Danfoss ADAP-KOOL AK-PC 781 Design Manual
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Danfoss ADAP-KOOL AK-PC 781 Design Manual

Capacity controller with heat recovery function, refrigeration control systems
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Design Guide
Capacity controller with
heat recovery function
AK-PC 781
ADAP-KOOL® Refrigeration control systems

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Summary of Contents for Danfoss ADAP-KOOL AK-PC 781

  • Page 1 Design Guide Capacity controller with heat recovery function AK-PC 781 ADAP-KOOL® Refrigeration control systems...

  • Page 2: Table Of Contents

    Appendix B - Alarm texts ..............136 Setup control of receiver pressure ..........66 Appendix C - Recommended connection - AK-PC 781 ...138 Setup control of heat recovery..........67 Setup Display ..................70 Setup Functions for General purpose ........71 Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 3: Introduction

    - Alarms are shown with texts so that the cause of the alarm is easy to see. - Plus some completely separate functions that are totally inde- pendent of the regulation – such as alarm, thermostat ,pressure and PI-regulating functions. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 4: Principles

    A regulation with few connections can If there are many connections one or more exten- Examples be performed with the controller module sion modules have to be mounted alone Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 5 S7 gas cooler tempera- ture, hot tap water at heat recovery and heat exchanger tempera- ture at heat recovery. A graphical display with control buttons can also be fitted. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 6 One example may be slow clogging-up of a condenser. When the alarm comes the capacity has been reduced, but the situation is not serious. There will be time to plan a service call. Error Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 7: Design Of A Controller

    This section will give you a survey of possible connections plus assistance in selecting the modules required by your actual ap- plication. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 8: Module Survey

    Extension module with 2x analog output signals If the row of modules needs to be interrupted due to length or external positioning, a communi- cation module should be used. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 9 Accessories Communication modules for controllers where modules cannot be connected continuously Data communication for external extension AK-CM 102 Communication module modules On the following pages there is data specific to each module. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 10: Common Data For Modules

    UL file number: E166834 for XM and CM-modules UL 873, UL file number: E31024 for PC-modules The mentioned data applies to all modules. If data is specific, this is mentioned together with the module in question. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 11 Modules in the 100-series consist of one module Modules in the 200-series consist of two modules Controllers consist of three modules The length of an aggregate unit = n x 72 + 8 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 12: Controller

    - 2 LED’s that are not used A small module (option board) can be placed on the bottom part • “Service Pin” switch has been activated of the controller. The module is described later in the document. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 13 42 - 43 - 44 Defrost Solenoid 18 (DO7) 45 - 46 - 47 valve 19 (DO8) 48 - 49 - 50 Option Board Please see the signal on the page with the module. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 14: Extension Module Ak-Xm 101A

    5 V output or the 12 V output depending on transmitter type. Light-emitting diodes Only the two top LED’s are used. They indicate the following: • Voltage supply to the module • Communication with the controller is active (red = error) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 15 5 (AI 5) 17 - 18 switch Closed Day/ 6 (AI 6) 19 - 20 Night Open Door 7 (AI 7) 21 - 22 Level switch 8 (AI 8) 23 - 24 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 16: Extension Module Ak-Xm 102A / Ak-Xm 102B

    • Communication with the controller is active (red = error) Off: DI < 2 V a.c. Off: DI < 24 V a.c. • Status of the individual inputs 1 to 8 (when lit = voltage) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 17 5 - 6 4 (DI 4) 7 - 8 5 (DI 5) 9 - 10 6 (DI 6) 11 - 12 7 (DI 7) 13 - 14 8 (DI 8) 15 - 16 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 18: Extension Module Ak-Xm 103A

    The outlets AO1 and AO2 are galvanically separated from AO3 and AO4. Light-emitting diodes Only the two top LED’s are used. They indicate the following: • Voltage supply to the module • Communication with the controller is active (red = error) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 19 17 - 18 Main switch Closed 6 (AO 2) 19 - 20 Day/ Night Open 7 (AO 3) 21 - 22 Door 8 (AO 4) 23 - 24 Level switch 0-10 V AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 20: Extension Module Ak-Xm 204A / Ak-Xm 204B

