Midea LSBLG320/MZ Technical & Service Manual
  1. Manuals
  2. Brands
  3. Midea Manuals
  4. Chiller
  5. LSBLG320/MZ
  6. Technical & service manual

Midea LSBLG320/MZ Technical & Service Manual

Water-cooled screw chiller lsblgxxx/mz series
Hide thumbs
Table of Contents

Advertisement

Quick Links

Technical Service Manual
Water-cooled
Screw Chiller
Model:
LSBLG***/MZ

Advertisement

Table of Contents
loading

Related Manuals for Midea LSBLG320/MZ

Summary of Contents for Midea LSBLG320/MZ

  • Page 1 Technical Service Manual Water-cooled Screw Chiller Model: LSBLG***/MZ...

  • Page 2: Table Of Contents

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Contents Ⅰ. Safety precautions ....................... 2 Installation safety considerations ....................2 2. Maintenance safety considerations ..................... 3 3. Repair safety considerations ........................ 4 Ⅱ. Product .......................... 6 1.General information ..........................6 Features ..............................8 3.

  • Page 3: Ⅰ. Safety Precautions

    (e.g. following a shock). If in doubt, carry out a leak tightness check and verify with the manufacturer that the circuit integrity has not been impaired. If damage is detected upon receipt, immediately file a claim with the shipping company. Midea strongly recommends employing a specialized company to unload the machine.

  • Page 4: Maintenance Safety Considerations

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) oxygen and cause asphyxiation or explosions. Inhalation of high concentrations of vapour is harmful and may cause heart irregularities, unconsciousness, or death. Vapour is heavier than air and reduces the amount of oxygen available for breathing. These products cause eye and skin irritation. Decomposition products are hazardous.

  • Page 5: Repair Safety Considerations

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03  Ensure regularly that the vibration levels remain acceptable and close to those at the initial unit start-up. Before opening a refrigerant circuit, purge and consult the pressure gauges.  Change the refrigerant when there are equipment failures, following related regulations or carry out a refrigerant analysis in a specialist laboratory.
  • Page 6 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)  Do not siphon refrigerant. Avoid spilling liquid refrigerant on skin or splashing it into the eyes. Use safety goggles. Wash any spills from the skin with soap and water. If liquid refrigerant enters the eyes, immediately and abundantly flush the eyes with water and consult a doctor.

  • Page 7: Ⅱ. Product

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Ⅱ. Product 1.General information 1) .Product Lineup Power Cooling Series Model Compressor Capacity (kW) supply LSBLG255/MZ 380V/3N/50Hz LSBLG320/MZ 380V/3N/50Hz Single head LSBLG400/MZ 380V/3N/50Hz LSBLG485/MZ 380V/3N/50Hz LSBLG630/MZ 380V/3N/50Hz LSBLG860/MZ 380V/3N/50Hz LSBLG970/MZ 380V/3N/50Hz LSBLG1060/MZ...
  • Page 8 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 3). External Appearance LSBLG255/MZ~ LSBLG860/MZ LSBLG970/MZ~ LSBLG1490/MZ...

  • Page 9: Features

    MCAC-CTSM-2014-03 2. 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...
  • Page 10 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)  The installation and adjustment are simple .Standard flange connection and wire mesh to the electrical panel. Refrigerant and lubrication oil are provided to the unit in the factory. Only piping connection and power supply connection are required on the site. Wide application range ...

  • Page 11: Specifications

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 3. Specifications Single head LSBLGXXX/MZ Cooling capacity Power input 53.6 kW/kW 4.73 4.75 4.71 4.85 5.02 4.97 Semi-hermetic screw compressor Circuit A Quantity Circuit B Quantity 25%,50%,75%,100% four steps control Capacity Control (25%,50%-100% Stepless as Option) Oil recharge Type...
  • Page 12 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Dual heads LSBLGXXX/MZ 1060 1260 1490 Cooling capacity 1057 1256 1487 Power input kW/kW 4.85 4.94 5.02 4.99 Semi-hermetic screw compressor Circuit A Quantity Circuit B Quantity 25%,50%,75%,100% four step control Capacity Control (25%,50%-100% Stepless as Option) Oil recharge Type...

