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GEA Grasso Manual

GEA Grasso Manual

System control standard package with piston compressors single stage and two stage
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Grasso
Refrigeration Division
GRASSO SYSTEM CONTROL
Standard Package with Piston Compressors
Single Stage and Two Stage
Manual
2003/0
638660_um_gsc_gbr

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Summary of Contents for GEA Grasso

  • Page 1 Grasso Refrigeration Division GRASSO SYSTEM CONTROL Standard Package with Piston Compressors Single Stage and Two Stage Manual 2003/0 638660_um_gsc_gbr...
  • Page 2  Copyright Grasso GmbH Refrigeration Technology The contents of this documentation and the enclosed drawings, sketches and diagrams are intended only for plant users and operating personnel. They may be neither duplicated nor divulged to third parties or firms without written consent.
  • Page 3 GRASSO SYSTEM CONTROL Grasso Refrigeration Division OREWORD ESCRIPTION OF RASSO YSTEM ONTROL ONTROL EQUENCE NITIAL TART YSTEM ESCRIPTION ECHNICAL LARMS ROUBLESHOOTING ERVICE PPENDICES 01.2003/ 0 638660E_contents.doc - 1/1...
  • Page 5 Refrigeration Division FOREWORD Introduction Grasso has been producing refrigerating compressors and compressor units for a wide range of different applications for several decades. A new compressor control has been developed for universal use based on our many years’ operational experience.
  • Page 6 GRASSO SYSTEM CONTROL Grasso Refrigeration Division suction side stop valve economiser discharge side stop valve oil separator coupling piston compressor terminal box drive motor Figure 0.1: View of piston compressor unit, type Grasso6210 with economiser Foreword - 2 638660E_foreword.doc 01.2003/ 0...
  • Page 7 GRASSO SYSTEM CONTROL Grasso Refrigeration Division General P & ID This diagram is intended to give a general overview of the measuring points provided. The supplied unit may deviate from this diagram. MAIN SWITCHGEAR CABINET MAIN SWITCHGEAR CABINET Input signals...

  • Page 11: Table Of Contents

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division DESCRIPTION OF THE GRASSO SYSTEM CONTROL Grasso System Control - General 1.1.1 View 1.1.2 Lamps/ Push buttons Operator terminal 1.2.1 Key assignment 1.2.2 Menu structure 1.2.2.1 Password level 1.2.2.2 General image format 1.2.3 Call up table of contents 1.2.3.1...

  • Page 13: Description Of The Grasso System Control

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division DESCRIPTION OF THE GRASSO SYSTEM CONTROL Grasso System Control - General The GSC consists of the control unit with operator keypad and display unit, indicator lights for “Running“, “Warning“ and “Alarm“, emergency stop button, output relays etc.

  • Page 14: Lamps/ Push Buttons

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.1.2 Lamps/ Push buttons White indicator light (Running) This indicator lamp flashes slowly when the compressor unit is in the “Ready“ state. This lamp flashes quickly during start up of the compressor. Once the compressor has started, the light becomes steady.

  • Page 15: Key Assignment

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.1 Key assignment Function Change to the next display window F2, F3 Go to the menu item described in the text display directly above Switch on the compressor unit, start enabled Start 1 compressor (Press key for 5 sec. in operation mode “Manual”).

  • Page 16: Menu Structure

    Each password level has a different number allocated to it. The passwords for Levels 1 to 8 can be freely allocated by the user. The password for the highest password level 9 is specified by Grasso on delivery and cannot be subsequently changed.

  • Page 17: General Image Format

    Level 1 Password level 8 Service level Changes in the configuration menu possible — in addition to level 2 Password level 9 Grasso only Changes in the system menu possible — in addition to level 8 1.2.2.2 General image format The image format is identical in all the images.

  • Page 18: Call Up Table Of Contents

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.3 Call up table of contents To get to the table of contents, press the key. A list of the available menus is then displayed. Number Title Help text Actual values Display of all unit’s actual values...
  • Page 19 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Suction temp Suction temp: Suction temperature in °C Disch temp Disch temp: Discharge temperature in °C Oil temp Oil temp: Oil temperature in °C << Actual values 01 >> Suct dif temp Suct dif temp:...

  • Page 20: Control Settings Menu

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division Unloaded start Unloaded start: Remaining time for unloaded start in secs Motor feedback Motor feedback: Remaining time for motor running feedback signal from Auto start dly compressor drive motor starter << Actual values 01 >>...

