilled Leaving Water Temperature 20℃~35℃ Cooling Entering water Temperature Water flow volume Rating flow volume±20% Max inlet/outlet water Temp. difference 8℃ Fouling factor (m ℃/kW) 0.086 Voltage tolerance...

  • Page 7: Specification

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 5. Specification Single head: LSBLG365 LSBLG465 LSBLG560 LSBLG750 Item Model /MCFN /MCFN /MCFN /MCFN Cooling Capacity 103．5 132.3 159.3 213.3 Refrigerant model R134a Refrigerant charged COP(Kw/kw) 5.87 5.96 5.89 6.15 Oil charge Liter HBR-B04/ 35 HBR-B04/ 39...
  • Page 8 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Dual head: Model LSBLG825 LSBLG925 LSBLG1120 LSBLG1230 LSBLG1500 /MCFN /MCFN /MCFN /MCFN /MCFN Item 1120 1230 1500 Cooling Capacity 234.6 262.7 318.5 349.7 426.5 Refrigerant model R134a Refrigerant charged COP(Kw/kw) 5.57 5.92 5.89 5.86...

  • Page 9: Performance Data

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 6. Performance Data Cooling water entering temp. ℃ Chilled water Model leaving Cooling Cooling Cooling temp.℃ Input(kW) capacity Input(kW) capacity Input(kW) capacity (kW) (kW) (kW) 341.1 60.0 333.1 61.6 326.1 64.3 352.4 61.1 347.3...
  • Page 10 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Cooling water entering temp. ℃ Chilled water Model leaving Cooling Cooling Cooling temp.℃ Input(kW) capacity Input(kW) capacity Input(kW) capacity (kW) (kW) (kW) 702.8 118.0 686.3 121.3 672.0 126.5 726.0 120.2 715.5 123.8 694.5 128.3...
  • Page 11 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Cooling water entering temp. ℃ Chilled water Model leaving Cooling Cooling Cooling temp.℃ Input(kW) capacity Input(kW) capacity Input(kW) capacity (kW) (kW) (kW) 1049.4 183.7 1024.8 188.9 1003.5 197.0 1084.2 187.2 1068.5 192.9 1037.1 199.9...

  • Page 12: System Schematic Diagram

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 7. System Schematic Diagram For single head unit (LSBLG365~750/MCFN) For dual head unit (LSBLG820~1500/MCFN)

  • Page 13: Outline Dimension

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 8. Outline Dimension Single head: Cooling Chilled Model water water Inlet/outlet Inlet/outlet 365/MCFN 3500 1400 1750 2850 1300 380 640 350 610 DN125 DN125 465/MCFN 3500 1400 1800 2850 1300 380 640 350 610 DN125 DN125...

  • Page 14: Water Flow

    The chiller control set points are based upon a constant flow and variable temperature. CHILLED WATER CONDENSER WATER Unit Model MIN. FLOW MAX. FLOW MIN. FLOW MAX. FLOW RATE RATE RATE RATE SIZE LSBLG365/MCFN LSBLG465/MCFN LSBLG560/MCFN LSBLG750/MCFN LSBLG825/MCFN LSBLG925/MCFN 1064 LSBLG1120/MCFN 1104 1293 LSBLG1230/MCFN 1213 1419...

  • Page 15: Installation

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 II. Installation Safety considerations Access to the unit must be reserved to authorized personnel, qualified and trained in monitoring and maintenance. The access limitation device must be installed by the customer. After the unit has been received, when it is ready to be installed or reinstalled, and before it is started up, it must be inspected for damage.

  • Page 16: Installation Foundation

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 copper pipes or exchanging pipes, there should be enough space reserved( for single compressor unit, it should be at least 3.5m, for dual compressor unit, it should be 5m), and the other end of the unit should have at least 2.0m space, use the hole on door or other holes with appropriate position;...
  • Page 17 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 the unit in balance. Install a shockproof foundation when necessary. 4) Vibration isolators are recommended for all roof mounted installations or wherever vibration transmission is a consideration. Neoprene Isolation is optional, it is recommended for normal installations and provides good performance in most applications for the least cost.

  • Page 18: Vibration Isolators

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 4. Vibration Isolators Put the absorbers under unit saddles before final positioned the unit. The quantity of absorber used for each unit is always decided by the elasticity or durometer value of the absorber. Below please refer to the typical isolation pad and vibration isolator for selection.