    Without this safety relay, the controller will fail to stop the compressor if it should run out of oil. See Regulating functions. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 21 34 -36 5 (DO 5) 37 - 39 6 (DO 6) 40 - 41 - 42 7 (DO 7) 43 - 44 - 45 8 (DO 8) 46 - 47 - 48 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 22: Extension Module Ak-Xm 205A / Ak-Xm 205B

    Without this safety relay, the controller will fail to stop the compressor if it should run out of oil. See Regulating functions. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 23 37 - 36 - 39 Light Rail heat 14 (DO6) 40 - 41 - 42 Defrost Solenoid 15 (DO7) 43 - 44 - 45 valve 16 (DO8) 46 - 47 - 48 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 24: Extension Module Ak-Xm 208C

    • Voltage supply to the module • Communication active with the bottom PC board (red = error) • Status of outputs step1 to step4 Output: 24 V d.c. = 500 m A / coil max. 20-500 step/s Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 25 Black Green KVS 42-54 Valve Module Step Terminal 1 (point 9) 25 - 28 2 (point 10) 29 - 32 3 (point 11) 33 - 36 4 (point 12) 37 - 40 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 26: Extension Module Ak-Ob 110

    The two outputs have points 24 and 25. They are shown on the earlier page where the controller is also mentioned. Max. load I < 2.5 mA R > 4 kohm Module Point 0 - 10 V Type Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 27: Extension Module Ak-Ob 101A

    The working life of the battery is several years – even if there are frequent power failures. An alarm is generated when the battery has to be replaced. After the alarm there are still several months of operating hours left in the battery. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 28: Extension Module Eka 163B / Eka 164B / Eka 166

    Placing The display can be placed at a distance of up to 3 m from the controller. Point No point has to be defined for a display – you simply connect it. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 29: Power Supply Module Ak-Ps 075 / 150 / 250

    2.5 A 60 VA Dimension Type High Width AK-PS 075 90 mm 36 mm AK-PS 150 90 mm 54 mm AK-PS 250 90 mm 72 mm Connections AK-PS 075 AK-PS 150 AK-PS 250 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 30: Communication Module Ak-Cm 102

    The controller should permanently be set to = ON. Warning Additional modules may only be installed following the installa- tion of the final module. (Here following module no. 11; see the sketch.) After configuration, the address must not be changed. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 31 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 32: Preface To Design

    The requirements to the installation are described in a separate Alarm function document. If the alarm is to be sent to a signal transmitter, a relay output will have to be used. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 33: Connections

    + 11 modules). ✔ No more than 5 pressure transmitters may be connected to one controller module. ✔ No more than 5 pressure transmitters may be connected to one extension module. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 34: Design Of A Compressor And Condenser Control

    Heat recovery function for tap water control Oil management Heat recovery function for heating Oil injection in compressor. Shared or individual Controlling the gas cooler (high pressure valve). parallel valve, if applicable Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 35: Connections

    Shr2, 3, 4 and 8 (temperature sensors for heat recovery) • Sd (discharge gas temperature) Must be used when adjusting the heat receiver for heating. Must always be used in connection with compressor regulation. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 36 • Pc regulates based on temperature sensor Sc3 and Sgc Receivers: • Monitoring of CO2 level • Control of pressure in oil receiver • Controlling the tap water receiver temperature, 55°C • Controlling the receiver temperature for the heating circuit, 40°C Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 37: Planning Table

    ___ pcs. á 5 VA = __ AK_OB 110 (2 analog outputs) ___ pcs. á 0 VA = 0 1 pcs. á 8 VA = 8 Sum = Sum = max. 32 VA AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 38: Length

    DIN rail – no matter where in the row the module is found. Removal is likewise carried out with the two catches in the open position. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 39: Determine The Connection Points

