GEA Grasso User manual

_805011_om_gsc_sp2_gbr_1_.doc 1
Grasso System Control
for two stage Chiller/ Packages with Screw
Compressors
Operating Instructions

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
2 _805011_om_gsc_sp2_gbr_1_.doc
COPYRIGHT
All Rights reserved. No part of this publication may be copied or published by means of printing, photocopying,
microfilm or otherwise without prior written consent of Grasso. This restriction also applies to the corresponding
drawings and diagrams.
LEGAL NOTICE
This publication has been written in good faith. However, Grasso cannot be held responsible, neither for any
errors occurring in this publication nor for their consequences.

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 3
SYMBOLS USED IN THIS MANUAL
Danger!
This is an important warning. Non-observance these warnings can cause accidents with relevant
damages on persons or serious damages on the compressor or refrigerating plant.
Warning!
Attention! Caution! Important!
Hint!
Tip! Note!

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 5
TABLE OF CONTENTS
1Start-up / Operation of GSC .................................................................................................................. 8
1.1 General Information ................................................................................................................. 8
1.2 Description of the Grasso System Control................................................................................ 8
1.2.1 View............................................................................................................................... 8
1.2.2 Lamps/ Push buttons .................................................................................................. 10
1.2.3 Operator terminal....................................................................................................... 11
1.2.3.1 Key assignment............................................................................................ 12
1.2.3.2 Call up table of contents ............................................................................. 14
1.2.4 Status displays ............................................................................................................. 15
1.3 System description GSC........................................................................................................... 18
1.3.1 Explanation of the system LED................................................................................... 18
1.4 Alarms ..................................................................................................................................... 19
1.4.1 View active alarms and warnings............................................................................... 19
1.4.2 No alarm signal and the compressor will not start.................................................... 19
1.4.3 Restart following Alarms ............................................................................................ 20

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 7
TABLE OF FIGURES
fig. 1: View of outside of switchgear cabinet................................................................................................ 8
fig. 2: View of inside of switchgear cabinet .................................................................................................. 9
fig. 3: GSC operator terminal ....................................................................................................................... 11
fig. 4: "Status messages" display................................................................................................................... 15
fig. 5: Restart following Alarms ................................................................................................................... 20

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
8 _805011_om_gsc_sp2_gbr_1_.doc
1 START-UP / OPERATION OF GSC
1.1 General Information
Warning!
Read the ´Operating Instructions´ before starting the screw compressor unit/ chiller.
The ´Operating Instructions´ is an extract from the GSC User Manual, containing the most important
information for the operator.
The indexes are not identical with those of the GSC User Manual. The index [X.X.X.] under the
headings of this operating instruction refers to the matching chapter within the User manual.
For more specific information see GSC User Manual or press the key to obtain more
information about the selected parameter.
The GSC is supplied with text in native language.
1.2 Description of the Grasso System Control
1.2.1 View
[Chapter 1.1.1. in user manual]
fig. 1: View of outside of switchgear cabinet
A HP
B LP
C Warning
D Failure

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 9
fig. 2: View of inside of switchgear cabinet
1 Profibus DP/DP-coppler
2 Bus Terminal
3 Type of Power Supply
4 Emergency stop relay
5 Relays
6 Socket-outlet for service

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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1.2.2 Lamps/ Push buttons
[Chapter 1.1.2. in user manual]
White indicator light (Running HP compressor)
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.
This lamp flashes quickly during the shut down operation, until the compressor drive motor is switched off.
White indicator light (Running LP compressor)
This lamp flashes during start up of the LP-compressor.
This lamp flashes quickly during start up of the compressor.
Once the compressor has started, the light becomes steady.
This lamp flashes quickly during the shut down operation, until the compressor drive motor is switched off.
Yellow indicator light (Warning)
This lamp flashes if an operating condition reaches a preset value (Warning /Pre-alarm).
Detection of this warning can be acknowledged at the operator panel. Warnings are automatically reset after the
cause has gone.
The flashing light changes over to a steady light.
This indicator light switches off again when the operating conditions are back to normal.
Red indicator light (Alarm)
This lamp flashes if an operating condition exceeds its permitted value, the machine shuts down on alarm.
This state is signalled by a red flashing light. After the alarm has been acknowledged at the operator panel, this
flashing light changes over to a steady light, as long as the alarm condition remains.
Once the cause of the alarm has been corrected, this indicator light switches off (after it has been acknowledged).
Emergency Stop button
This red button can be used to switch the compressor unit off at any time in case of an emergency. The operator
terminal controls remain functional.

