Midea MWSC340A-FB3 Manual
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Midea MWSC340A-FB3 Manual

R134a 50hz l flooded type water cooled screw chiller (pcb control)
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Библиотека СОК 
Applicable Model:
Midea reserves the right to discontinue, or change specification or designs at any time without notices and
without incurring obligations.
Midea R134a 50Hz l
Flooded type water cooled
screw chiller (PCB Control)
MWSC340A-FB3
MWSC440A-FB3
MWSC540A-FB3
MWSC690A-FB3
MWSC805A-FB3
MWSC890A-FB3
MWSC1080A-FB3
MWSC1200A-FB3
MWSC1385A-FB3
MWSC1620A-FB3
MWSC1780A-FB3
DM15-01.01.18en

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Summary of Contents for Midea MWSC340A-FB3

  • Page 1 Flooded type water cooled screw chiller (PCB Control) Applicable Model: MWSC340A-FB3 MWSC1080A-FB3 MWSC440A-FB3 MWSC1200A-FB3 MWSC540A-FB3 MWSC1385A-FB3 MWSC690A-FB3 MWSC1620A-FB3 MWSC805A-FB3 MWSC1780A-FB3 MWSC890A-FB3 Midea reserves the right to discontinue, or change specification or designs at any time without notices and without incurring obligations.

  • Page 2: Table Of Contents

    Flooded type water cooled screw chiller (PCB Control) Contents I. Safety precautions ....................2 Installation safety considerations ....................2 Maintenance safety considerations ..................... 3 Repair safety considerations ....................... 4 Product ......................6 General Information ........................6 Features ............................8 Specifications ..........................13 Outline dimension ........................

  • Page 3: Safety Precautions

    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. (2) It is compulsory to wear personal protection equipment. Do not remove the skid or the packaging until the unit is in its final position.

  • Page 4: Maintenance Safety Considerations

    Flooded type water cooled screw chiller (PCB Control) Maintenance safety considerations 2.1 Engineers safety consideration (1) 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 5: Repair Safety Considerations

    Flooded type water cooled screw chiller (PCB Control) a refrigerant analysis in a specialist laboratory.  If the refrigerant circuit remains open for longer than a day after an intervention (such as a component replacement), the openings must be plugged and the circuit must be charged with nitrogen (inertia principle).
  • Page 6 Flooded type water cooled screw chiller (PCB Control)  During refrigerant removal and storage operations follow applicable regulations. These regulations, permitting conditioning and recovery of halogenated hydrocarbons under optimum quality conditions for the products and optimum safety conditions for people, property and the environment. ...

  • Page 7: Product

    Flooded type water cooled screw chiller (PCB Control) II. Product General Information 1）Product Line Up Cooling Capacity Quantity of Series Model Power Supply (kW) Compressor MWSC340A-FB3 380V/3Ph/50Hz MWSC440A-FB3 380V/3Ph/50Hz Single head MWSC540A-FB3 380V/3Ph/50Hz MWSC690A-FB3 380V/3Ph/50Hz MWSC805A-FB3 380V/3Ph/50Hz MWSC890A-FB3 380V/3Ph/50Hz MWSC1080A-FB3...
  • Page 8 Flooded type water cooled screw chiller (PCB Control) 3). External appearance Single head(MWSC340A-FB3~ MWSC890A-FB3) Dual head(MWSC1080A-FB3~ MWSC1780A-FB3)

  • Page 9: Features

    Flooded type water cooled screw chiller (PCB Control) Features High efficiency  High efficiency inner grooved copper pipe enhances the heat-exchange process, improves heat exchange efficiency and makes the evaporator more compact to save installation space.  Significantly improve the evaporating temperature and reduce heat transferring temperature difference which directly improves heat-exchange efficiency, provide most cost effective &...
  • Page 10 SKF brand industry use bearing guarantees 60,000h continuous working Advanced twin-rotor screw compressor Midea® Screw Chiller equipped with the 3rd generation industrial Semi-hermetic Screw compressor that has the latest advanced 5-6 asymmetry dentiform rotors. The rotors are processed by high-precision CNC and each part is well-proportioned and none-gap matching, which minimize the...
  • Page 11 Flooded type water cooled screw chiller (PCB Control)  High-precision machining and measurement make rotor clearance reach μm-class, so it reduces the leakage between high and low pressure. Under continuous operation, the rotors still keep their best clearance and achieve highest efficiency. ...
  • Page 12 Condenser  Midea condenser has a specially designed baffle, in the entrance of condenser, to prevent direct impingement of high-velocity refrigerant gas on tube surface and thus eliminate the related vibration and noise. It has been tested under extreme conditions. Water side working pressure is designed for 1.0Mpa (Higher pressure vessels can be customized).
  • Page 13 Flooded type water cooled screw chiller (PCB Control) mixed state and enters the lower part of the evaporator. It is then spread into a wider surface by distributor. Finally the distributed refrigerant evaporates by taking the heat from the chilled water inside the evaporator tube and repeats the cycle.