    10 (step 2) 29 - 30 - 31 - 32 11 (step 3) 33 - 34 - 35 - 36 12 (step 4) 37 - 38 - 39 - 40 Continued next page AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 40: Connection Diagram

    Drawings of the individual modules may be pressure signal. ordered from Danfoss. Format = dwg and dxf. You may then yourself write the module number in the circle and draw the individual connections. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 41 Example continued: AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 42: Supply Voltage

    UPS. Example continued: Controller module 8 VA + 2 extension modules in 200 series 10 VA + 2 extension modules in 100 series 4 VA ------ Power supply size (least) 22 VA Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 43: Ordering

    Real time clock with battery backup. To be mounted in an AK controller Accessories Communication modules for controllers where modules cannot be connected continuously 080Z0064 AK-CM 102 Communication module Data communication for external extension modules AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 44 Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 45: Mounting And Wiring

    • AK-XM 205A input and output module • AK-XM 208C analog input module + stepper output module • AK-XM 102B digital input module • AK-XM 103B analog input and output module • AK-OB 110 analog output module AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 46: Mounting

    Lift the top part off the basic module. 2. Mount the extension module in the basic module There are two outputs. 3. Put the top part back on the basic module Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 47: Mounting Of Extension Module On The Basic Module

    DIN rail – regard- less of where the module is on the row. Disassembly is thus done with the two snap catches in the open posi- tion. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 48: Wiring

    25 - 26 - 27 - 28 CCM (ETS) 10 (step 2) 29 - 30 - 31 - 32 11 (step 3) 33 - 34 - 35 - 36 12 (step 4) 37 - 38 - 39 - 40 Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 49 The screen on the pressure transmitter cables must only be connected at the end of the controller. The supply voltage for the pressure transmitter should be taken from the same module that receives the pressure signal. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 50 ■ Service Pin 5. When there is a network Network installation Set the address and activate the Service Pin. Status on output 1-8 6. The controller is now ready to be configured. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 51: Configuration And Operation

    We have decided to work on the basis of the example we went through previously, i.e. compressor control with 4 compressors and high pressure control using heat recovery and gas cooler. The example is shown two pages in. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 52: Configuration

    The red alarm bell at the bottom right tells you that there is an active alarm in the controller. In our case the alarm is due to the fact that the time in the controller has not yet been set. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 53 • SH min = 5 °C, SH max = 35 °C • Monitoring of low and high level in oil receiver Other • Start/stop of heat recovery tw and hr • External compressor stop used AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 54: Authorization

    You will access the login display by pressing the padlock at the top left corner of the display. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 55: Unlock The Configuration Of The Controllers

    The values can be changed when it is locked, but only for those settings that do not affect the configuration. 2. Select Lock/Unlock configuration 3. Select Configuration lock Press the blue field with the text Locked 4. Select Unlocked Select Unlocked. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 56: System Setup

    When the controller is connected to a net- work, date and time will automatically be set by the system unit in the network. This also applies to change-over Daylight saving. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 57: Set Plant Type

    5 – Quick relative setup Fine adjustments can be made if necessary. Smart = Setting the controller’s overall pressure values. The remaining pressure values will be set automatically. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 58: Set Control Of Compressors

    LT Coord: LT-control. A signal must both be received and sent. MT Coord release before start: LT starts and MT following. A signal must be both received and sent. LT-Comp.request delay LT-control. Delay on output signal to MT Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 59 Main step Press the +-button to go on to the Set the nominal capacity of the main step (Set the percent- next page age of the relevant compressor’s nominal capacity) 0 - 100%. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 60 Select the function if a liquid injection is required in the suction line in order to keep the discharge gas temperature down. Regulation can be done either using a solenoid valve and a TEV, or using an AKV valve. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 61: Set Oil Management