  • Page 13: Outline Dimension

    Cooling Water Outlet Chilled Water Outlet Cooling Water Inlet Cooling Chilled Model Water Water In/outlet In/outlet LSBLG255/MZ 2800 1165 1350 1600 1780 DN80 DN80 LSBLG320/MZ 2800 1165 1350 1600 1760 DN80 DN80 LSBLG400/MZ 2860 1285 1420 1600 1000 1780 DN100 DN100 LSBLG485/MZ...

  • Page 14: Refrigeration System

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 5.Refrigeration system For single head unit (LSBLG255~630/MZ)
  • Page 15 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 For single head unit (LSBLG860/MZ)
  • Page 16 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) For dual heads unit (LSBLG970~1260/MZ)
  • Page 17 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 For dual heads unit (LSBLG1490/MZ)

  • Page 18: Major System Components

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 6. Major System Components Major components of the unit (1)Single compressor parataxis type unit Name Controller Pressure Gauge Compressor Evaporator Safety Valve Condenser Expansion Valve Emergency Stop...
  • Page 19 6.1 Compressor Advanced twin screw compressor  Midea screw chiller equipped with the 3 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 matching, which minimizes the friction resistance and clearance lost, guarantees quiet running and good duration.
  • Page 20 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)  With 5-6 asymmetry dentiform, the screw rotor gained patent by improving the shape of German rotor GHH, proved having good balance, small vibration, and low noise due to balance testing by special machine.
  • Page 21 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03  Lubricant: The lubricant is supplied automatically by pressure difference inside the compressor. It is unnecessary to add an extra lubricant pump.  The Oil Separator comes from MANN of Germany and has reliable qualification. The oil content can be controlled below 3ppm (the oil content treated by oil-gas separator of common like screw-type air compressor is no less than 8-10ppm).

  • Page 22: Water Flow

    6.2.6 Evaporator Midea Screw Chiller is equipped with high efficiency shell and tube evaporator that are constructed by seamless steel tube with anti-corrosive treatment. The evaporator is a direct expansion type with refrigerant inside the copper tubes and water on the outside. The copper tubes are roll expanded into carbon steel tube plates.
  • Page 23 Model Chilled water Chilled water Chilled water Cooling water Cooling water Cooling water minimum rated maximum minimum rated maximum LSBLG255/MZ LSBLG320/MZ LSBLG400/MZ LSBLG485/MZ LSBLG630/MZ LSBLG860/MZ LSBLG970/MZ LSBLG1060/MZ LSBLG1260/MZ LSBLG1490/MZ Pressure drop DX type (Evaporator) Water flow (m3/h) LSBLG255/MZ LSBLG320/MZ LSBLG400/MZ...
  • Page 24 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Water flow (m3/h) LSBLG970/MZ LSBLG1060/MZ LSBLG1260/MZ LSBLG1490/MZ DX type (Condenser) Water flow (m3/h) LSBLG255/MZ LSBLG320/MZ LSBLG400/MZ LSBLG485/MZ LSBLG630/MZ LSBLG860/MZ...
  • Page 25 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Water flow (m3/h) LSBLG970/MZ LSBLG1060/MZ LSBLG1260/MZ LSBLG1490/MZ System minimum water volume: It is often necessary to add a buffer water tank to the circuit in order to achieve the required water volume. The tank itself must be internally baffled in order to ensure proper mixing of the liquid (water or brine).