  • Page 14: Specifications

    Flooded type water cooled screw chiller (PCB Control) Specifications Single head MWSC_A-FB3 Cooling capacity Power input kW/kW 5.66 5.71 5.74 5.75 5.75 5.74 Semi-hermetic screw compressor Circuit A Quantity Circuit B Quantity Oil recharge Circuit A Circuit B Refrigerant Type R134a Circuit A Circuit B...
  • Page 15 Flooded type water cooled screw chiller (PCB Control) Dual head MWSC_A-FB3 1080 1200 1385 1620 1780 Cooling capacity 1080 1200 1385 1620 1780 Power input kW/kW 5.82 5.81 5.82 5.81 Semi-hermetic screw compressor Circuit A Quantity Circuit B Quantity Oil recharge Circuit A Circuit B Refrigerant...

  • Page 16: Outline Dimension

    Chilled Cooling water outlet water inlet Unit: mm Water Ａ Ｂ Ｃ Ｄ Ｅ Ｆ Ｇ Ｈ Model inlet/outlet Dim. MWSC340A-FB3 3550 1220 1730 2850 1100 DN150 MWSC440A-FB3 3550 1220 1800 2850 1100 DN150 MWSC540A-FB3 3550 1220 1900 2850 1100...

  • Page 17: Refrigeration System

    Flooded type water cooled screw chiller (PCB Control) Refrigeration system For single head unit( MWSC340~890A-FB3) For dual heads unit (MWSC1080~1780A-FB3)

  • Page 18: Major System Components

    6.1 Advanced twin screw compressor  Midea screw chiller 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 matching, which minimizes the friction resistance and clearance lost, guarantees quiet running and good duration.
  • Page 19 Flooded type water cooled screw chiller (PCB Control)  Lubricant: The lubricant is supplied automatically by pressure difference inside the compressor. It is unnecessary to add an extra lubricant pump. The compressor is approved for use with the following lubricant: HBR-B04 for R134a unit ...
  • Page 20 Flooded type water cooled screw chiller (PCB Control) 6.2 Pressure vessels 6.2.1 General Monitoring during operation, re-qualification, re-testing and re-testing dispensation:  Follow the regulations on monitoring pressurized equipment.  It is normally required that the user or operator sets up and maintains a monitoring and maintenance file.
  • Page 21 Flooded type water cooled screw chiller (PCB Control) Ball valve can protect life and property because it can prevent refrigerant from flowing into the air when safety valve is opening or replaced. 6.2.6 Evaporator Gas refrigerant Chilled water outlet Chilled water inlet Liquid refrigerant Tube...

  • Page 22: Water Flow

    The chiller control set points are based upon a constant flow and variable temperature. Evaporator water flow rate Condenser water flow rate Model Rated Minimum Maximum Rated Minimum Maximum MWSC340A-FB3 MWSC440A-FB3 MWSC540A-FB3 MWSC690A-FB3 MWSC805A-FB3 MWSC890A-FB3 MWSC1080A-FB3 MWSC1200A-FB3 MWSC1385A-FB3 MWSC1650A-FB3...
  • Page 23 Flooded type water cooled screw chiller (PCB Control) Water pressure drop curve(evaporator) MWSC1080A-FB3 MWSC1200A-FB3 MWSC1385A-FB3 MWSC1620A-FB3 MWSC1780A-FB3 Water flow (m3/h) Flooded type (Condenser) Water pressure drop curve(condenser) MWSC340A-FB3 MWSC440A-FB3 MWSC540A-FB3 MWSC690A-FB3 MWSC805A-FB3 MWSC890A-FB3 220 Water flow (m3/h) Water pressure drop curve(condenser) MWSC1080A-FB3 MWSC1200A-FB3...
  • Page 24 Flooded type water cooled screw chiller (PCB Control) System minimum water volume Water volume is necessary for stable operation. It is often necessary to add a buffer water tank to the circuit in order to achieve the required volume. The tank must itself be internally baffled in order to ensure proper mixing of the liquid (water or brine).