  • Page 19: Installation Of Water Pipeline System

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 5. Installation of Water Pipeline System Due to the variety of piping practices, it is advisable to follow the recommendations of local authorities. The installation and insulation of the water pipelines of the air conditioning system shall be designed and guided by design professionals, and confirm to the corresponding provisions of the HVAC installation specifications.
  • Page 20 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Pressure Drop (see product parameters) + Pipeline Resistance (length of the least favorable loop pipe * 0.05) + Local Resistance (length of the least favorable loop pipe * 0.05 * 0.5)) * (1.1 ~ 1.2) flow switch must be arranged on the drain pipe of the evaporator.
  • Page 21 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 10) In close loop water system, to diminish the impact on water pipe because of the expansion or contraction of water volume and to avoid the influence caused by supplementing water pressure, water return side should be fitted with an expansion water tank The expansion tank shall be installed 1~1.5m higher than the system, and its capacity accounts about 1/10 of the...
  • Page 22 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 moisture-proof seal. Any water piping to the unit must be protected to prevent freezing. There are reserved terminals for the auxiliary electrical heater. Logic in PCB will transmit ON/OFF signal by checking the leaving evaporator water temperature.

  • Page 23: Electrical Data

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 III. Electrical Data 1. Field Wiring In order to prevent any accident of injury and death during the site wiring , the power WARNING: supply shall be cut off before the line is connected to the unit. Wiring must comply with all applicable codes and ordinances.
  • Page 24 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 POW ER SUPPLY ELECTRICAL CONTROL [Diagram for External Wiring of LSBLG825~1500/MCFN Unit] Breaking isolation switches should be added between the power cord of users and the unit. The capacities of the breaking isolation switches recommended are as follows. BVR：Copper core PVC insulated soft wire Nominal Domestic...
  • Page 25 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Attention: refrigerant selection: the previous software settings are replaced by the current hardware settings to avoid the possibility of improper operation of the software leading to wrongly selected refrigerant and damage to the unit. In order to avoid wrong control in field connection, the liquid control circuit (24 V) shall not be in the same conduit with the lead wire with voltage higher than 24 V.

  • Page 26: Electric Parameter Table

    2. Electric parameter table Power Table Main power Power Range Rated Starting Max. Quantity Model current current running of comp. Highest/ Lowest/ current/A LSBLG365/MCFN LSBLG465/MCFN LSBLG560/MCFN 1340 LSBLG750/MCFN 1990 LSBLG825/MCFN 810*2 LSBLG925/MCFN 875*2 LSBLG1120/MCFN 1340*2 LSBLG1230/MCFN 1430*2 LSBLG1500/MCFN 1990*2...

  • Page 27: Control Flow Chart

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Control Flow Chart 2 Compressors Double-Head 380VAC 3P+N+PE Moulded Case Circuit Breaker Moulded Case Circuit Breaker Compressor Compressor Thermorelay Miniature Thermorelay Circuit Breaker Compressor Compressor Contactor Contactor Star-Delta Start Star-Delta Start 星三角启动...
  • Page 28 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Miniature Circuit Breaker: Protective condition: current passing the miniature circuit breaker exceeds its numerical protection value; Results of action execution: power-fail of corresponding circuit, failure of start, circuit breaker switch positioned in the OFF terminal Processing mode: inspect its rear end for burn-down of component(s) or short-circuit between circuits.

  • Page 29: Control Screen Structures

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 screen, failure of start. Processing mode: inspect whether the wiring of faulty sensor is proper and firm, and whether the sensor itself is normal. 4. Control Screen Structures Homepage Note: Please input the user password (58806)or user Mode Setting manage password(40828) to enter the white interfaces.