  • Page 26: Unit Sound Levels

    10. Recommend breaker current All units has equipped with breaker with user. All refrigerant circuit repairs must be carried out by a trained, qualified and skilled technician and following local regulations Midea recommended breaker current for units as follow: Model Rated current (A)

  • Page 27: Operating Range

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 same time, so the starting current of 970-1490 models are the single compressor start-up current value. Note: (1) Values obtained at standard unit operating conditions: evaporator entering/leaving water temperature = 12° C/7° C. Condenser entering/leaving water temperature = 30° C/35° C. (2) For the dual compressor unit, we suggest equipped with breaker for each circuit.
  • Page 28 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) For low-temperature applications, where the leaving water temperature is below 5° C, freeze protection switch will work unit stop. If the temperature leaving the condenser is below 19° C,the unit will stop and warning. Ambient temperatures: During storage and transport of the LSBLG***/M units.

  • Page 29: Capacity Table

    391.50 65.85 381.63 68.17 15.00 446.92 60.74 437.43 62.85 432.67 63.87 422.84 66.10 417.77 67.24 407.31 69.66 LSBLG320/MZ Cooling Water Inlet Temp.(° C) Chilled Water 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Outlet Temp. Capacity Power Capacity Power Capacity...
  • Page 30 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) LSBLG400/MZ Cooling Water Inlet Temp.(° C) Chilled Water 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 31 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 LSBLG630/MZ Cooling Water Inlet Temp.(° C) Chilled Water 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 32 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) LSBLG970/MZ Cooling Water Inlet Temp.(° C) Chilled Water 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 33 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 LSBLG1260/MZ Cooling Water Inlet Temp.(° C) Chilled Water 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...

  • Page 34: Accessories

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 13. Accessories Standard accessories Name Quantity User manual Water flow switch Packing list Optional Accessories Name Model Instructions Picture Quantity Installed on evaporator Water flow WFS-1001-H outlet pipe to prevent switch (Honeywell) heat exchange pipe from frost crack.

  • Page 35: Ⅲ. Control

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Ⅲ. Control 1. Control Flow Chart 2 Compressors 380VAC Double-Head 3P+N+PE Compressor Compressor Miniature Thermorelay Thermorelay Circuit Breaker Compressor Compressor Contactor Contactor Star-Delta Start Star-Delta Start Main base controller Terminal for Terminal for External Signal Output Action e.g.

  • Page 36: Energy Adjustment

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 2. Energy Adjustment The unit adjust capacity by chilled water. The control logic refers to the picture. Energy adjustment is districted when starting high pressure is too high. High pressure unloading 19Bar 18Bar Normal adjusting...

  • Page 37: Start/Stop Process

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 3. Start/stop process 1).Cooling start Power-on Detect fault Clear failure Start on pump on Water flow Stop.Clear failure switch protection Water temp is ok. Stand by Oil heating time is enough Stop time is enough Compressor 25% SV on Compressor Y-△...

  • Page 38: Sensors

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 2) Cooling stop stop Running time Stand by is enough Unload to 50% step Unload to 25% step Compressor off Compressor 25%SV off Cooling tower off Cooing pump off Chilled pump off 4.
  • Page 39 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03  Thermistor replacement To Replace Thermistors RT1, RT2, RT3, RT4, RT5, or RT6 (Entering/Leaving chilled Water; Entering/Leaving cooling Water; Discharge Temperature; Oil temperature) — Disconnect appropriate connector from the PCB controller. New thermistors should be spliced to existing wiring close to the connector unless new connectors are required.