    (Forced controlled to ON with the setting "Manual" or with the "changeover" on an extension module.) Danfoss recommends this function to avoid any compres- 3. Set refrigeration circuit sor damages due to lack of care. We do not use safety relays in our (In order to keep things simple, this function is not used as example.
  • Page 62 ("high" level contact not activated) No of periods No. of times the valve should open in emptying sequence Period time Time between valve openings. Open time The open time of the valve Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 63: Setup Control Of Condenser Fans

    Choice of control strategy P-band: The fan capacity is regulated via P-band control. The P band is configured as "Proportional band Xp" PI-Control: The fan capacity is regulated by the PI controller. Continues AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 64 OFF: Monitoring is cut out. FDD sensitivity Set the sensitivity of error-detection on the condenser’s air flow. Must only be changed by trained staff. Air flow tuning value Actual tuning values for air flow. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 65: Setup Control Of High Pressure

    Warning If the regulation is stopped dur- ing high-pressure regulation, the pressure will rise. The system must be dimen- sioned to the higher pressure; otherwise, there will be a loss of charge. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 66: Setup Control Of Receiver Pressure

    IT controller. IT comp. Sgc min. The temperature limit for operation with IT compressor. Will not start when a lower value is detected, regardless of the opening degree of the Vrec valve. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 67: Setup Control Of Heat Recovery

    - Max heat reclaim. Here the controller must receive a volt- age signal, but the regulation is increased to also control the pump, fans and gas cooler bypass. Press the +-button to go on to the next page AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 68 Pump stop limit: Signal in % at which the pump is stopped again Pump start limit: Signal in % at which the pump is started HP CONTROL Pgc HR min: Basic reference for the pressure when exter- nal voltage signal is received. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 69 V3gc bypass start limit: Signal in % at which the gas cooler is disconnected. Flowswitch delay: Duration of stable signal before the new status is used in the regulation. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 70: Setup Display

    Cond. control sensor Pc bar-absolute Pgc bar-absolute Prec bar-absolute Stw8 Shr8 Speed Compressor Unit readout Choose whether readings are to be in SI units (°C and bar) or (US-units °F and psi) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 71: Setup Functions For General Purpose

    5 thermostats temperature control in the compressor room and one alarm 5 pressostats 5 voltage signal function for monitoring the liquid 10 alarm signals level in the receiver. 3 PI-regulations AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 72: Separate Thermostats

    Indicate alarm text for low alarm Separate pressostats 3 - Pressostats 1. Select pressostats Settings as the thermostats In our example, separate pressostat functions are not used. 2. Select actual pressostat 3. Define the required pressostat functions Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 73: Separate Voltage Signals

    Adjust for each input We have subsequently selected a • Name name for the alarm function and • Delay time for DI alarm (common value for all) for the alarm text. • Alarm text AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 74: Separate Pi Functions

    • Max. control output: Maximum permitted output signal • Start up time: Time at startup at which the output signal is force-controlled • Startup output: The output signal size at the startup time. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 75: Configuration Of Inputs And Outputs

    DI 1 Alarm input as a fault if the signal is interrupted. DI 2-10 ... PI-1 Di ref External DI PI-1 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 76 Voltage input 1 - 5 • 0 -5 V, • 0 -10 V, • 1 – 5 V, • 2 – 10 V PI-in temp PI-ref temp PI- in voltage PI-in pres. PI-ref pres. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 77: Set Alarm Priorities

    Se also alarm text page 136. Press the +-button to go on to the next page In our example we select the settings shown here in the display 4. Set alarm priorities for condenser AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 78 Press the +-button to go on to the next page 5. Set alarm priorities for thermostat and extra digital signals In our example we select the settings shown here in the display Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 79: Lock Configuration

    The controller will now make a comparison of selected func- tions and define inputs and outputs. The result can be seen in the next section where the setup is controlled. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 80: Check Configuration

    The problem is corrected by setting module number to 0 and point number to 0. Remember that the setup must be unlocked be- fore you can change module and point numbers. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 81 Press the +-button to go on to the next page The setup of the analog inputs appears as it is supposed to according to 6. Check configuration of Analog Inputs the wiring made. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 82: Check Of Connections