  • Page 25: Operating Range

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

  • Page 26: Capacity Table

    Flooded type water cooled screw chiller (PCB Control) Capacity table MWSC340A-FB3 Cooling Water Inlet(° 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...
  • Page 27 Flooded type water cooled screw chiller (PCB Control) MWSC540A-FB3 Cooling Water Inlet(° 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 28 Flooded type water cooled screw chiller (PCB Control) MWSC805A-FB3 Cooling Water Inlet(° C) Chilled 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Water Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 29 Flooded type water cooled screw chiller (PCB Control) MWSC1080A-FB3 Cooling Water Inlet(° C) Chilled 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Water Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 30 Flooded type water cooled screw chiller (PCB Control) MWSC1385A-FB3 Cooling Water Inlet(° C) Chilled 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Water Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...
  • Page 31 Flooded type water cooled screw chiller (PCB Control) MWSC1780A-FB3 Cooling Water Inlet(° C) Chilled 25.00 26.00 27.00 29.00 30.00 32.00 33.00 35.00 Water Outlet Temp. Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power (°...

  • Page 32: Accessories

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

  • Page 33: Control

    Flooded type water cooled screw chiller (PCB Control) III. Control Control flow chart 2 Compressors 380VAC Double-Head 3P+N+PE Compressor Compressor Thermorelay Thermorelay Miniature 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 34: Energy Adjustment

    Flooded type water cooled screw chiller (PCB Control) Energy adjustment The unit adjust capacity by chilled water. The control logic see picture. Energy adjustment is districted when starting high pressure is too high. High pressure unloading 19Bar 18Bar Normal adjusting...

  • Page 35: Start/Stop Process

    Flooded type water cooled screw chiller (PCB Control) Start/stop process 1).cooling start Power-on Clear failure Detect fault Start on Chilled pump on Cooling pump on cooling tower on Water flow Stop Clear failure switch protection Water temp is ok. Stand heating time enough...

  • Page 36: Sensors

    Flooded type water cooled screw chiller (PCB Control) 2).cooling stop stop Running time Stand 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 Sensors 1).Temperature sensors The temperature sensors that unit use are all NTC thermistors, including chilled leaving water temperature, chilled entering water temperature, discharge temperature, EXV discharge temperature.

  • Page 37: Parts Control

    Flooded type water cooled screw chiller (PCB Control) electric control wiring diagram for detail connection information.  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.
  • Page 38 Flooded type water cooled screw chiller (PCB Control)  When cooling water inlet temperature >= 20° C (real time value), oil heating time for first startup is 4hrs. If power down happens during operation and downtime is less than 1hrs, no heating time delay is needed when unit restarts.
  • Page 39 Flooded type water cooled screw chiller (PCB Control) 32min 32min 12Bar 12Bar 12Bar a. When compressor start, the return oil solenoid valve is opened ,closed after 10 minutes. b. When compressor is running ,from compressor start to 50%,every 30 minutes to open return oil solenoid valve 2 minutes.
  • Page 40 Flooded type water cooled screw chiller (PCB Control) power supply Display suction superheat Display EXV opening Relay output status Alarm Start of the protection If the parameter need to be displayed and set. Interface should be changed. Remove cover Change display Display...
  • Page 41 Flooded type water cooled screw chiller (PCB Control) Button Function Control state Open the display screen, enter the password to enter the programming mode • In the alarm state, the display alerts the queue; • When the "producer" level under the rolling parameters, the display shows the interface •...
  • Page 42 Flooded type water cooled screw chiller (PCB Control) ⑧Press ENTER to save the new parameter values; ⑨Repeat the above 5, 6, 7, 8 step change other parameters; ⑩Press Esc to exit the repair parameters modify the program. The following shows the detailed settings: 13 pages Drive hardware configuration 1/13 Drive hardware configuration...
  • Page 43 Flooded type water cooled screw chiller (PCB Control) - he special parameters - lert configuration parameters - Valve parameters ⑤Press UP/DOWN button to select the category, and then press ENTER to enter the first class number ⑥Press UP/DOWN to select parameters to be set, and then press ENTER to move to the parameter value;...
  • Page 44 Flooded type water cooled screw chiller (PCB Control) PID: proportional gain PID: integration time PID: derivation time Minimum number of valve steps Maximum number of valve steps 3810 Number of steps for valve closing 3970 Valve rate LowSH protection: threshold LowSH protection: integration time LOP protection: threshold LOP protection: integration time...