  • Page 40: Parts Control

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 5. Parts control 1). Oil heater control In unit sand by period, oil heater is energized to keep normal oil temperature. When unit starts, it is turned off. Oil heating time limits: ...
  • Page 41 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 24V AC Alarm output to controller CAREL EXV controller EVD Suction pressure Start/stop relay transmitter From controller Suction temp. thermistor EXV controller is started by main base controller.it detects suction pressure and suction temperature and calculate suction superheat.
  • Page 42 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Remove cover Change display Display Display suction superheat Display EXV opening Relay output status Alarm Start of the protection Control state Buttons Function Open the display screen, enter the password to enter the programming mode •...
  • Page 43 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 • From the parameter setting mode, the display switches to • Confirm the list of parameters and return the value Enter Running status display Display all status Press Press button c. Controller parameter checking and changing. Checking or changing repair parameters step: ①...
  • Page 44 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) ⑨ Repeat the above 5, 6, 7, 8 step change other parameters; ⑩ Press Esc to exit the repair parameters modify the program. The following shows the detailed settings: 9 pages Drive hardware configuration Drive hardware configuration Refrigerant type Network address...
  • Page 45 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 - the special parameters - alert configuration parameters - valve parameters ⑤ Press UP/DOWN button to select the category, and then press ENTER to enter the first class number ⑥ Press UP/DOWN to select parameters to be set, and then press ENTER to move to the parameter value;...
  • Page 46 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Pressure sensor S1: minimum value Set based on the actual sensor Pressure sensor S1: maximum value Set based on the actual sensor Pressure sensor S1: minimum value for alarms Set based on the actual sensor Pressure sensor S1: maximum value for alarms Set based on the actual sensor...

  • Page 47: Operation Part

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 6. Operation Part 6.1 Unit operation flow chart Welcome page Note: use the user password (58806) or administrator password (40828) to enter the white window Main page Use the administrator password (40828) to enter the purple window.
  • Page 48 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Delete Clear Main control board and HMI program version number Figure 6.1 When press Enter button, password keyboard will appear. User input 58806/40828 and press Enter button to enter the main page. Indicators explanation on the right are as following: Yellow indicator is the power indicator.
  • Page 49 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Press LOCK button at the bottom right of the screen, and machine enters the initial screen, user needs to input password again to enter. Refers to the below table for the current status displaying and explanation of the unit:: Standby Machine is not operating, it can start normally.
  • Page 50 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Figure 6.3 Set control mode(Local, remote, timer),operating mode(cooling, heating, pumping) and single or dual compressor(dual stage, 1#、2#) in the pop-up window. After setting is finished, click the pop-up window "X" at the top right to close the pop-up window. ①Only control mode can be switched during operating, other mode selection is invalid.
  • Page 51 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Figure 6.4 If the startup conditions are not satisfied, press "Start" button will display the prompt at the top of the pop-up boot window, it shows that "compressor start conditions are not met, please check status information".
  • Page 52 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Figure 6.5 Startup operation: Press “startup” is not valid if unit is in malfunction state. Press START button, and confirm in the pop-up window for startup, then unit can start. If the compressor startup conditions are not satisfied, the unit goes into a pause state after running the water pump.
  • Page 53 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Press status in the figure 6.5 and enter figure 6.6. Displaying of unit without oil temperature sensor displaying of unit with oil temperature sensor Figure 6.6 Displaying contents of status information including the following: ①...
  • Page 54 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) ⑥ Display if unit gives an alarm, and which unit head gives the alarm exactly; ⑦ Display if the compressor oil heating is finished. If compressor starts, It need to be satisfied that oil heating time is ‘０’or oil temperature is satisfy with compressor start”...
  • Page 55 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 3.1 Status information- display of temperature and pressure Figure 6.7 3.2 Status information-input status: Input status page: “ON” represents the input point is closed, OFF represents the input point break. “Compressor overload protection switch”, when the machine is overload, “compressor overload protection switch”...
  • Page 56 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) contactor has action. 3.3 Status information-output status Output status page: ON represents the output point is powered on, OFF represents the input point is powered off. When the unit is in a shutdown state, all state display is OFF. According to the startup / shutdown command, the relative switch action is activated.
  • Page 57 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Dialog box like figure 6.11 appears if user inputs wrong password. Press Confirm button and go back to the input interface, then input password again. Figure 6.11 5. User parameter setting-temperature setting Input the password （40828）and enter the page as figure 6.12 as below: Manual input is...
  • Page 58 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) factory setting is 2℃,if temperature is within ± 0.5℃ of control temperature, the unit does not execute the loading/unloading action; ③ The target value of temperature control: it represents the target value of water temperature control;...
  • Page 59 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Press adjust Figure 6.14 5.3 User parameter setting- Automatic On/Off If user wants to use timer function of start or shutdown, it needs to choose “timer” in control mode of the figure 2 and enters user setting. Press AUTOMATIC ON/OFF and enter figure 6.15 as below: Manual input is possible...
  • Page 60 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 6. Alarm window Press Alarm button in the main page and enter real-time alarm window, as figure 6.16 below. Figure 6.16 If the alarm happens, unit executes orders according to the fault program. After fault recovery, press the “reset”...
  • Page 61 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Figure 6.17 Please refers to the actual operation interface; it is subject to change without notice.