    Check that the value of the alarm for the safety monitoring of compres- sor 1 changes to ON. The remaining digital inputs are checked in the same way. Press the +-button to go on to the next page Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 83 • The sensor has not been connected. • The sensor is short-circuited. 7. Check Analog inputs • The point or module number has not been set up correctly. • The configuration is not locked. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 84: Check Of Settings

    – the ones that can only be seen via the ”Scroll bar”. The last page contains safety limits and restart times. 4. Safety limits 5. Go back to the overview 6. Select condenser group Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 85 10. Go back to the overview and Move on to the press- sostat group Check the settings. 11. Go back to the overview and on to the general alarm inputs Check the settings. 12. The controller setup has been completed. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 86: Schedule Function

    3. Setup schedule Press a weekday and set the time for the day period. Continue with the other days. A complete weekly sequence is shown in the display. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 87: Installation In Network

    The wiring has not been carried out correctly. The termination has not been carried out correctly. The data communication requirements are described in the document: ”Data communication connections to ADAP-KOOL® Refrigeration Con- trols” RC8AC. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 88: First Start Of Control

    Please note that active plant alarms are automatically cancelled when the main switch is in pos. OFF. If active alarms appear when the control is started the reason for these should be found and remedied. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 89: Start The Control

    The controller will now start controlling the compressors and the fans. Note: Control does not start until both the internal and external switch are “ON”. Any external compressor stop breaker must be ON for the compressors to start. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 90: Manual Capacity Control

    See Regulating functions.) Press the blue field against Control mode Select MAN. 4. Set capacity in percent Press in the blue field against Manual capacity. Set the capacity to the required percentage. Press OK. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 91: Regulating Functions

    5. Regulating functions This section describes how the different functions work AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 92: Suction Group

    On cascade systems the signal from Pctrl can be used by both the high-pressure and low-pressure controls either for the controlling sensor or high-pressure monitoring. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 93: Reference

    (10 V) and at min. signal. Limitation of reference To safeguard yourself against a too high or too low regulation reference, a limitation of the reference must be set. P0 ref Max. Min. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 94: Capacity Control Of Compressors

    The Integrator is looking at the deviation between the set point and the current pressure only and increases/reduces the requested capacity correspondingly. The amplification factor Kp on the other hand only looks at the temporary pressure changes. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 95 PI controller is operating – this includes the extension of the zones. The dynamic expansion of the neutral zone is not used when one of the compressors in the group is speed-regulated. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 96: Capacity Distribution Methods

    - The middle column shows (as a percentage) to what extent the individual compressor has been activated within the last 24 hours. - The right column shows the compressor's current operating time. The value should be reset when the compressor is replaced. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 97: Power Pack Types - Compressor Combinations

    *4) When two speed-regulated compressors are used, they must have the same frequency range. For cyclical coupling patterns, the two speed-regulated compressors should be the same size and the subsequent one-step compressors should also be the same size. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 98 The capacity step will now be cut in and the required capacity determined by the controller. The start speed always ought to be set so high that a fast lubrication of the compressor is obtained during the start. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 99 8) The speed controlled compressor will increase speed until the total capacity reaches 60 kw at max speed 9) When reducing capacity the one step compressors will be cut out when the speed on C1 is at minimum speed. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 100 The following one-step compressors will be cut in and out in parallel. The following one-step compressors will be cut in and in accordance with First-In-First-Out principle in order to equalise out in accordance with the selected coupling pattern. operating hours. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 101: Compressor Timers

    100% capacity. It is not normally necessary to limit this max. capacity. Refrigeration No refrigeration The PWM signal must be obtained from a solid state output. The compressor motor and unloaders must be connected to the relay outputs as shown. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 102: Load Shedding

    Alarm: When a load shedding digital inlet is activated, an alarm will be activated to inform that the normal control has been bypassed. This alarm can however be suppressed if so desired. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 103: Cascade Systems - Coordination And Injection