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 11
1.2.3 Operator terminal
[Chapter 1.2. in user manual]
The operator terminal is the interface between the operator and the control unit.
All switching, operating and control actions are carried out via this operator terminal.
fig. 3: GSC operator terminal
System LED’s
A
B Function keys
C soft keys
D CPU operating mode setting
E digital keybord
F cursor keys
G System keys
System keys LED‘s
H

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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1.2.3.1 Key assignment
[Chapter 1.2.1. in user manual]
Key Function
Go to the menu item described
+
Back to previous display
Move to next display
+
Switch on the compressor unit, start enabled
Start HP-compressor (Press key for 5 sec. in operation mode "Manual")
Increase capacity of HP-compressor (in case of manual capacity control only)
Start LP-compressor (Press key for 5 sec. in operation mode "Manual")
Increase capacity of LP-compressor (in case of manual capacity control only)
without function
+
Call up display of actual values
Call up alarm signals
Lamp test
Switch off the compressor unit, start disabled
Stop HP-compressor (Press key for 5 sec. in operation mode "Manual")
Reduce capacity of HP-compressor (in case of manual capacity control only)
Stop LP-compressor (Press key for 5 sec. in operation mode "Manual")
Reduce capacity of LP-compressor (in case of manual capacity control only)
without function
+
Call up controls –settings
Call up operating mode setting

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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Key Function
Call up the menu overview
Return or cancel input
Acknowledge, reset failure and warning
Confirm input
Press the button once for display of a help text
Switch over to the 2nd keyboard level
Cursor keys
Functions of the F1 ... F4 buttons
These functions are only available if the symbols can be seen in the display.
Back to previous display
Go to the menu item described
Move o next display
Standard functions of the Shift button
Change between the possible selections
+ or
Alter the display contrast
+

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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Special function of the shift key
Change to the Status display
+
Change to the "Language selection + Contrast" menu
+
Change to the "Digital inputs / outputs" display
+
Change to the "Transfer" menu
+
stop with
Change to the "Password" menu
+
Change to the "Date, Time" menu
+
1.2.3.2 Call up table of contents
[Chapter 1.2.3. in user manual]
key. A list of the available menus is then displayed.
To get to the table of contents, press the
Number Title Help text
Display of all unit’s actual values
05 Actual values
10 Control settings Display and set up of all control parameters
15 Mode Selection of operation mode
20 Limit values Set up of alarm, warning and limitation parameters
25 Fault messages Display of current and previous alarms
30 Timer settings Set up of timers
35 Options Selection of unit option menus

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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Number Title Help text
50 Configuration Enter:
—Refrigerants
—SC-Type
—Code
—- with/ without economiser
—- scaling of the sensors
90 Main system menu
To get to these menus, position the cursor on the menu name (using the or key) and confirm with the
key.
Danger!
Parameter changes in menu 20, 30, 35, 50 can cause serious damage to the screw compressor
unitor chiller!
1.2.4 Status displays
[Chapter 1.3. in User Manual]
To get to the "status display" views, 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.
fig. 4: "Status messages" display
AV-LP: Actual value (pressure or temperature) always displayed in °C
SP: Set Point display in °C
Pos LP: Current slide position in %
dPoil: Differential oil pressure in bar
Tc: Condensation temperature in °C
dOilf: Differential oil filter pressure in bar
Hint!
See menu 05 actual values

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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The operating status provides information about the compressor unit.
The following status messages are possible:
Initialisation Initialisation of the control after switching on the power supply or after saving the
settings (RAM →ROM)
Start to start HP A switch on frequency limitation of the HP compressor drive motor is still active
Oil drain A switch on block period is active, the oil pump has run too long by itself
(Minimum position was not reached during start or stop procedure)
Standby Compressor unit/ chiller ready for switching on, but one or more starting conditions
are still not fulfilled e.g. process variable still below set point
No start release The controller is waiting for an external signal to enable the start of the unit
Force to Min HP Starting procedure issued, slide moves to minimum position (HP)
Starting HP Compressor motor has been started, but the switchover to "Delta" has not yet taken
place or the startup has not yet been completed.
Running Compressor motor running in "Delta" or startup has been completed. Package/ Chiller
in operation.
Psuc Limitation A capacity limitation is active (suction pressure too low), "reduce output" solenoid
valve is opened.
Pdis Limitation A capacity limitation is active (discharge pressure too high), "reduce output" solenoid
valve is opened.
Imot Limitation HP A capacity limitation is active (HP motor current too high), "reduce output" solenoid
valve is opened.
Text Limitation A capacity limitation is active (external temperature too low), "reduce output"
solenoid valve is opened.
Toil Limitation Oil temperature too high, "refrigerant injection" is enabled (optional)
Stopping HP The compressor unit/ chiller has received a shutdown command, the capacity slide is
moved towards its minimum position (HP)
Compressor off The compressor has switched off
Stop to start timer Start delay after each stop
Failure A failure has occurred, which is still active.
Pump by itself The minimum position was not reached during switch on or off procedure. The oil
pump continues to try to adjust the control slide in the min direction. After the oil
pump run by itself the oil block period becomes active.
Pull down Pinterm The intermediate pressure is drawn off down to the switch on pressure (release of
the LP compressor)