  • Page 62: Safety Protection

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 7. Safety protection Name Code Brand Setting Range Location ON 0.30Mpa Low-pressure YK-0.3/0.20- JUNLE OFF 0.20Mpa Switch O-R-7000 ON 1.9Mpa High-pressure YK-1.9/1.4-C- JUNLE OFF 1.4Mpa Switch 1 R-7000 Note: Manual reset is needed for high-pressure switch. Safety Devices ...
  • Page 63 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03  High/low pressure switch All compressors have factory-installed high/low-pressure switches. See Table.6.10 Table – High/low-pressure switch settings High-pressure switch setting Low pressure switch setting UNIT Protection value Reset Value Protection value Reset Value LSBLG***/MZ 19bar 14bar...

  • Page 64: Ⅳ.electrical Control

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Ⅳ.Electrical control 1.Electrical data LSBLGXXX/MZ 1060 1260 1490 Standard voltage 380V 3Ph 50Hz Voltage range 340~420 Max. running current Max. power 127. 148. 188. 255. 296. 329. 376. 443. 80.6 95.5 consumption Rated current Compressor A Locked rotor Amps.
  • Page 65 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 2) Time Relay and Intermediate Relay The time relay is an automatic switch device which performs delayed control based the electromagnetic or mechanical principles. It controls the star delta switching time for the compressor contactor.

  • Page 66: Electrical Parts Parameter Setting

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 6). Solenoid Valve When the solenoid valve is energized, the electromagnetic coil generates electromagnetic force to pull up the closed component from the valve seat and the valve is open. When the solenoid valve is powered off, the spring pushes the closed component to the valve seat once the electromagnetic force disappears and the valve is closed.
  • Page 67 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 2) Schneider Power protector setting Power protector use schneider RM17TU type. ① Select the voltage class. For standard units, the voltage are 380 V. ② Set the delay time to 6s. ③ Set the under voltage value to 10%. Note: Set the processing parameters only when the system is powered off.
  • Page 68 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Note：Compressor overload relay, only apply to 3UA series of Siemens brand 5).Compressor thermal relay value: The calculation of compressor overload value (transformation ratio of current mutual inductor is A/B) is as follows: (Maximum running current of compressor/current mutual inductor A) x B = Thermal relay value of compressor.

  • Page 69: Field Wiring

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 4.Field wiring 1) Wiring diagram [Wiring Diagram of 255；320；400；485; 630; 860] POWER SUPPLY ELECTRICAL CONTROL [Wiring Diagram of 970；1060；1200；1260; 1490] 2)Recommended cable and mould case circuit breaker...
  • Page 70 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Electric Cable (mm Capacity of Type Breaker Phase line PE line Note: It is recommended that only copper-conductor cables are used in this unit. In high-altitude areas with high temperature, temperature derating should be considered, that is, the capacity of breaker device should...
  • Page 71 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Chilled water pump wiring for 970；1060；1200；1260; 1490 models control cabinet wiring terminal contactor Intermediate relay Pump motor Cooling water pump wiring for 255；320；400；485; 630; 860 models control cabinet wiring terminal contactor Intermediate relay Pump motor...
  • Page 72 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Cooling water pump wiring for 970；1060；1200；1260; 1490 models control cabinet wiring terminal contactor Intermediate relay Pump motor 4) Cooling and chilled water flow switch wiring Typically, a water flow switch is installed in the pipe of cooling water system to monitor the flow status of cooling water in real time.
  • Page 73 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Chilled water pump wiring Diagram of 255；320；400；485; 630; 860 models Chilled water pump wiring Diagram of 970；1060；1200；1260; 1490 models 5) Remote control wiring The wiring ports for remote start/stop, flow switch, water pump linked control, alarm indication, etc. are reserved in the electrical cabinet of the unit, with the numbers shown in the diagram below.