  • Page 45: Operation Part

    Flooded type water cooled screw chiller (PCB Control) 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 46 Flooded type water cooled screw chiller (PCB Control) 6.2 Operation part The control system adopts touch screen, and all the operation is done on the screen directly. Take the unit with dual compressors and step control as example, the actual display of different product may have a little difference, but basically the operation is the same.
  • Page 47 Flooded type water cooled screw chiller (PCB Control) 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 48 Flooded type water cooled screw chiller (PCB Control) "X" at the top right to close the pop-up window. ①Only control mode can be switched during operating, other mode selection is invalid. ② The control mode is used as on/off mode choice. "Local” control mode can only be realized through the touch screen "on / off"...
  • Page 49 Flooded 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 50 Flooded type water cooled screw chiller (PCB Control) temperature, compressor starts. Heating mode: water temperature of paused state= setting chilled water temperature+ temperature control range. When unit is in paused state, if temperature controlling is lower than compressor starting temperature, compressor starts. ...
  • Page 51 Flooded type water cooled screw chiller (PCB Control) ⑧ Display if the starting temperature is satisfied, when compressor starts, it need to be satisfied that water temperature is satisfied with “compressor start” is‘ＹＥＳ’; ⑨ Display if the delay restart is satisfy, when compressor starts, it need to be satisfied that “delay restart”...
  • Page 52 Flooded type water cooled screw chiller (PCB Control) Figure 6.8 (Remark: subject to the actual principle diagrams) ① “Remote start/stop”, it displays the status of remote start or remote stop. User needs to install the point contact type control switch. ②...
  • Page 53 Flooded type water cooled screw chiller (PCB Control) Figure 6.10 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  User parameter setting-temperature setting Input the password （40828）and enter the page as figure 6.12 as below: Manual input is...
  • Page 54 Flooded type water cooled screw chiller (PCB Control) ① The temperature adjustment cycle： it represents each execution cycle of the judgment of load or unload. If it is set to be 60S, that means every 60 seconds system judges the unit temperature and check if it needs to load or unload.
  • Page 55 Flooded type water cooled screw chiller (PCB Control) appear. Press adjust Figure 6.14 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.
  • Page 56 Flooded type water cooled screw chiller (PCB Control)  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 57 Flooded type water cooled screw chiller (PCB Control) Figure 6.17 Please refers to the actual operation interface; it is subject to change without notice.

  • Page 58: Safety Protection

    Flooded type water cooled screw chiller (PCB Control) Safety protection Name Code Brand Setting Range Location ON 0.10Mpa Low-pressure YK-0.3/0.20- JUNLE OFF 0.20Mpa Switch O-R-7000 ON 1.4Mpa High-pressure YK-1.4/0.9-C- JUNLE OFF 0.9Mpa Switch 1 R-7000 Note: Manual reset is needed for high-pressure switch. Safety Devices ...
  • Page 59 Flooded type water cooled screw chiller (PCB Control)  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 MWSC_A-FB3 14bar 9bar...

  • Page 60: Electrical Control

    Flooded type water cooled screw chiller (PCB Control) IV. Electrical control Electrical data LSBLGWXXX/MCF 1120 1230 1500 Standard voltage 380V~3Ph~50Hz+N+PE Voltage range 342~418 Max. running current Max. power consumption 93.5 116.8 141.9 182.9 205.8 283.8 215.8 365.8 Rated current Compressor A Locked rotor Amps.

  • Page 61: Electrical Components Introduction

    Flooded type water cooled screw chiller (PCB Control) Electrical components introduction 1) Power protector This module is used to detect power supply and provide protection in case of phase loss, phase sequence, and under voltage of incoming line power, so as to prevent damage to the compressor or other components caused by power failure.
  • Page 62 Flooded type water cooled screw chiller (PCB Control)

  • Page 63: Electrical Parts Parameter Setting

    Flooded type water cooled screw chiller (PCB Control) 5) Electronic Expansion Valve The electronic expansion valve is equipped with a stepping motor which controls the valve status. A special-purpose electronic expansion valve control module is required to drive the electronic expansion valve.
  • Page 64 Flooded type water cooled screw chiller (PCB Control) 2) Time Relay Time’s up LED Up display green Power LED On display red T： 6S Time relay use Omron H3Y type. 3) Compressor and fan thermal overload relay Thermal overload relay takes advantage of heating effect to protect the compressor and fans. TEST key: to press to test whether the overload relay is normal in stop condition Reset key: to press to reset the overload...