    LT compressors.) Sequence MT comp. request MT comp MT comp release LT comp. T1: The load on the LT circuit requires that compressor capacity be connected. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 104 (Make the connections between the two controllers, so that the controllers are kept galvanically separate). The LT controller is adjusted for LT coordination The MT controller is set for MT coordination release before start. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 105: Injection On

    The reason why the forced closure signal via the network is cancelled before the first compressor starts, is that it will take some time to distribute the signal to all appliance controllers via the network. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 106: Liquid Injection In Suction Line

    The pulse width modulating signal for the AKV valve shall be taken from one of the controller's four solid state outputs. Time delay A time delay can be set which ensures that the injection is delayed during start up. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 107 An alarm limit can be set which will become effective when the suction pressure becomes too high. An alarm will be transmitted when the set time delay has been passed. The regulation continues unchanged. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 108: Oil Management

    This function divides the pulse count by two. The compressor will then stop, after which the remaining pulses will be made. Both high and low pressure and common oil receiver (+ oil separator) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 109 There is one reset and this applies to all com- pressors. Upon reset, all the counters are reset. It can also be reconnected via the service tool indicated in the “Safety monitoring” picture. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 110: Condenser

    Cap. Ctrl sensor = Pc / S7 / Sgc If the regulation sensor is selected for media temperature S7, then Pc is still used as the safety function for high condenser pressure Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 111 When the temperature in the tank has reached the set value, the heat recovery is cut-out again. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 112: Capacity Distribution

    If additional capacity is required, the next fan cuts in at the same time as the first fan switches to minimum speed. From here, the first fan can increase speed again, etc. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 113: Condenser Couplings

    This is accomplished by tuning the function when the condenser is clean. The tuning must not be started until the plant has been run in and runs under normal operation conditions. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 114: Co 2 Transcritical System And Heat Recovery

    Remember the isolation amplifier If signals are received from different controls, e.g. heat recovery for one of the inputs, a galvanically insulated module should be inserted. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 115: Circuit For Heat Recovery Or Hot Tap Water

    • Stw8 and Stw8a. Here regulation is done using the two tempera- ture sensors in the receiver. Stw8 is placed at the top and Stw8a further down. Reference Band AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 116: Circuit For Recovery For Heating

    The pump can be controlled on/off or variably. For Shr4 or DeltaT regulation it must be controlled variably. During variable opera- tion the pump will stop when the regulation desires a lower capacity than the selected min. speed capacity for the pump. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 117 The pump can be controlled on/off or variably. For Shr4 or DeltaT regulation it must be variably controlled. During variable opera- tion the pump will stop when the regulation request a lower capacity than the selected min. speed capacity for the pump. . AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 118 Pgc HR min. and Pg HR offset. c. Fan control The fan’s capacity is tuned down so the temperature is increased. The temperature is measured with Sgc. If necessary, the temperature reference will not be increased Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 119: Circuits For Control Of Co2 Gas Pressure

    Regulation will now follow the set reference curve, but will never go above the set permitted max. pressure for the gas cooler. The current reference can be read from the controller's overview screen. Subcooling Subcooling can be used in the subcritical range. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 120 • From ON at 0%: Here the reference is changed to "Pgc HR Min." • To ON at 100%: Here the reference will increase further using the setting "Pgc HR offset". • Between 0 and 100% the reference is variable. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...

  • Page 121: Receiver Control

    Stop of compressors If the compressors are stopped via the function "External com- pressor stop", the reference for the receiver control will be to the setting "Max. receiver pressure". AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 122: Parallel Compression

    0-10 V signal that indicates the desired capacity. IT comp. release IT comp. running output input (IT comp. release) (IT comp. running) IT comp. release IT comp. running input output (IT comp. release) (IT comp. running) Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 123 The reference for the receiver pres- sure is set in relative bar. Signal from MT Signal to MT (The “IT comp. state” read-out is the signal received from the IT control- ler.) AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 124: General Monitoring Functions