  • Page 74: Ⅴ. Installation

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Ⅴ. 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 75 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Dual compressors parataxis type unit Any person is not allowed to stand below the unit when sling it. 2).Foundation ① Please take into account the construction of installation foundation. Attention should be especially paid to the intensity of the floor and noise elimination when installing the unit in interlayer or on the top floor.
  • Page 76 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Refer to the following charts for the installation basement and fixation of unit. The sizes of foundation bolts of different models are shown below: LSBLG***/MZ Model 1060 1260 1490 D(mm) 1600 1600 1600 1600 1800...

  • Page 77: Water Pipeline System Installation

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 3).spaces 1) Leave enough space above and around unit for operation and maintenance. For cleaning the 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 78 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) analyzed before being used, such as PH value, conductivity, concentration of chloride ion, concentration of sulfide ion, and so on. ※ Applicable standard of water quality for the unit Total Conductivit Sulfid Chlorid Ammoni Sulfate...
  • Page 79 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Propylene Glycol Evaporator side Cooling Quality of Freezing Power Water flow Water capacity glycol （%） point ℃ modification modification resistance modification 0.968 0.969 1.01 1.16 0.964 0.955 1.028 1.287 0.955 0.937 1.05 0.945 0.914 1.078...
  • Page 80 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) G= cooling capacity×2.6L Process type cooling G= cooling capacity×7.4L b. In certain occasion (especially in manufacture cooling process), for conforming the system water content requirement, it’s necessary to mount a tank equipping with a cut-off baffle at the system to avoid water short-circuit, Please see the following schemes: Error Error...
  • Page 81 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 e Thermometer f Platinum resistance thermometer g Air vent h Water pump I Drain valve j Y- shape strainer Note: All of water pipe accessories and flow switch is provide by user. Chilled water piping suggested piping as follow：...
  • Page 82 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) interlocked with the input contact in the control cabinet. Its installation requirements are as follows: (1) The flow switch shall be installed on the pipe vertically. (2) The straight pipe section at each side of the flow switch shall have a length that is at least 5 times the pipe diameter;...
  • Page 83 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 11) The drain connection is arranged on the evaporator cylinder. The drain outlet has been equipped with a 1/2’’ plug. 12) In order to expel the air from water system, install an automatic discharge valve on the highest place of local water pipe and the horizontal pipe should be up tilted for about 1/250 degree.

  • Page 84: Wiring Installation

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) manual type, open the discharge valve of the chilled water pipeline to discharge all air in the pipeline. 23) Adjust the flow and inspect whether the water pressure drop of the evaporator meets the requirement of the unit’s normal operation.
  • Page 85 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 connection of the temperature sensor. Common two-core cable (2×0.75mm2) shall be used for the connection of flow switch to connect to the NO contact of the switch, i.e. the opening point when waterless. Two buttons can be connected to the external of remote start and stop. If the customer desires the linked control of the water pump, connect the water pump as shown in the diagram, where an intermediate relay is required.

