Danfoss ADAP-KOOL AK-PC 783 Design Manual
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Danfoss ADAP-KOOL AK-PC 783 Design Manual

Capacity controller with cascade control, refrigeration control systems
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Design Guide
Capacity controller with
cascade control
AK-PC 783
ADAP-KOOL® Refrigeration control systems

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Summary of Contents for Danfoss ADAP-KOOL AK-PC 783

  • Page 1 Design Guide Capacity controller with cascade control AK-PC 783 ADAP-KOOL® Refrigeration control systems...

  • Page 2: Table Of Contents

    Set control of suction group LT ..........61 Miscellaneous ..................116 Set control of cascade heat exchanger ........64 Appendix A – Compressor combinations and coupling pat- Set oil management ...............65 terns ......................120 Appendix B - Alarm texts ..............126 Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 5 S4, Ss, Sd, condenser pressure, condenser pressure in temperature, S7 media temperature etc. A graphical display with control buttons can also be fitted. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 13 42 - 43 - 44 Solenoid valve 18 (DO7) 45 - 46 - 47 19 (DO8) 48 - 49 - 50 Option Board Please see the signal on the page with the module. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 23 13 (DO 5) 37 - 36 - 39 Alarm Light 14 (DO6) 40 - 41 - 42 Solenoid valve 15 (DO7) 43 - 44 - 45 16 (DO8) 46 - 47 - 48 AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 24: Extension Module Ak-Xm 208C

    • Voltage supply to the module • Communication active with the bottom PC board (red = error) • Status of outputs AO1 to AO4 Output: 24 V d.c. = 500 m A / coil max. 20-500 step/s Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

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

    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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 31 AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 32: Preface To Design

    Alarm function The requirements to the installation are described in a separate If the alarm is to be sent to a signal transmitter, a relay output will document. have to be used. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 34: Design Of A Compressor And Condenser Control

    Min. On-time Speed regulation Liquid injection in suction line Step and speed regulation Liquid injection in cascade heat exchanger Speed regulation first step Liquid injection in screw compressor External start/stop of compressors Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 35: Connections

    Must always be used in connection with compressor regulation. nothing else is mounted in the pressure pipe). • Sd (discharge gas temperature) • Shrec Must always be used in connection with compressor regulation. Temperature sensor for heat recovery AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 36 The result is that the following modules should be used: • AK-PC 783 controller • AK-XM 204A input and output module • AK-XM 208C stepper output module • AK-XM 102B digital input module • AK-XM 103A analog input and output module Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 39: Determine The Connection Points

    2 (AO 2) 29 - 30 - 31 - 32 3 (AO 3) 33 - 34 - 35 - 36 4 (AO 4) 37 - 38 - 39 - 40 Continued next page AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 40: Connection Diagram

    GND connection to a sensor signal must be made on the same module receiving the temperature signal. You may then yourself write the module number in the circle and draw the individual connections. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 41 Example continued: AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 43: Ordering

    Real time clock with battery backup. To be mounted in an AK controller 080Z0252 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 44 Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 45: Mounting And Wiring

    • AK-PC 783 controller module • AK-XM 204A 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-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 48: Wiring

    25 - 26 - 27 - 28 ETS 2 (AO 2) 29 - 30 - 31 - 32 3 (AO 3) 33 - 34 - 35 - 36 4 (AO 4) 37 - 38 - 39 - 40 Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 MT-compres- sors, 2 LT-compressors and cascade heat exchangers. The example is shown two pages in. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 53 The main switch will stop all regulations. In the event of temperature increases, • Monitoring of low and high level in oil receiver there is a risk of loss of filling. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 54: Authorization

    You will access the login display by pressing the icon at the top left corner of the display. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 57: Set Plant Type

    I'm alive relay A relay will "release" if the regulation is stop- ped. Night select via DI Change to night-time operation at the signal for a DI input. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 58: Set Control Of Suction Group Mt

    Minimum speed for start of Variable speed drive (Must be set higher than “VSD Min. Speed Hz”) VSD max speed (40.0 – 120.0 Hz) Highest permissible speed for the compressor motor Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 59 Pc Max limit Maximum value for the condenser pressure in °C 3 K below the limit, the entire condenser capacity will be cutin and the compressor capacity reduced. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 60 Max liquid injection OD Set the maximum degree of opening of the valve as a %. Max discharge Maximum Sd temperature in the event of any individual Sd readings. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 61: Set Control Of Suction Group Lt

    3. Set values for the reference Press the +-button to go on to the next page. 4. Set values for capacity control Press the +-button to go on to the next page. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 62 6. Set values for main step and any unloaders Press the +-button to go on to the next page. 7. Set values for safe operation Press the +-button to go on to the next page. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 63 9. Set operation time for compres- Press the +-button to go on to the next page. 10. Set times for safety cutouts Press the +-button to go on to the next page. 11. Set Misc. functions AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 64: Set Control Of Cascade Heat Exchanger

    MOP-temperature for MT circuit. Tc-LT min Minimum temperature for Tc in LT circuit Tc-LT max Maximum temperature for Tc in LT circuit Advanced settings Choose whether the technical control settings are to be visible. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 65: Set Oil Management