  • Page 30: Control Screen Operation

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 5. Control Screen Operation Initial Startup  Before power up for the first time，make sure that the wiring is firm between the control box and the main switch ， the insulation resistances reach the requirements ,and the earth wire has been properly installed.
  • Page 31 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Password Input Page  Mode Setting Page 【Mode Setting Page】 Control mode and working mode are to be set in this page: Control mode and running mode which have been selected currently for units are displayed here, and this position will correspondingly vary according to the choices of customers when selection of modes is changed.
  • Page 32 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 achieve the unit starting or stopping though the “Remote Start” and “Remote Stop” hardware interfaces; “TIMED” indicates the unit can achieve timing start/stop according to the time set by the user. ③...
  • Page 33 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 “NO.1” means only No.1 compressor is working. “NO.2” means only No.2 compressor is working. This position is the unit alarm display area, and alarm information of failure content will be displayed here in a mobile mode in case of any failure in units.
  • Page 34 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 system status indicates “shutting down” even the requirements of shutting down the compressor are not meet. The unit will execute shutdown action automatically after all of the requirements have been satisfied. ) The action of 4 functional keys in main page will be detailed in subsequent sections: ...
  • Page 35 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Note: ① “Max” in the upper left indicates the upper limit of the setting parameter; “Min” in the upper right indicates the lower limit. ② “Automatic On/Off”: Only displaying under Timed mode. Explanation: Setting Temp.
  • Page 36 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 non-existent date or time is not allowed, and we assume no liability or responsibility for setting of non-existent date or time and consequence resulting from this setting.  Screen Setting User can increase and reduce the brightness and contrast of screen by clicking on “+”and “-” in this page.
  • Page 37 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 on “ to switch to , set the time 0:00 in starting time and 16:00 in shutdown time on Thursday and click on “ to switch to ,all of the others time buttons are .
  • Page 38 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Current Data Display Input Click on “ ” to enter “Input Page” Input Status “ON” as displayed indicates the input point is closed; “OFF” as displayed indicates the input point is open.
  • Page 39 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Output “ON” as displayed indicates the output point is energized; “OFF” as displayed indicates the output point is de-energized. All of output points display “OFF” when the unit is in pause status. According to Start/Stop order, corresponding switch points start to execute action.
  • Page 40 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 relevant thermal relay in the control box to reset manually. History Alarm Information Click on button in Alarm Page to enter history alarm information query information, as shown in Picture 8.2. Max.5 warning messages can be recorded meanwhile. The messages will be updated automatically if there are more messages.
  • Page 41 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 1#排气温度传感器故障 1# Discharge temp. sensor failure 2#排气温度传感器故障 2# Discharge temp. sensor failure 冷冻水出水温度过低保护 Low chilled leaving water temperature Low cooling entering water temperature protection 冷却水进水温度过低保护 冷却水出水温度过高保护 High cooling entering water temperature protection 1#排气温度过高保护...

  • Page 42: Introduction Of Major Electric Components

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 6. Introduction of Major Electric Components Collect all digital quantities and analog quantities on units as well as inputs of quantities and touch screen PC Board commands, and realize different outputs by judgment of procedures to meet the requirement or normal and safe running of units.
  • Page 43 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Detect the quality of power supplied to units by the user, detect the voltage range of the power, the Power Protection imbalance rate of three-phase Module voltage, phase sequence and phase lack, and protect the units by inspecting the quality of power.

  • Page 44: Maintenance And Commissioning

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 IV. Maintenance and Commissioning Engineers working on the electric or refrigeration components must be authorized, trained and fully qualified to do so. All refrigerant circuit repairs must be carried out by a trained person, fully qualified to work on these units.
  • Page 45 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 e.g. at nominal voltage 3N~, AC380V, 50Hz, the measured UAB=376V, UAC=379V, UBC=385V. Average voltage = (376+379+385) 3= 380V Determined deviation from average voltage: △ UAB=380-376=4V, △ UAC=380-379=1V, △ UBC=385-380=5V, Maximum deviation: 5V 5/380=1.3%, the maximum phase voltage unbalance is 1.3%.
  • Page 46 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 [Communication Lines of PCB and Touch Screen] 1.2 Electrical Elements Parameters Settings Inspection Inspect whether the compressor overload protection value, which shall not exceed the maximum compressor permissible current value indicated in the nameplate on the compressor, is set correctly.
  • Page 47 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Inspect whether moisture content of the system exceeds the limit Excessive moisture content in the refrigerant system of the unit might cause ice block, copper plating, etc. that would seriously affect the safety of the unit. Therefore, the dryness of the refrigerant system of the unit shall be inspected from the sight glass before and during operation of the unit, purple indicating dry, and pink moist, as shown in the right figure.
  • Page 48 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 connection bolts of upper/lower terminals of AC contactor, etc.) are firmly fixed. Inspect the connections in the electrical cabinet for looseness, especially the electric part in the cabinet. The parts connected by bolts might be loose due to transportation. If there is any looseness, tighten it to avoid burnout of circuit or element caused by poor contact.
  • Page 49 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 convenience of heat transfer. Thermostatic insulation and enclosing measures shall be taken for the temperature sensing device. Inspect whether there is temperature deviation for the entering and leaving water temperature sensor caused by insufficient heat transfer oil in the thermostatic pipe. For later armored dip-type temperature sensor, no lubricating oil is required for heat transfer.
  • Page 50 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 0.39 0.47 0.57 0.67 0.79 0.92 If the high/low voltage deviates much from the saturation pressure corresponding to the current temperature (more than 2bar), leakage or insufficient refrigerant is likely in the system. (2) Inspect the unit for normal heating Before start-up, it is necessary to inspect whether the oil heating in the unit is available, and whether the oil heater does not work when there is oil for heating but no power supply.