  • Page 21: Operating Mode Menu

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.3.3 Operating mode menu 15 Operating modes Manual + Manual Switchover operating modes Manual Start/Stop Select the operating mode using Manual +/- Operating mode >> Confirm selection with Example shown is operating mode type 01 — Manual stop start and manual capacity control (Please refer to section 2.1)
  • Page 22 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Suction press Suction press: Actual suction pressure in bar (a) Psuc hi alarm Psuc hi alarm: Actual alarm limit for maximum suction pressure in bar (a) High warning High warning: Enter the warning value as an offset to the <<...
  • Page 23 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Disch temp Disch temp.: Actual discharge temperature in °C Tdis hi alarm Tdis hi alarm: Alarm limit for maximum discharge temperature in °C High warning High warning: Enter the warning value as an offset to the alarm value <<...
  • Page 24 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Imot hi alarm Imot hi alarm: Alarm limit for maximum current in A High limit High limit: Begin of the motor current limitation - Decr factor enter value as an offset to the alarm value in A <<...

  • Page 25: Alarm Menu

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.3.5 Alarm menu 25 Alarms Alarms View: The alarm number, date, time and status of the alarmare displayed. Status ‘K’ is logged when the alarm first occurs, View Print ‘Q’ when the alarm is acknowledged and ‘G’ when the >>...

  • Page 26: Unit Options Menu

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.3.7 Unit options menu 35 Unit Options Unit options Act value: Jump to display of sequence control values Sequence control Parameter: Jump to sequence control parameters Values Parameter >> Unit options Act value: Jump to display of economiser values.
  • Page 27 GRASSO SYSTEM CONTROL Grasso Refrigeration Division ECO system ECO system: Select the type of economiser (No, A, B, C, D or 2xB) Inject control Inject control: Select “GSC” if electronic injection mounted, otherwise “No” AKVA type AKVA type: Select AKVA type mounted (No, 10-1 through 20-5) <<...
  • Page 28 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Sensor: Sensor: Select the sensor type e.g. “suction pressure”, “discharge Begin (4mA) pressure”, etc. End (20mA) Begin (4mA): Start of measuring range of the sensor selected, e.g. 0 bar << Configuration 01 >> End (20mA): End of measuring range of the sensor selected, e.g.

  • Page 29: System Main Menu

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division 1.2.3.9 System Main Menu 90 System Main Menu System main menu Events: Further submenus: “View”, “Print”, “Number”, “Delete”, “Overflow”, “Text” Events Alarms Alarms: Further submenus: “View”, “Print”, “Number”, “Delete”, >> “Overflow”, “Text” System main menu Screens: Further submenus: “Edit”, “Print”...