  • Page 86: Ⅵ. Commissioning

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Ⅵ. Commissioning 1.Pre start-up (1) Electrical System Inspection 1) Inspect whether power distribution capacity is compliant with the power of the unit before the first start-up, and whether the diameter of the selected cable can bear the maximum working current of the master compressor.
  • Page 87 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 especially various wiring ports, for cleanness. If the communication lines of the PCB and control screen are damaged, refer to the diagram below. After the inspection for all the above items is complete, connect the control cabinet and the supply indication lamp will light up, indicating that the oil heater is working.
  • Page 88 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) The color is indicated in the center and compared with the color card around it to reflect the moistness in the system. Sufficient lubricating oil in the oil tank (not lower than 1/2 of the oil level in the high oil immersion lens), and no deterioration (blackness).
  • Page 89 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 terminals are firm and reliable before electrification). All connection points Inspect all terminals of terminals must be firmness firm and reliable. reliability before electrification. Inspect whether there is poor contact and short circuit caused by dust, moisture, etc. in the electrical cabinet, and whether the values of all temperature sensors are normal.

  • Page 90: Start-Up

    MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Armored dip-type temperature sensor For later armored dip-type temperature sensor, no lubricating oil is required for heat transfer. 2. Start-up Before start-up of the unit, the following performance parameters need to be inspected: (1) High/low voltage value of the system.
  • Page 91 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 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 92 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) Refrigeration Working Condition Discharge temp. ℃ 55~75℃ Suction temp. ℃ 4~13℃ Suction super-heating degree ℃ 4~10℃ Discharge super-heating degree ℃ 20~35℃ Discharge pressure MPa 1.3~1.45MPa Suction pressure MPa 0.37~0.45MPa Keep good record of unit data during commissioning.

  • Page 93: Ⅶ. Maintenance

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Ⅶ. Maintenance ATTENTION: All installation parts must be maintained by the personnel in charge, in order to avoid material deterioration and injuries to people. Faults and leaks must be repaired immediately. The authorized technician must have the responsibility to repair the fault immediately.
  • Page 94 It’s better to make maintenance agreement with local customer service centre of Midea after chiller out of warranty, to keep the chiller always under effective service and guarantee reliable operation.
  • Page 95 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 softening process or clean the tubes. Note: Keeping the normal operation parameters of initial unit commissioning is very useful. It can be used for comparative analysis to find out the trend of problem. Scheduled maintenance General Take notice of the noise at any time by standing 1m from the unit.
  • Page 96 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control)  Chilled water cycling Seek the possible leakage on the unit and the pipe joint with leak detector. Expel the water from condenser and evaporator to see whether there’s leakage on water inlet and outlet. Leak can be found with electronic detector, torch detector or soap water.
  • Page 97 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 changed in principle. Even if it is required to adjust some parameters due to special local climate, it shall be done by or under the instructions of after-sale personnel or professionals in the factory. If any exceptional case occurs to the unit, it is forbidden to forcibly start up the unit unless under the instructions of professionals.

  • Page 98: Maintenance

    DX type water-cooled screw chiller (PCB Control) 2. Maintenance If the problem is much more serious, contact your local Midea or your local representative for assistance. Cleaning Heat Exchangers Check the chiller tightness and whether there’s leak of heat exchange tubes. It is necessary to do nondestructive inspection for the principal weld (longitudinal and circumferential weld of evaporator/condenser barrel) of pressure vessel.
  • Page 99 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 100 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 101 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 triple evacuation method is recommended and is particularly helpful if the vacuum pump is unable to obtain the desired 130Pa of vacuum. The system is first evacuated to approximately 660Pa (=5mmHg). Dry nitrogen is then added to the system to bring the pressure up to zero. Then the system is once again evacuated to approximately 230Pa(=2mmHg).
  • Page 102 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) and break the vacuum with refrigerant gas to a saturated pressure above freezing. With a system gas pressure higher than the equivalent of a freezing temperature, invert the charging cylinder and elevate the drum above the condenser. With the drum in this position, valves open, water pumps operating, liquid refrigerant will flow into the condenser.
  • Page 103 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 2,000 hours. Check the system whether clean or not and then change the oil every 20,000 hours or after 3 years of continuous running while the system is operated under good condition. 2.