  • Page 51: Maintenance And Service

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 (6) Inspect whether the flow in the water pump meets the requirements of the unit. (7) Inspect whether the power supply of the unit is stable. Parameters Inspections during Start-up and Operation (1) The maximum range of parameters for normal operation of R134a refrigerant unit See table 2 for the maximum range of performance parameters of R134a refrigerant: [Table 2]...
  • Page 52 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 8) Do not climb on a machine. Use a platform, or staging to work at higher levels.Use mechanical lifting equipment (crane, hoist, winch, etc.) to lift or move heavy components. For lighter components, use lifting equipment when there is a risk of slipping or losing your balance.Use only original replacement parts for any repair or component replacement.
  • Page 53 2.2 Protection items and Troubleshooting Midea screw chiller has many protection measures and devices. There’re many features to aid in troubleshooting. By using the alarm information, DI/O, AI/O and operating conditions of the chiller during chiller operation, it’s convenient to find the possible problem. Verify that the chiller is properly configured, including options and/or accessories.
  • Page 54 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 fault occurs during chiller operating, the chiller will stop according to protective stop program. Both compressors are shut down and water pumps and cooling tower fan stops in accordance with normal shutdown procedure. When fault record gets cleared and both temperature and time condition gets satisfied, the chiller can restart.
  • Page 55 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11  High/low pressure protection Alarm as soon as high pressure switch trips and stop the chiller immediately according to abnormal shutdown program. It is one kind of NC switch and needs manual reset of the red reset button when fault happens.
  • Page 56 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 gets satisfied, the chiller can restart. Comp. OFF 42°C 38°C Comp. ON  Over current protection of compressor The protection trips when compressor current > set point. Faulted compressor will stop immediately to abnormal protective shutdown program and other normal system will keep on running.
  • Page 57 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Troubleshooting: Alarm Trouble Description Action Reset Type Possible Cause Compressor can not work; The The power quality is poor, there may exist Phase sequence relay Power Failure Protection compressor stop running Reset manually on the touch screen phase inversion, lacking phase or phase switches OFF...
  • Page 58 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 1,The cooling water quality is too bad and the heat exchange of condenser is abnormal 2,There is too much non-condensable gas in the system The compressor which exists High pressure switch Press red reset button,reset 3,The cooling water flow too small or the High-pressure Protection...
  • Page 59 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 1,The superheat too high( the refrigerant not enough, EXV failure) 2,The discharge pressure too high The compressor The protection is relieved once the The compressor which exists 3,The oil level too low and the oil volume in High Discharge Temperature discharge temperature discharge temperature is lower than...
  • Page 60 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 EXV Troubleshooting: Problem Reason Solution Measured Measured superheat Check that the measured pressure and temperature superheat value is incorrect sensors correctly and the correct position. value is Check on the drive set minimum and maximum Set the wrong type of incorrect pressure pressure sensor parameter with the range...
  • Page 61 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 degree superheat can be closed: the proportion coefficient increases to temperature is not low, but 30, integral time increased to 250 seconds, there is still liquid flows differential time increased to 10 seconds back to the compressor unit A plurality of refrigerator...
  • Page 62 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 compressor closed the drive is not in standalone mode equipment) Configured Check the digital input terminal. Check that when the stand-alone mode, control signal input correctly when closed. Check drive does not begin to that the drive is in stand-alone mode control the valve remains closed...
  • Page 63 Failed tubes should be replaced as soon as possible. Up to 10% of the total number of tubes can be plugged before retubing is necessary. If the problem is much more serious, contact your local Midea or your local representative for assistance.
  • Page 64 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Torque rang (N.m) Bolt specifications Max. Min. Fig.:6.2.1 Fig. 6.2.2 1. Install all bolts finger tight. 2. Bolt tightening sequence is outlined in Fig. 6.2.2. Follow the numbering or lettering sequence so that pressure is evenly applied to O-ring.