  • Page 65: Field Wiring

    Flooded type water cooled screw chiller (PCB Control) 1780 370.8x2 500/5 Field wiring 1) Wiring diagram Power supply wiring diagram...
  • Page 66 Flooded type water cooled screw chiller (PCB Control) Water Pump Wiring Diagram 3～ Recommended external wiring cable Unit Model External wiring cable (mm2) Unit Model External wiring cable (mm2) MWSC340A-FB3 MWSC1080A-FB3 4×AWG1+AWG3 4×AWG400+AWG4/0 MWSC440A-FB3 MWSC1200A-FB3 4×AWG1/0+AWG3 4×AWG500+AWG250 MWSC540A-FB3 MWSC1385A-FB3 4×AWG3/0+AWG1 4×AWG600+AWG300...
  • Page 67 Flooded type water cooled screw chiller (PCB Control) 2) 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. Only double head Customer wiring terminal Inside electric control cabinet...

  • Page 68: Wiring Diagrams

    Flooded type water cooled screw chiller (PCB Control) Wiring Diagrams MWSC340~890A-FB3 L1 L2 L3 1/G2 2/F2 12 11 14 2/B9 2/B9 ～ X:23 24V 0V 220V +V -V X:24 RS485 Communication Line JTX-A 3～ 3/F2 N S1 S2 M1 M2 1/G2 2/F2...
  • Page 69 Flooded type water cooled screw chiller (PCB Control) X:39 X:13 X:14 X:42 X:45 X:47 SP2 SP1 X:40 X:12 X:15 X:41 X:43 X:44 X:46 X:48 206 208 218 220 309 311 313 315 X:27 X:31 X:33 X:35 X:5 YV3 YV2 YV1 X:28 X:32 X:34 3/E2...
  • Page 70 Flooded type water cooled screw chiller (PCB Control) ～ 220V X:50 X:51 X:54 X:55 X:58 X:62 X:17 X:18 X:20 +V -V X:16 X:19 X:21 X:49 X:52 X:53 X:56 X:57 X:61 230 234 402 404 406 410 404 317 319 X:8 X:9 X:10 2/F11 2/F11...
  • Page 71 Flooded type water cooled screw chiller (PCB Control) 1/C12 1/F12 613 615 605 603 601 607 X:69 X:68 X:67 X:70 BP P...
  • Page 72 Flooded type water cooled screw chiller (PCB Control) MWSC1080~1780A-FB3 L1 L2 L3 12 11 14 1/G2 1/G4 2/B2 1TA1 1TA2 2TA2 2TA1 3/B9 3/B9 1KM1 2KM1 ～ 220V +V -V X:29 X:32 24V 0V 1KM1 1KM2 2KM1 2KM2 RS485 Communication Line 4/F2 X:30 X:31...
  • Page 73 Flooded type water cooled screw chiller (PCB Control) 1/C11 3/F2 4/A5 5/B1 1KM3 2KM3 1KM2 2KM2 1KM3 1KM1 2KM3 2KM1 1KM2 2KM2 1KM1 1KM2 1KM3 2KM1 2KM2 2KM3 1/E11 3/F2 4/A5 5/B1...
  • Page 74 Flooded type water cooled screw chiller (PCB Control) X:65 X:53 X:18 X:19 X:56 X:59 X:62 1SP2 1SP1 2SP2 2SP1 X:52 X:54 X:17 X:20 X:55 X:57 X:58 X:60 X:61 X:63 X:64 X:66 208 210 224 226 228 230 309 311 313 323 325 327 329 X:35 X:37...
  • Page 75 Flooded type water cooled screw chiller (PCB Control) ～ X:22 X:23 X:25 X:67 220V X:78 X:82 X:83 X:70 X:71 X:74 X:75 X:79 +V -V X:21 X:24 X:68 X:69 X:76 X:77 X:81 X:84 X:72 X:73 X:80 X:26 240 248 402 404 406 410 404 331 333 X:12 X:13...
  • Page 76 Flooded type water cooled screw chiller (PCB Control) 2/B12 2/E12 613 615 631 633 2EVD 1EVD 605 603 601 607 623 621 619 625 X:104 X:95 X:94 X:93 X:96 X:103 X:102 X:101 2BP P...