  • Page 104: Ⅷ. Troubleshooting

    DX type water-cooled screw chiller (PCB Control) Ⅷ. 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 105 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 If cooling water flow fails, cooling water pump and cooling tower stops after 60s delay; chilled water pump stops after 600s delay. Note: fault can be cleared after power re-energized and it needs to be confirmed manually, then when both temperature and time condition gets satisfied, the chiller can restart.
  • Page 106 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) stop according to abnormal shutdown program. After the switch reset, fault on screen must be confirmed and cleared manually; when both temperature and time condition gets satisfied, the chiller can restart.  Anti-freeze protection Over low leaving chilled water temperature When leaving chilled water temperature gets lower than 4°...

  • Page 107: Troubleshooting

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 2.Troubleshooting Trouble Alarm Action Reset Type Possible Cause Description The power quality is Phase Compressor cannot work; poor, there may exist Power Failure sequence Reset manually on the The compressor stop phase inversion, Protection relay switches touch screen...
  • Page 108 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 5,Wrong refrigerant type 6,The discharge shutoff valve does not open fully 1,The refrigerant not enough 2,EXV failure, cannot work abnormally 3,The delay time of low pressure switch 1.The compressor which alarm too short The low exists protection stop 4,There is plugging in...

  • Page 109: Ⅸ. Appendix 1

    DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 Ⅸ. Appendix 1 1.Temperature-Resistance characteristic sheet for discharge temperature sensor NTC sensor characteristic sheet Unit：Temp:℃--K.Ratio:KΩ，5K@90℃ Temp. Ratio Temp. Ratio Temp. Ratio Temp. Ratio 542.7 68.66 13.59 3.702 511.9 65.62 13.11 3.595 62.73 12.65 3.492 455.9...
  • Page 110 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 2.Temperature-Resistance characteristic sheet for water temp. sensor, ambient temp. sensor, oil temp. sensor. Unit：Temp:℃--K . Ratio:KΩ，10K@25℃ NTC sensor characteristic sheet Temp. Ratio Temp. Ratio Temp. Ratio Temp. Ratio 103.882 12.598 2.383 0.623 97.868 12.023 2.296...
  • Page 111 DX type water-cooled screw chiller (PCB Control) MCAC-CTSM-2014-03 3.Temperature-Resistance characteristic sheet for EXV temp. sensor. Unit：Temp:℃--K. Ratio:KΩ10K@25℃ NTC Sensor characteristic sheet Temp. Ratio Temp. Ratio Temp. Ratio Temp. Ratio 67.74 12.09 3.02 0.97 64.54 11.63 2.92 0.94 61.52 11.20 2.83 0.92 58.66 10.78...
  • Page 112 MCAC-CTSM-2014-03 DX type water-cooled screw chiller (PCB Control) 1. Temperature-Resistance characteristic sheet for EXV temp. sensor. Unit：Temp:℃--K. Ratio:KΩ 50K@25℃ NTC Sensor characteristic sheet Temp. Ratio Temp. Ratio Temp. Ratio Temp. Ratio 1630,77 1178,11 860,97 636,08 474,78 357,83 272,18 208,83 161,56 125,97 98,96 78,29...
  • Page 113 Commercial Air Conditioner Division Midea Group Address: Midea Headquarters Building, 6 Midea Avenue, Beijiao, Shunde, Foshan, Guangdong, China Midea CAC After-service Application Midea CAC News Application Postal code: 528311 Tel: +86-757-26338346 Fax: +86-757-22390205 cac.midea.com global.midea.com Note: The data in this book may be changed without notice for further improvement on...

This manual is also suitable for:

Lsblg255/mzLsblg400/mzLsblg630/mzLsblg860/mzLsblg485/mz

Table of Contents