  • Page 30: Status Display

    GRASSO SYSTEM CONTROL Grasso Refrigeration Division Status display To get to the status display, press the key several times, or press the key and then This display shows all of the information shown in the first actual values screen plus the status of the compressor unit.
  • Page 31 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Limit disch temp 01 A capacity limitation is active (discharge temperature too high), the capacity cannot be decreased. In case the discharge temperature rises, the capacity will be increased. A capacity limitation is active (motor current too high), Limit mot current 01 the capacity cannot be increased.
  • Page 35 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2. Control sequence Overview of the operating modes Explanation of symbols and characters used General starting conditions 2.3.1 Start to start timer (anti- recycle timer) 2.3.2 Stop to start timer Start up sequence 2.4.1 Single stage and booster piston compressor packages 2.4.2...
  • Page 36 GRASSO SYSTEM CONTROL Grasso Refrigeration Division MENU 15 „OPERATION MODES“ Control via GSC buttons Compressor blocked Service manual Stop/Start control Manual + Manual manual +/-- Capacity control manual Stop/Start control Manual + Auto auto +/-- Capacity control auto Stop/Start control...
  • Page 37 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2. CONTROL SEQUENCE Overview of the operating modes Operation modes Signal for… Name Explanation Start/Stop Capacity +/- Service Compressor motor blocked Manual + Manual Manual control via OP Manual Manual Manual Start/Stop via OP and full...
  • Page 38 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Operation modes Signal for… Name Explanation Start/Stop Capacity +/- Start/stop via network (MPI or Profibus- DP) from a remote Master controller. Network set Remote + Net-Net.SP The capacity control is based on a Network...
  • Page 39 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.3.1 Start to start timer (anti- recycle timer) As electric motors are particularly highly loaded during the start up process, it is important to comply with the manufacturer’s requirements regarding the allowed number of starts per hour.
  • Page 40 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Start up sequence 2.4.1 Single stage and booster piston compressor packages Starting conditions fulfilled Output — compressor motor on Feedback — compressor motor on equals 1 ’Motor feedback’ timer active Unloaded start Release of capacity control system Booster pressure reached Figure 2.4,...
  • Page 41 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.4.2 Two stage piston compressor packages Starting conditions fulfilled Output — compressor motor on Feedback — compressor motor on equals 1 ’Motor feedback’ timer active Unloaded start Release of capacity control system Release of start up with ’Pull down’...
  • Page 42 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Switch off sequence 2.5.1 Switching off sequence in the normal case for booster, single- and two stage compressor packages Stop command Output — compressor motor on Decrease of capacity Minimum capacity reached Figure 2.6, Switching off sequence in the normal case (booster, single- and two stage) •...
  • Page 43 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.5.3 Switching off sequence in the normal case and in case of an alarm with ’Pump down’ Stop command Output — compressor motor on Decrease of capacity Minimum capacity reached ’Pump down’ timer active...
  • Page 44 Compressor control 2.6.1 Capacity control All piston compressor units from Grasso are equipped with a variable capacity control system in the geometric range 0 — 100 %. An external temperature or the suction pressure can be selected as the controlled variable.
  • Page 45 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Proportional zone If the process value lies within this zone the step time is calculated based on the difference between process value and set point. The zone lies symmetric around the set point. The input range is 2.0 through 50.0 K. Furthermore, this value must always be greater than the value for the neutral zone.
  • Page 46 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Safety control (Alarms, warnings and limitations) The following situations are taken into account for activating the alarm output signal: • Oil system alarms • Minimum / maximum limits reached • Compressor motor’s start equipment alarms •...
  • Page 47 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.1 Oil system monitor of piston compressor packages The oil system monitor is responsible for monitoring the functionality of the oil system. The package is switched off if alarms occur. The difference between the oil pressure and the crankcase pressure is monitored. In case no crankcase pressure is measured, the suction pressure is used in stead.
  • Page 48 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.1.2 Switching sequence in case of too low oil differential pressure alarm during running Output — compressor motor on ’Oil dif press’ OK ’Oil dif run’ timer active ’Low oil differential pressure’ alarm Figure 2.14, Oil system monitor in case of too low oil differential pressure alarm during running •...
  • Page 49 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2 Compressor motor alarms 2.7.2.1 ’Motor feedback’ alarm — start up of compressor motor takes too long Output — compressor motor on ’Motor feedback’ signal equals 1 ’Motor feedback’ timer active ’Time before motor feedback too long’...