  • Page 77: Installation

    Flooded 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 78 Flooded type water cooled screw chiller (PCB Control) 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. It is suggested to consult the building designer before installation. ②...
  • Page 79 ≥ Expected load bearing value listed below: Isolation pad Vibration Isolator Running Model Minimum load Minimum Minimum load weight(kg) Quantity bearing (kg/EA) Quantity bearing (kg/EA) MWSC340A-FB3 2700 MWSC440A-FB3 1000 1000 2820 MWSC540A-FB3 1200 1200 3220 MWSC690A-FB3 1400 1400 3870 MWSC805A-FB3...

  • Page 80: Water Pipeline System Installation

    Flooded type water cooled screw chiller (PCB Control) (1) Pads have to extend the full length of the saddle when isolation pad be used. (2) Level the unit to within 5mm over through it’s length and width after absorbers installed. 4).Spaces ○...
  • Page 81 Flooded type water cooled screw chiller (PCB Control) Ethylene and Propylene Glycol Factors A glycol solution is required when the unit with condition as mentioned. The use of glycol will reduce the performance of the unit depending on concentration. Ethylene Glycol Evaporator side Cooling Quality of...
  • Page 82 Flooded type water cooled screw chiller (PCB Control) Evaporator temperature drop factors Performance tables are based on a 5 C temperature drop through the evaporator. Adjustment factors for applications with temperature ranges from 3 ℃ to 6 ℃ in follow table. Temperature drops outside this range can affect the control system’s capability to maintain acceptable control and are not recommended.
  • Page 83 Flooded type water cooled screw chiller (PCB Control) guided by design professionals, and confirm to the corresponding provisions of the HVAC installation specifications. Basically, the piping should be designed with a minimum number of bends and changes in elevation to keep system cost down and performance up.
  • Page 84 Flooded type water cooled screw chiller (PCB Control) outlet side. 4) The chilled water pipeline system must be provided with the soft connection, thermometer, pressure gauge, water filter, electronic scale remover, check valve, target flow controller, discharge valve, drain valve, stop valve, expansion tank, etc. 3) The water system must be fitted with the water pump with appropriate displacement and head, so as to ensure normal water supply to the unit.
  • Page 85 Flooded type water cooled screw chiller (PCB Control) decreasing the performance of the evaporator. 6) A strainer should be placed for enough upstream to prevent cavitation at the pump inlet (consult pump manufacturer for recommendations). The use of a strainer will prolong pump life and help maintain high system performance levels The flushing and insulation of the water pipelines shall be carried out before it is connected with the unit, so as to prevent dirt from damaging the unit.

  • Page 86: Wiring Installation

    Flooded type water cooled screw chiller (PCB Control) checking the leaving evaporator water temperature. Note: The unit only supplies the ON/OFF signal, but not the 220V power. If a separate disconnect is used for the 220V supply to the cooler heating cable, it should be clearly marked so that it is not accidentally shut off during cold seasons.
  • Page 87 Flooded type water cooled screw chiller (PCB Control) Power section: It is required to connect the power supply cable to the control cabinet of the unit, when it arrives at the jobsite. The power supply cable is connected to the terminals of L1, L2, L3, N and PE and the terminals need to be fixed again after 24h running (the minimum allowed time).

  • Page 88: Commissioning

    Flooded type water cooled screw chiller (PCB Control) VI. Commissioning 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 89 Flooded type water cooled screw chiller (PCB Control) 9) Before start up the machine, inspect whether the external system of the unit meets the conditions for start-up (e.g. whether the water cooling pump of the system is externally controlled or interlocked with the master compressor, and that the water pump must be started before starting up the master compressor via external control).
  • Page 90 Flooded type water cooled screw chiller (PCB Control) The oil must be full in stop status of the unit, and above the 1/2 position in stable operation. When the unit is in stable operation, the oil level in the high oil immersion lens should be at least above the 1/2 position.
  • Page 91 Flooded type water cooled screw chiller (PCB Control) and the entering and leaving chilled water temperatures shall be almost the same. 10) Before the unit leaves the factory, the control cabinet is well connected with main motor, electrical actuator, and sensor elements of pressure temperature, etc. Therefore, the wiring on site for the user is very simple.