    Alarm limits can be set for low and high pressure, respectively, including separate alarm delays. The individual pressure control function can be adapted to the relevant application as it is possible to give the pressure control a name and indicate alarm texts. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 125 - Adjust Kp until the process starts fluctuating and is constantly fluctuating - Adjust Kp to half the value - Adjust Tn down until the process starts fluctuating again - Adjust Tn to double values AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 126: Miscellaneous

    • “High’ – Alarm relay is activated only with alarms with high priority • “Low - High’ – Alarm relay is activated only with alarms with “low” priority, “medium” or “high” priority. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 127 State a password whether these are correctly attached. c) Select user level d) Select units – either US (e.g. °F and PSI) or Danfoss SI (°C and Note: There is no monitoring when the outlets are overridden. Bar) e) Select language...
  • Page 128 0 = Configuration open 1 = Configuration locked Main switch 0: Controller stopped 1: Regulating Set point suction pressure Setting of required suction pressure reference in °C Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 129 Stepper Motor Valves Please be aware, that this value hat to be set in a RMS value. Some When selecting a Danfoss stepper motor valve, all settings are fac- valve manufacturers are using peak current! tory set. Here, it is only necessary to select the type of valve.

  • Page 130: Appendix A - Compressor Combinations And Coupling Patterns

    - The capacity controlled compressor is the first to start and the last to stop. - Unloader valves are used to close capacity holes - There is operating time equalizing between the compressors 2 and 3 (same size in example). Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 131 The speed-regulated compressor is always the first to start and the last to stop. One-step compressors should be cut in and cut out in accordance with the First-In-First-out principle in order to equalise operating hours. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 132 (90 Hz), the smallest one-step compressor is cut out (C2) and the big one-step compressor (C3) is cut in. - When the speed-regulated compressor again reaches max speed (90 Hz), the smallest one-step compressor (C2) is cut in again. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 133 For more information on the general handling of the speed-regu- lated compressors, refer to section "Power pack types". Cyclical operation - example Here the speed-regulated compressors are the same size The one-step compressors should also be the same size. AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 134 (50 Hz), corresponding to the cut out capacity Example 2: In this example, the speed-regulated compressors are of different sizes and the following one-step compressors are also of different sizes. Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 135 AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 136: Appendix B - Alarm Texts

    Oil level is too low in receiver Recv. High pressure alarm Pressure too high in receiver Rec. high pressure Medium Recv. Low pressure alarm Pressure too low in receiver Rec. low pressure Medium Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 137 The output in question has been put in manual control mode via the AK-ST 500 service tool software Man control ..The output in question has been put in manual control mode via the AK-ST 500 service tool software AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...

  • Page 138: Appendix C - Recommended Connection - Ak-Pc 781

    Oil lvl. Oil lvl. Oil lvl. Oil Low Oil Hi Oil valve AK-XM 205A comp. 1 comp. 2 comp. 3 comp. 4 Separ. 1 Separ. 1 Modul 6 - Saux 1 AK-XM 205A Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 139 Oil lvl. Oil lvl. input 1 Valve C1 Valve C2 Valve C3 Valve C4 Safety C1 Safety C2 Safety C3 Safety C4 GasCool. Receiver Oil valve GasCool. Thermost. Alarm Prec Separat.1 V3gc AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 140 Main Sw. 2 vsd comp. Controller 2 single Modul 2 - Comp. 1 Comp. 2 Comp. 3 Comp. 4 VSD. 1 VSD. 2 4 fan AK-XM 102B safety safety safety safety safety safety Capacity controller RS8GG602 © Danfoss 2015-03 AK-PC 781...
  • Page 141 Comp. 1 Comp. 2 Alarm Fan 1 Fan 2 Fan 3 Fan 4 Comp. speed Comp. 1 Comp. 2 Comp. 3 Comp. 4 Fan 1 Fan 2 Fan 3 Fan 4 Comp. speed AK-PC 781 Capacity controller RS8GG602 © Danfoss 2015-03...
  • Page 142 Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alternations can be made without subsequential changes being necessary in specifications already agreed.

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