  • Page 50 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.3 Motor current limitation The motor current limitation prevents overloading of the compressor drive motor. It does not become effective until the start up process has been completed. If the calculated motor current for the next capacity step reaches the initial limitation value (e.g. 105% of the full load current), the compressor capacity cannot be increased any further.
  • Page 51 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Imot hi alarm Imot hi alarm: Alarm limit for maximum current in A High limit High limit: Begin of the motor current limitation - Decr factor enter value as an offset to the alarm limit in A <<...
  • Page 52 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.5 Low suction pressure limitation The suction pressure limitation attempts to prevent a low suction pressure alarm. If the suction pressure reaches the initial limitation value, the compressor capacity cannot be increased any further. If the suction pressure reaches the decrease limit, the compressor capacity is reduced by 1 capacity step immediately.
  • Page 53 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.6 Low and high suction pressure alarm Both low and high suction pressures are monitored. In case the suction pressure becomes too low or too high an alarm is generated. Both alarms do not become active until the start up process has been completed. After starting the compressor motor an additional delay time of 5 minutes becomes active for the high suction pressure alarm only.
  • Page 54 GRASSO SYSTEM CONTROL Grasso Refrigeration Division The high suction pressure alarm function is illustrated in the following diagram. Suction pressure Time characteristic of the suction pressure Warning limit Al.. Alarm limit ML W.. Warning active ML A.. Alarm active Reset of the active alarm Figure 2.22, High suction pressure alarm...
  • Page 55 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.7 Low external temperature limitation (Chiller outlet temperature) This limitation is only active if an external temperature sensor is installed. If the external temperature reaches its initial limitation value, the capacity of the compressor cannot be increased any further.
  • Page 56 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.8 Low external temperature alarm (Chiller outlet temperature) In case of Chiller application this alarm is used as frost protection of the evaporator. The low external temperature alarm function is illustrated in the following diagram.
  • Page 57 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.9 High discharge pressure limitation The discharge pressure limitation is intended to prevent a high discharge pressure alarm. If the discharge pressure reaches its initial limitation value, the compressor capacity cannot be increased any further.
  • Page 58 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.10 High discharge pressure alarm The high discharge pressure alarm function is illustrated in the following diagram. Discharge pressure Time characteristic of the discharge pressure Forced reduction of the capacity due too high discharge pressure...
  • Page 59 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.11 High intermediate pressure alarm The intermediate pressure is monitored. In case the pressure becomes too high, an alarm is generated. The alarm does not become active until the start up process has been completed and the additional delay time of 5 minutes has expired.
  • Page 60 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.12 Low oil differential pressure alarm The oil differential pressure is monitored. In case the pressure becomes too low, an alarm is generated. The alarm does not become active until the start up process has been completed and two separate delay times have expired.
  • Page 61 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.13 Low suction gas overheat alarm The suction gas overheat is monitored. In case this overheat becomes too low, an alarm is generated. This alarm does not become active until the start up process of the compressor has been completed and an additional delay time has expired.
  • Page 62 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.14 Low intermediate gas overheat alarm The intermediate gas overheat is monitored. In case this overheat becomes too low, an alarm is generated. This alarm does not become active until the start up process of the compressor has been completed and an additional delay time has expired.
  • Page 63 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.15 High discharge temperature limitation The discharge temperature limitation is intended to prevent a high discharge temperature alarm. If the discharge temperature reaches its initial limitation value, the compressor capacity cannot be decreased any further.
  • Page 64 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.16 High discharge temperature alarm The same alarm is applied for the intermediate temperature at the low pressure side of a two stage compressor. This temperature is also called intermediate temperature LP (T The discharge temperature alarm function is illustrated in the following diagram.
  • Page 65 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.17 Start limitation based on too low oil temperature The start limitation is intended to prevent the compressor from starting if too much refrigerant is dissolved in the oil. If the calculated oil temperature limit reaches the saturation value based on the oil pressure in the compressor crankcase, the compressor is blocked.
  • Page 66 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.18 Low and high oil temperature alarm Both low and high oil temperature are monitored. In case the oil temperature becomes too low an alarm is generated, because the viscosity becomes too high at low oil temperatures and good lubrication cannot be ensured.