  • Page 65 Warning: When doing cleaning with unit stops, volume of cooling tower flume can be 1/2 or 1/3 of rated value; but if doing cleaning with unit is runs, the volume of cooling tower flume should keep rated value. Midea assumes no responsibility for pressure vessel damage resulting from untreated or improperly treated water.
  • Page 66 It should be recognized that atmospheric air contains many contaminants that increase the need for proper water treatment. The use of untreated water can result in corrosion, erosion, sliming, scaling or algae formation. Midea assumes no responsibility for the results of untreated or improperly treated water.
  • Page 67 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 e) The evaporator refrigerant level slightly laps last tubes row by checking the sight glass installed on each evaporator for a visual inspection. f) The condenser refrigerant level to be included between the condensing and the sub-cooling sections by checking the sight glass installed on each condenser for a visual inspection.
  • Page 68 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Discharge the residual refrigerant in the gas system. Carry on replacement of the parts of the system. After the replacement, extract vacuum in the gas part. After the vacuum extraction, keep the negative voltage until the resumed vacuum in the unit meets the requirements.
  • Page 69 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 correct operation of the corresponding circuit. Oil Charging/Low Oil Recharging  Pre-cautions in changing of oil 1. Use only qualified oil and do not mix different brand of oil together. Different kinds of refrigerant should match different kinds of oil, note that some synthetic oil is incompatible with mineral oil.
  • Page 70 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 changed (if necessary) after the initial 2000 hours of compressor operation. Oil line pressure loss is monitored by the control and reported for each compressor as the oil filter pressure drop. Normally the pressure differential (discharge pressure minus oil pressure) is typically less than 150kPa for a system with clean internal and external filters.
  • Page 71 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 accessories. 8) Remove the M14 bolts securing the discharge line flange located between compressor and oil separator. In the same way, remove the bolts securing the suction line flange between evaporator and compressor if there is no suction service valve.
  • Page 72 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Change filter drier at the first sign of moisture in the system. IMPORTANT: Unit must in operation for at least 12 hours before moisture indicator can give an accurate reading. With the unit running, the indicating element must be in contact with liquid refrigerant to give true reading.
  • Page 73 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 The units are equipped with compressor protection modules built in the wiring cabinet of compressor. INT69 HBY and JTX-A module is designed to detect the motor winding temperature, phase sequence and phase loss. The detecting signal of JTX-A is voltage type. When motor winding temperature reaches set point, the module will cut off control circuit immediately.
  • Page 74 • Yellow led Replacing Defective PCB Controller For Midea screw chiller, it adopts special refrigeration PCB controller. The program and data is written into the memory by Midea in the replacement module. When ordering any replacement module, specify the model of unit and information of user (Name/Country/Installation time of unit). Return the faulted module to Midea.
  • Page 75 6. Remove condenser heads at least once a year to inspect the condenser tubes and clean if required. Recommended maintenance schedule This chapter shows the preventive maintenance of Midea screw chiller. Correct maintenance and timely service will make the chiller in the best condition and with best performance, beside, it can prolong the lifespan of chiller.
  • Page 76 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 with local customer service centre of Midea after chiller out of warranty, to keep the chiller always under effective service and guarantee reliable operation. Note: Repair work caused by incorrect maintenance within warranty will lead to extra charges.
  • Page 77 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 cleanness work is in urgent need. When the chiller stops for a long time, water in heat exchangers and pipe system should be drained thoroughly. For newly installed chiller, the filters in water system should be cleaned after running for 24 hours and then clean the filters quarterly.
  • Page 78 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 connect the protection switches to the system before starting up the unit for long-time running. Open the water pump and wait until the water flow is stable before starting up the master compressor.