  • Page 92: Start-Up

    Flooded type water cooled screw chiller (PCB Control) Start-up Before start-up of the unit, the following performance parameters need to be inspected: (1) High/low voltage value of the system. For the unit shut down and waterless in a long term, the liquid and gas of the system shall be equivalent and close to the saturation pressure corresponding to the current ambient temperature.
  • Page 93 Flooded type water cooled screw chiller (PCB Control) Compressor oil heater begins to work when the unit is electrified. (3) Inspect whether there is alarm for trouble of the display screen. if there is, the trouble must be corrected. (4) Inspect the electronic expansion valve control module for alarm trouble. (5) Inspect whether various temperature points displayed on the display screen are within the normal range.

  • Page 94: Maintenance

    Flooded type water cooled screw chiller (PCB Control) 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 95 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 96 Flooded type water cooled screw chiller (PCB Control) operation. It’s good for finding and forecasting the problem that may occur and taking measures in time. For example, by analyzing the record of a whole month, you may find that the temperature difference of condensing temperature and leaving cooling water temperature may become bigger.
  • Page 97 Flooded type water cooled screw chiller (PCB Control) whether there is corrosion, rust, scaling, leakage phenomenon internal (if necessary, replace the safety valve). And also check other operating valves to see whether it’s smooth when opening or closing them. ▲ High/low pressure switch Check their performance whether they are in good condition according to “performance of protection device”...

  • Page 98: Maintenace

    Maintenace 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 Flooded type water cooled screw chiller (PCB Control) Refrigerant Circuit  Leak testing Units are factory-charged with refrigerant R-22 (Refer to the Physical Data tables supplied in the IOM manual book). Leak test must be done under sufficient pressure. This can be done by charging enough refrigerant into the system to build the pressure up to approximately 70 kPa and adding sufficient dry nitrogen to bring the pressure up to a maximum of 850 kPa.
  • Page 102 Flooded type water cooled screw chiller (PCB Control) Refer to Physical Data tables supplied in the IOM manual book). Immediately ahead of orifice baffle (see Fig.) is a factory-installed liquid line service angle valve. Each angle valve has a1 5/8-in. threaded connection for charging liquid refrigerant.
  • Page 103 Flooded type water cooled screw chiller (PCB Control) charge Quantities. Fig. 34. Each screw compressor is connected to a tank (oil separator) separating and collecting the oil from discharge gas. The discharge gas pressure pushes the oil back into the compressor for compressor seal and lubrication of all moving parts.
  • Page 104 Flooded type water cooled screw chiller (PCB Control)  Oil change 1. Change oil periodically: Check the lubrication oil for every 10,000 hours of continuous running. For the first operation of the compressor, it is recommended to change oil and clean oil filter after running at 2,000 hours.

  • Page 105: Troubleshooting

    Troubleshooting Protection items 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 106 Flooded type water cooled screw chiller (PCB Control) If chilled water flow fails, chilled water pump stops after 30s delay; cooling water pump and cooling tower stops after 60s delay. If cooling water flow fails, cooling water pump and cooling tower stops after 60s delay; chilled water pump stops after 600s delay.
  • Page 107 Flooded type water cooled screw chiller (PCB Control) fault happens. Fault on screen must be confirmed and cleared manually; when both temperature and time condition gets satisfied, the chiller can restart. When suction pressure is lower than the protective low pressure set point (effective for time delay), stop according to abnormal shutdown program.

  • Page 108: Troubleshooting

    Flooded type water cooled screw chiller (PCB Control) Troubleshooting Alarm Trouble Description Action Reset Type Possible Cause Compressor cannot work; The Power Failure Phase sequence relay Reset manually on the touch The power quality is poor, there may exist phase compressor stop running Protection switches OFF...
  • Page 109 Flooded type water cooled screw chiller (PCB Control) 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 The compressor which exists system High-pressure protection stop running Press red reset button, reset High pressure switch OFF 3,The cooling water flow too small or the...
  • Page 110 Flooded type water cooled screw chiller (PCB Control) 1,The superheat too high( the refrigerant not enough, EXV failure) The protection is relieved once 2,The discharge pressure too high The compressor which exists The compressor discharge the discharge temperature is 3,The oil level too low and the oil volume in the High Discharge protection stop running temperature is greater than...
  • Page 111 Flooded type water cooled screw chiller (PCB Control) 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 112 Flooded 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 113 Flooded type water cooled screw chiller (PCB Control) 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 114 Flooded type water cooled screw chiller (PCB Control) 4. 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...

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