  • Page 67 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.2.19 Low and high compressor motor speed alarm (for frequency control only) Both low and high compressor motor speed are monitored. If the motor speed becomes too low or too high an alarm is generated. The low compressor motor speed alarm does not become active until the start up process has been completed.
  • Page 68 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.3 Specific control of two stage piston compressors In case of two stage piston compressors 4 intermediate cooling systems (ECO system) are available, system A, system B, system C and system D. Refrigeration injection controlled by the GSC is possible for the systems A and B only.
  • Page 69 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 2.7.3.2 Monitoring of the intermediate pressure, intermediate temperature and discharge temperature The GSC monitors the intermediate pressure, intermediate temperature at the low pressure side (T ) and the ) of the two stage compressor. The monitoring function uses the ϕ value. This ϕ value...
  • Page 70 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Via this procedure of monitoring the ϕ value and adapting the capacity steps the intermediate pressure and both discharge temperatures (T and T ) are kept within the valid operating conditions of the selected compressor type.
  • Page 71 GRASSO SYSTEM CONTROL Grasso Refrigeration Division For a constant discharge pressure (T ) the suction pressure (T ) moves along the line ’a — e’ from the right to the left. Not before the suction pressure reaches point ’a’ (ϕ = 1.0) the compressor is allowed to work as a two stage compressor.
  • Page 72 Only Grasso experts are allowed to change the ECO value, because changes have a large influence on the amount of refrigerant that is injected in the ECO system. Normally, the ECO value has a range of 0.700 through 1.500.
  • Page 75 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Initial Start UP Overview of steps to take for commissioning Selection of the components installed and sensor scaling Adjusting control settings Adjusting operating mode settings Adjusting limit values Adjusting time values Parameterise unit options Saving changes Check the compressor unit’s wiring...
  • Page 77 GRASSO SYSTEM CONTROL Grasso Refrigeration Division INITIAL START UP This chapter describes the most important steps to be taken before commisioning the GSC. These steps can also be usefull in case changes are being made in the system. Overview of steps to take for commissioning Press “ACK”...
  • Page 78 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Selection of the components installed and sensor scaling Press Select the main menu 50 “Configuration“. Confirm each selection or input with Press once (page on to the next image). The following selection appears on the display:...
  • Page 79 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Line: “ECO system“, use the keys to select whether an economiser system is installed (two stage only). Line: “Injection control", use the keys to select whether the GSC controls the refrigerant injection in case of an economiser.
  • Page 80 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Press once. The following selection appears on the display: Suction temp Oil temp Oil separat << Configuration 01 >> Line: “Suction temp“, use the keys to select whether the suction temperature sensor is fitted.
  • Page 81 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Press once. The following selection appears on the display: Configuration accept save ( ?) ( ?) << Use the key “accept“ to accept the new configuration. To undo all changes and exit the configuration menu without accepting and saving press After changing the compressor type and/or refrigerant and accepting the new configuration with “accept”...
  • Page 82 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Adjusting limit values Press Select the main menu 20 “Limit values“. The following selection appears on the display: Suction press Psuc low alarm Low warning Limit values 01 >> Page on using the key.
  • Page 83 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Saving changes Press Select the main menu 50 “Configuration“. Press until the following selection appears on the display: Configuration accept save ( ok) ( ?) << Use the key “save” to permanently save the configuration on the EPROM of the PLC.
  • Page 87 GRASSO SYSTEM CONTROL Grasso Refrigeration Division SYSTEM DESCRIPTION GSC Explanation of the system LED C7-CPU Selection of the operating mode Meaning of the key-operated switches Installation of the memory card (EPROM) 4.4.1 Description of the memory card used 4.4.2 Installation of the Siemens SIMATIC C7 memory card...
  • Page 89 GRASSO SYSTEM CONTROL Grasso Refrigeration Division SYSTEM DESCRIPTION GSC The system LEDs are located on the front of the GSC. These system LEDs provide information about the status of the controller. Explanation of the system LED The position of the system LED is given in Chapter 1.2, Fig.1.3.
  • Page 90 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display elements for Profibus SF-DP BUSF Meaning Remedy (red) (green) Bus error (physical defect) Check the bus cable for a short circuit or breakage DP interface error for various baud Analyse diagnosis, if necessary, replan the...
  • Page 91 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Meaning of the key-operated switches SF-DP Meaning Remedy (red) RUNP The C7 CPU processes the application program. (R-P) The program and data can: - be read out of the C7-CPU with the PG (C7 - be transferred into the C7-CPU or be amended there (PG The C7 CPU processes the application program.