  • Page 79: Control

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 V. Control 1. Description of Energy Adjustment Energy adjustment may be controlled by either entering water temperature or leaving water temperature in case of operation of single-module unit, and it can only be controlled by entering water temperature in case of multi-module interconnection.
  • Page 80 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 For easier startup of compressor, the loading must be minimized. Therefore, SV1 is energized to bypass oil to the low-pressure side directly. The slider does not move and keep the maximum opening in suction end to bypass the refrigerant.

  • Page 81: Description Of Cooling Tower Fan Control

    2. Description of cooling tower fan control For Midea screw chiller, it adopts professional PCB controller to maintain the saturated condensing temperature to a configurable set point. Cooling tower fan is controlled by cooling leaving water temperature.
  • Page 82  Cooler and Condenser Pump Control Midea chillers can be configured for cooler and condenser pump control. Inputs for a cooler pump interlock and condenser flow switch or interlock are provided. Refer to appendix for details. Cooler pump control Proper configuration of the cooler pump control is required to prevent possible cooler freeze-up.

  • Page 83: Demand Limit

    Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 outlet of both the Condenser and Evaporator and the length A of water flow switch should be 5 times the length of the pipe diameter. Adjust the target of water flow switch according to the water pipe specification (Refer to the manufacturing manual).
  • Page 84 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11  General wiring diagram Explanation Terminal G\G0 Power supply VABT Emergency Power Supply Functional ground 1,2,3,4 Stepper motor power supply COM1,NO1 Alarm Relay Signal Ground VREF Sensor power supply Sensor 1 (pressure) or an external signal 4 to 20mA Sensor 2 (temperature) or 0 to 10V external signal...
  • Page 85 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Appendix 1: R134a saturation temperature - pressure corresponding tables R134a saturation temperature - pressure corresponding tables ℃ ℃ ℃ ℃ 1351 1385 1420 1455 1492 1528 1566 1604 1642 1682 1722 1017 1763 1044...
  • Page 86 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Appendix 2: Requirement for cleaning and maintenance Water quality Scale Corrosion Remark Generates insoluble PH≤6 Acid water Hard Strong CaSO Soft fluid deposit may be PH≥8 Alkali water Soft —— caused by ions iron or aluminum Water with much Ca Easily generates hard...
  • Page 87 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Appendix 3: Electrical Wiring Diagram LSBLG365-750/MCFN X:13 X:14 X:42 X:45 X:47 1SP2 1SP1 X:12 X:15 X:41 X:43 X:44 X:46 X:48 206 208 X:27 X:31 X:33 X:35 X:5 1SV5 1YV3 1YV2 1YV1 X:28 X:32 X:34 3/E2...
  • Page 88 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 ～ 220V X:50 X:55 X:58 X:67 X:17 X:18 X:51 X:54 SQ1 SQ2 +V -V X:16 X:19 X:49 X:52 X:53 X:56 X:57 X:68 230 232 404 406 X:8 X:9 X:10 2/F11 2/F11 RS485 Communication 1/F11 Note:...
  • Page 89 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 2/F12 2/F12 613 615 605 603 601 607 X:61 X:60 X:59 X:62...
  • Page 90 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 LSBLG825-1500/MCFN L1 L2 L3 12 11 14 1/G2 1/G4 2/B2 1TA1 1TA2 2TA1 2TA2 3/B9 3/B9 1KM1 2KM1 ～ X:29 24V 0V X:32 220V 1KM1 2KM1 1KM2 2KM2 +V -V RS485 Communication 4/F2 X:30 X:31...
  • Page 91 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 1/C11 3/F2 4/A5 1KM3 2KM3 1KM2 2KM2 1KM3 1KM1 2KM3 2KM1 1KM2 2KM2 1KM1 1KM2 1KM3 2KM1 2KM2 2KM3 1/E11 3/F2 4/A5...
  • Page 92 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 X:65 X:18 X:19 X:56 X:59 X:62 2KM1 1KM1 1SP2 1SP1 2SP2 2SP1 X:64 X:17 X:20 X:55 X:57 X:58 X:60 X:61 X:63 X:66 2KM2 1KM2 208 210 224 226 228 230 309 311 313 323 325 327 329 X:35 X:37...
  • Page 93 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 ～ X:67 220V X:22 X:23 X:78 X:70 X:71 X:74 X:75 X:79 X:82 X:83 SQ1 SQ2 +V -V X:21 X:24 X:68 X:69 X:72 X:73 X:76 X:77 X:80 X:81 X:84 240 242 402 404 406 410 404 331 333 X:12 X:13...
  • Page 94 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 2/B12 2/E12 613 615 631 633 2EVD 1EVD 605 603 601 607 623 621 619 625 X:87 X:86 X:85 X:88 X:95 X:94 X:93 X:96 2BP P...
  • Page 95 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 Appendix 4: Explosive View (Take LSBLG465/MCFN for example) Unit Name：Flooded Type Water-cooled screw chiller Unit Model：LSBLG465/MCFN...
  • Page 96 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11 中文 Part Name Quantity BOM code Condenser 201790207873 冷凝器 Left shell cover 左水室 Left shell sealed shim 左水室垫片 Angle valve 201600801155 直角截止阀(DN8) Safty valve 201604100115 安全阀 Right shell sealed shim 右水室垫片 Right shell cover 右水室...
  • Page 97 Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11...

This manual is also suitable for:

Lsblg465/mcfnLsblg560/mcfnLsblg750/mcfnLsblg825/mcfnLsblg925/mcfnLsblg1120/mcfn ... Show all

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