    (Oil equalisation may be defined extension module.) using “Select plant type... ” but only Danfoss recommends this function to avoid any compres- for cyclical compressor operation.) sor damages due to lack of care. (In order to keep things simple, this function is not used as an example.)
  • Page 66 ("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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 67: 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 68 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 69: Setup Control Of Pump Function

    Configure in Kelvin per minute. Heat recovery cutout Temperature value where the thermostat cuts-out the heat recovery. Heat recovery cutin Temperature value where the thermostat cuts-out the heat recovery. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 70: Setup Display

    Choose whether readings are to be in SI units (°C and bar) or (US-units °F and psi) In our example, separate displays are not used. The setting is included here for information. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 71: Setup Functions For General Purpose

    3 voltage signal 10 alarm signals 3 PI-regulations 3. Define number of required functions We have not used the general purpose functions in our example. The images are included for guidance only. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 72: Separate Thermostats

    Settings as the thermostats Separate pressostats 1. Select pressostats 3 - 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 73: Separate Voltage Signals

    It is included for Set the number of digital alarm inputs guidance only. Adjust for each input • Name • Delay time for DI alarm (common value for all) • Alarm text AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 75: Configuration Of Inputs And Outputs

    Open has been selected here for all the safety circuits. This means that the controller will receive signal under normal operation and register it External DI PI-1 as a fault if the signal is interrupted. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 77: Set Alarm Priorities

    Se also alarm text page 124. 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 80: Check Configuration

    0 and point number to 0. Remember that the setup must be unlocked be- fore you can change module and point numbers. Press the +-button to go on to the next page Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 81 Press the +-button to go on to the next page 6. Check configuration of Analog Inputs The setup of the analog inputs appears as it is supposed to according to the wiring made. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 83 • The point or module number has not been set up correctly. • The configuration is not locked. Press the +-button to go on to the next page 7. Check Analog inputs AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 84: Check Of Settings

    – the ones that can only be seen via the ”Scroll bar”. 4. Safety limits The last page contains safety limits and restart times. 5. Go back to the overview 6. Select condenser group Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 86: Schedule Function

    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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 91: Regulating Functions

    5. Regulating functions This section describes how the different functions work AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 92: Suction Group

    LT provides condenser heat to the brine. When the controlling sensor is selected as S4, P0 is used as a safety function for low suction pressure and will ensure disconnection of compressor capacity (frost protection). Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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. Reference Max. Min. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 95 NZ. In the controller the readout “Actual band” will show in which zone the PI controller is operating – this includes the extension of the zones. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 96: Capacity Distribution Methods

    - At the different stops the compressor with the highest number of operating hours will be stopped first. - For compressors with several steps, the operating time equalizing is carried out between the compressors’ main steps. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 102: Cascade Control

    Depending on the plant/design type, the injection can be defined in the following ways: - Always ON. Follows the main switch on the controller. - Follows the LT circuit - Follows a remote signal on a DI input. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 103: 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. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 104: 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 105 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 106: Oil Management

    - Advanced stop. (allows pulses when the compressor is stopped) This function divides the pulse count by two. The compressor will One oil separator per then stop, after which the remaining pulses will be made. compressor and common oil receiver Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 107 The function only come into force when all compressors are in operation. Set an interval time at which the compressors are alter- nately paused for a given period of time here, so that oil equalisa- tion can be performed. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 108: Pumpe Styring

    Cycle". On changeover to the second pump, the first one will remain in operation for the "PumpDel" time. It will then stop. At stop before start "PumpDel" will be the break time for changeo- ver. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 109 Pump alarms can also be suppressed by setting pump selection to the "faulty" pump - if the flow switch is OK, the alarm will be acknowledged/suppressed as a result. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 110: Condenser

    Cap. Ctrl sensor = Pc / S7 If the control sensor is selected for media temperature S7, then Pc is still used as the safety function for high condenser pressure and Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 111 In both cases it applies that when the heat recovery function is de-activated, the reference for the condensing temperature will then decline slowly in accordance with the set rate in Kelvin/ minute. AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 114: 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 115 - 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 116: Miscellaneous

    Unexpected disconnection of the compressor, condensation fan or frequency convertor can result in unexpected temperature increases in the system. If necessary, use the necessary safety signals to ensure that the controller receives signals about discon- nections. Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 117 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 118 Readout of the total P0 Reference in LT circuit Setting of Setpoint for P0 in LT circuit Actual media temperature measured with S4 Superheat in suction line MT circuit Sc3 out door temperature in °C Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 119 The current applied to each phase of the stepper motor during actual valve movement. This value is limited to 7 bits and a range When selecting a Danfoss stepper motor valve, all settings are fac- of 0 – 1000 mA given in 10ma steps. Verify the range against the tory set.

  • Page 120: 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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 121 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 122 (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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 123 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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 124 (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 RS8GN202 © Danfoss 11-2013 AK-PC 783...
  • Page 125 AK-PC 783 Capacity controller RS8GN202 © Danfoss 11-2013...

  • Page 126: Appendix B - Alarm Texts

    Temperature signal for S7 media temperature sensor is defective Detect blocked air flow Medium Air flow reduced cond. A The intelligent air flow monitoring of the condenser reports that a cleaning is due Capacity controller RS8GN202 © Danfoss 11-2013 AK-PC 783...

  • Page 127: Ak-Pc

    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 783 Capacity controller RS8GN202 © Danfoss 11-2013...
  • Page 128 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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