  • Page 92 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Installation of the memory card (EPROM) 4.4.1 Description of the memory card used The PLC Siemens C7-633/P uses the following standard memory card: Memory card Capacity Technical data Daten Ansicht 6ES7 951-0KG00-0AA0 128 kB 5V Flash 128 kByte / 8 bit Figure 4.2: Memory card...
  • Page 93 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Step Procedure Use the “key” in order to reset the memory The next step is to reset the PLC memory, so that the new program will be uploaded from the memory card. In order to reset the memory, the PLC operation mode key state must be changed from “R”...
  • Page 94 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Adjusting the date/ time The current date and time can be adjusted at the OP, e.g. to correct for summer/winter time. Any change made affects all the messages and images, in which a date/ time variable appears. The display format for the date and time is specified in the project planning and cannot be changed at the OP.
  • Page 97 GRASSO SYSTEM CONTROL Grasso Refrigeration Division TECHNICAL DATA Types of sensors used Terminal connection diagram Customer’s input signals 5.2.2 Customer’s output signals Extended data communication (interfaces) 5.3.1 Explanation of the MPI 5.3.2 Explanation of the Profibus Description of the periphery modules 5.4.1...
  • Page 99 GRASSO SYSTEM CONTROL Grasso Refrigeration Division TECHNICAL DATA This technical data refers to the whole GSC control cabinet. Operating voltage 100 to 240 V AC Mains frequency 47 to 63 Hz Power consumption Maximum 300 W Control voltage 24V DC...
  • Page 100 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Terminal connection diagram 5.2.1 Customer’s input signals 294M ext. setpoint (4-20 mA) ext. temperature (4-20 mA) P2.2 2nd setpoint aktiv ext. acknowledgement ext. start release ext. capacity decrease ext. capacity increase ext. unit on...
  • Page 101 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 5.2.2 Customer’s output signals 16PE emergency stop Release condenser Release refr. pump auxilairy output Main alarm Motor runs Ready for central operation Motor on voltage (max 250 V, 6A) 01.2003/0 638660E_chapter5.doc Kap.5 - 3...
  • Page 102 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Extended data communication (interfaces) The GSC is equipped with an MPI interface as a standard. This interface can be used to connect up to 32 users to each other. As this interface is an internal Siemens interface with multi-point capability, it can only be used between Siemens controls (S7).
  • Page 103 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Power supply and authorisation input Programming interface for OP Figure 5.2: Interfaces C7-633, power supply and Author. connection The individual users can also be fitted with a bus cable connector. This connector is inserted directly in the bus interface (9-pin sub-D jack).
  • Page 104 The slave address for the two slaves is set independent of each other with DIP switches that are located on the top side of the device. The DP 1 address is for Grasso usage only. The default setting for the DP1 address is 21 (see figure 5.4).
  • Page 105 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Description of the periphery modules The periphery modules are the link between the GSC, the compressor unit, the power panel and the customer. 5.4.1 Periphery bus coupler As link between the PLC and periphery modules a periphery bus coupler is used (see figure 5.5). The address selector must be set to address 11 (1 x1 + 1 x10).
  • Page 106 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 5.4.3 Digital output terminals As digital output terminals several types of terminals are used for the piston compressor control. Reason is the usage of different kind of voltages for the solenoid valves (240 V AC or 115 V AC) and other signals (24 V DC).
  • Page 107 GRASSO SYSTEM CONTROL Grasso Refrigeration Division The KL2134 digital output terminal connects the binary control signals from the automation unit on to the actuators at the process level with electrical isolation. The terminal is protected against reverse polarity connection. The terminal contains four channels that indicate their signal state by means of light emitting diodes.
  • Page 108 GRASSO SYSTEM CONTROL Grasso Refrigeration Division The KL3202 and KL3204 analog input terminals allow resistance sensors to be connected directly. The Bus Terminal‘s circuitry can operate the sensors using 2-wire connection techniques. Linearisation over the full temperature range is realised with the aid of a microprocessor. The temperature range can be selected freely.
  • Page 111 GRASSO SYSTEM CONTROL Grasso Refrigeration Division ALARMS General 6.1.1 Alarms 6.1.2 Warnings 6.1.3 View active alarms and warnings Possible text displays for alarms and warnings 6.2.1 General 6.2.2 List of all alarms and warnings Description and diagnosis of alarm messages...
  • Page 113 GRASSO SYSTEM CONTROL Grasso Refrigeration Division ALARMS General Shut down on alarms are carried out to prevent the refrigeration equipment operating outside of design limits and do not represent a defect in the controls. The alarm signals are divided into 2 groups:...
  • Page 114 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Possible text displays for alarms and warnings 6.2.1 General The GSC produces all the alarms and warnings listed in the following section. All the warnings and alarms are stored in a history file for possible later analysis by the operator.
  • Page 115 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Alarm histogram Full Alarm text number Alarm Refrigerant data not found. Please select other refr. Warning Low external temperature Warning PLC power supply interrupted Warning Replace PLC battery Warning PLC operation mode changed Warning Selection not permitted.
  • Page 116 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Alarm histogram Full Alarm text number Alarm (01) Motor current too high Alarm (01) Wire failure motor current Alarm (01) Motor speed too low Alarm (01) Motor speed too high Alarm (01) Wire failure motor speed...
  • Page 117 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Alarm histogram Full Alarm text number Alarm (01) Liquid in compressor Discharge temperature (HP) too low Alarm (01) Compressor heating Discharge temperature (HP) too high Alarm (01) Pump down time elapsed. Stop pressure not reached...
  • Page 118 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Description and diagnosis of alarm messages Display message / Explanation Possible cause of the alarm Alarm clearance The level in the refrigerant Reduce the level in the refrigerant 004 Alarm separator is too high.
  • Page 119 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The external temperature is too Remove cause of low external 025 Alarm low. temperature in the refrigeration plant. ‘Text low alarm’ limit is set too Change ‘Text low alarm’...
  • Page 120 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The oil differential pressure is too Remove cause of low oil differential 050 Alarm (01) low. pressure at the compressor. ‘dPoil low alarm’ limit is set too Change ‘dPoil low alarm’...
  • Page 121 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The suction gas overheat is too Remove cause of low suction gas 055 Alarm (01) low. overheat in the refrigeration plant. ‘Suct dif temp’ limit is set too high.
  • Page 122 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The discharge pressure is too high. Remove cause of high discharge 060 Alarm (01) pressure in the refrigeration plant. Discharge ‘Pdis hi alarm’ limit is set too low.
  • Page 123 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The motor current is too high. Remove cause of high motor current in 065 Alarm (01) the refrigeration plant. ‘Imot hi alarm’ limit is set too low.
  • Page 124 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The emergency stop button has Reset the emergency stop button. 070 Alarm (01) been pressed. The high pressure switch on the Reset the discharge pressure switsch.
  • Page 125 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The terminal connections have Check the terminal connections for 075 Alarm (01) become loose or a wire is broken. tightness and continuity of wiring.
  • Page 126 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The terminal connections have Check the terminal connections for 080 Alarm (01) become loose or a wire is broken. tightness and continuity of wiring.
  • Page 127 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance The feedback contactor is defective Replace the feedback contactor. 091 Alarm (01) — open contact. Motor feedback Power failure due to tripped fuse.
  • Page 128 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Display message / Explanation Possible cause of the alarm Alarm clearance ‘Pump down time’ too short. Increase the ‘Pump down time’ in the 096 Alarm (01) time values menu to a suitable value. Pump down time ‘Stop pressure’...
  • Page 129 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Warning message Possible cause Warning clearance The selection or entered data is not 044 Warning permitted in combination with Selection not other selections and/or data. permitted. Please Certain selections and/or data check input data.
  • Page 130 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Warning message Possible cause Warning clearance The intermediate gas overheat is Remove the cause of low 100 Warning (01) too low. intermediate gas overheat in the refrigeration plant. Low intermediate ’Intm dif temp’ plus ’Low warning’...
  • Page 131 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Warning message Possible cause Warning clearance Suction pressure is too low. Remove the cause for low suction 105 Warning (01) pressure in the refrigerating plant. ‘Psuc low alarm’ plus ‘Low warning’ Change ‘Psuc low alarm‘ and ‘Low Low suction set too high.
  • Page 132 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Warning message Possible cause Warning clearance The suction temperature is too low. Remove the cause for low suction 112 Warning (01) temperature in the refrigerating plant. Low suction The sensor has not been correctly Enter the correct calibration value.
  • Page 133 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Warning message Possible cause Warning clearance The discharge temperature at the Remove cause of high discharge 127 Warning (01) high pressure side is too high. temperature in the refrigeration Compressor heating plant. Discharge temperature...
  • Page 137 GRASSO SYSTEM CONTROL Grasso Refrigeration Division ACKNOWLEDGING AND RESETTING ALARMS AND WARNINGS Information about the status of the controls in case of an alarm/warning Restart following Alarms Information from the controls in case of a system error 7.3.1 7.3.2 Profibus DP/DP-coupler 7.3.3...
  • Page 139 GRASSO SYSTEM CONTROL Grasso Refrigeration Division ACKNOWLEDGING AND RESETTING ALARMS AND WARNINGS Information about the status of the controls in case of an alarm/warning The occurrence of an alarm/warning is signalled by: At the control cabinet: Signal lamp (red) ‘Alarm’/ signal lamp (yellow) ‘Warning’.
  • Page 140 GRASSO SYSTEM CONTROL Grasso Refrigeration Division By pressing the cursor key ‘down’ or the key ‘up’, you can now view the still active alarms or warnings (scroll). If only warning signals are still active, the compressor can be restarted, otherwise the cause for the still active alarm messages have to be corrected before the compressor can be restarted.
  • Page 141 GRASSO SYSTEM CONTROL Grasso Refrigeration Division After pressing the ‘ACK’ key, the alarm is acknowledged at the PLC. The alarm message is deleted in the display. The main menu appears in the display. Possibility 1 Possibility 2 (red) ON (red) OFF...
  • Page 142 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Information from the controls in case of a system error 7.3.1 A system error is triggered by the Siemens system software, e.g. by the detection of an SPS hardware fault. A system error is signalled by the “SE” LED.
  • Page 143 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Option 2: The “SE“ LED is alight and the “STOP“ LED flashes slowly (1Hz); the “RUN“ LED is off. The application program is not running. The compressor is switched off and the ‘alarm’ relay signals an alarm (relay has de-energised).
  • Page 144 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Option 4: The ‘SE’, ‘RUN’ and ‘BATF’ LEDs are alight. The “alarm signal“ LED is flashing. The application program continues to run; the compressor is not switched off. A warning message appears in the display.
  • Page 145 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 7.3.2 Profibus DP/DP-coupler Figure 1: Profibus DP/DP-coupler The LEDs on the front side of the DP/DP coupler have the following meaning: 24 Volt Error Meaning (green) (red) (green) (green) No 24V supply voltage 24V supply is applied and is OK Device is running;...
  • Page 146 GRASSO SYSTEM CONTROL Grasso Refrigeration Division 7.3.3 Periphery bus coupler After switsching on, the bus coupler immediately checks the connected configuration. During this „self test“ all functions of the connected terminals and the communication with the in- and output modules are tested. Error free start-up is signalled by extinction of the red LED „I/O ERR“.
  • Page 149 Damage report The Grasso System Control is a high quality product. Nevertheless, damage or malfunctions during operation cannot be completely avoided. Please direct any questions concerning malfunctions that occur to your Grasso supplier. Your contact in Germany: Grasso GmbH Refrigeration Technology Holzhauser Straße 165...
  • Page 150 DAMAGE REPORT Grasso GRASSO GMBH REFRIGERATION TECHNOLOGY Refrigeration Division SERVICE Address of the owner/operator: Type and model number of the product: Designation of the defective module Suspected cause of the damage: Date damage occurred: Operating hours of the module until damage occurred:...
  • Page 151 GRASSO SYSTEM CONTROL Grasso Refrigeration Division • List of parameters (see chapter 9) Special operation for Service personal To enable service personal to solve problems quickly, the GSC is equipped with extra functionality like: Service function Operation Explanation Freeze display with all operating parameters just before appearance of „Freeze display“...
  • Page 152 DAMAGE REPORT Grasso GRASSO GMBH REFRIGERATION TECHNOLOGY Refrigeration Division SERVICE Suction press Suction press: Suction pressure in bar (a) Interm press Interm press: Intermediate pressure in bar (a) Disch press Disch press: Discharge pressure in bar (a) << Freeze Displ. 01 >>...
  • Page 153 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Digitale outputs 0.7 — 0.0: Status of the digital outputs 0.0 through 0.7 (0.0 at the 0.7 — 0.0 right hand side) SET: Status of the digital outputs 0.0 through 0.7 (0.0 at the <<...
  • Page 157 GRASSO SYSTEM CONTROL Grasso Refrigeration Division LIST OF PARAMETERS Title Unit HotKey Actual values K 06 ACTUAL values of compressor unit data + remaining times for timers Control settings K 14 Parameters for control values Range Default setting Project setting Set Point 1 °C...
  • Page 158 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Limit values Parameters for limiting values Range Default setting Project setting Suct dif temp dTo low alarm 0,0 … 25,0 Low warning 0,0 … 10,0 Interm press Pint hi alm n1 bar (a) 3,0 …...
  • Page 159 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Limit values Parameters for limiting values Range Default setting Project setting External temp Text low alarm °C -65,0 ... +65,0 Low warning 0,0 ... 10,0 Low limit 0,0 ... 10,0 Decr limit 0,0 ...
  • Page 160 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Configuration Parameters for configuration values _______________________ ____ . ____ . ____ MPI ____ / ____ ____ . ____ . ____ ____ ____ -- ____ . ____ . ____ Default setting Project setting...
  • Page 161 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Configuration Parameters for configuration values Range Default setting Project setting Sensor scaling: Discharge pressure Sensor: Disch press Begin (4mA) bar (a) 0,0 ... 40,0 End (20mA) bar (a) 0,0 ... 40,0...
  • Page 162 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Configuration Parameters for configuration values Range Default setting Project setting Sensor scaling: Intermediate temperature Sensor: Intm temp HP Offset (K) °C -10,0 ... 10,0 Spann (%) °C -20,0 ... 20,0 Sensor scaling:...
  • Page 163 GRASSO SYSTEM CONTROL Grasso Refrigeration Division Title Unit HotKey Configuration Parameters for configuration values Range Default setting Project setting Sensor scaling: External temperature Sensor: External temp Begin (4mA) °C -60,0 ... 140,0 -60,0 End (20mA) °C -60,0 ... 140,0 140,0...
  • Page 165 02/04 Master_Backpage.doc...

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