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
_805011_om_gsc_sp2_gbr_1_.doc 17
A switch on frequency limitation of the LP compressor drive motor is still active
Start to start LP
A capacity limitation is active (LP motor current too high), "reduce output" solenoid
valve is opened.
Imot Limitation LP
A capacity limitation as active (LP discharge pressure too high), "reduce output"
solenoid valve is opened
Pdis Limitation LP
A capacity limitation as active (HP suction pressure too low), "reduce output" solenoid
valve is opened
Psuc Limitation HP
Starting command issued, control slide moves into the minimum position (LP)
Slide to min LP
Compressor motor has been started, and the running feedback signal from the
starter panel has not yet been received (LP)
Starting LP
The compressor unit/ chiller has received a shutdown command, the capacity slide is
moved towards its minimum position (LP)
Stopping LP
Text display flashes
Italic lettering
Text appears as static text
Normal lettering
The overall status of the compressor unit is displayed with the LEDs in and .
Key Colour Status Explanation
Green Flashing
The unit/ chiller has received a start request. The
compressor could start any moment now.
Green Continuous light
The unit/ chiller has received a start request. The
compressor is running.
The unit/ chiller is malfunctioning. The compressor is
not running. The (red) indicator light ‘Collective fault’
flashes or is permanently lit.
None OFF
+
red Continuous light
The unit/ chiller is switched off. The compressor is not
running.
Green Continuous light
Display of the system deviation or the ext. actuating
pulses of the HP compressor (more output is required)
Green Continuous light
Display of the system deviation or the ext. actuating
pulses of the LP compressor (more output is required)
Green Continuous light
Display of the system deviation or the ext. actuating
pulses of the HP compressor (less output is required)
Green Continuous light
Display of the system deviation or the ext. actuating
pulses of the LP compressor (less output is required)

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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1.3 System description GSC
[Chapter 4. in user manual]
The system LEDs are located on the front of the GSC. These system LEDs provide information about the status of
the controller.
1.3.1 Explanation of the system LED
[Chapter 4.1. in User Manual]
The position of the system LED is given in Chapter figure 3, page 11.
Meaning of the status and error displays
Display Meaning Explanation
SF (red) C7-CPU-centralised fault Lights up for:
—Hardware errors,
—Firmware errors,
—Programming errors,
—Parameterising errors,
—Computational errors,
—Time errors,
—Faulty internal memory storage,
—Battery failure or the standby supply is missing while MAINS
ON,
—Peripheral error in the internal peripheral functions.
Further information about the malfunction that has occured can
be read out of the diagnosis memory using the PG.
BATF (red) Battery error Lights up, if battery
—does not have enough voltage,
—is defective,
—is missing.
DC5V (green) Voltage supplyfor C7 lights up, if the internal DC 5V supply is OK.
FRCE (yellow) Force-order lights up, if a Force-order is active.
RUN (green) Operating state RUN of the C7-
CPU
lights up, if the C7 CPU application program is running.
flashes (2Hz) during the C7 CPU start up (the STOP lamps also
lights up; after the STOP lights go off, the outputs are released).
STOP (yellow) Operating state STOP of the C7
CPU
lights up, if the C7 is not processing a CPU-application program.
flashes at 1-second intervals, if C7 CPU general reset (MRES) is
required.
SF-IM (red) Switching module - centralised
fault
lights up, if the connection between C7 and the extension rack
is interrupted.

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
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Display Meaning Explanation
Alarm active lights up, if a malfunction has been confirmed, but is still active.
(red) flashes, if a further malfunction has been activated.
Help (green) Help text available lights up, if a help text is available.
Shift (green) Switch over function active lights up, if the SWITCHOVER function is active.
1.4 Alarms
[Chapter 6. in user manual]
1.4.1 View active alarms and warnings
[Chapter 6.1.3. in user manual]
The ´Status mode´ is displayed by pressing the key several times. The most important actual values are
shown in the first three rows and in the 4th row the status message is shown.
By scrolling with the cursor keys and all active alarms and warnings are displayed.
1.4.2 No alarm signal and the compressor will not start
[Chapter 6.5. in user manual]
Compressor will not start, although there is no active alarm.
Key “ON”has been pressed and the LED K1 ”ON”is flashing.
Cause Remedy
No ‘start release’signal The input ´start release´ is not
closed.
Close input or install a link.
‘Auto Start dly’active The time setting ‘Auto start dly’in
‘control settings menu’has not yet
expired.
Wait until the delay time has
expired.
‘Start to start’delay active The time setting ‘Start to start’in
‘Timer settings’menu has not yet
expired.
Wait until the delay time has
expired.
actual value < (set point + ½ NZ) Check set point and neutral zone
settings in ´Control settings´menu.
NZ = neutral zone
In case of suction pressure control
the set point value is entered in
degrees Celsius.

OPERATING INSTRUCTIONS
GRASSO SYSTEM CONTROL
FOR TWO STAGE CHILLER/ PACKAGES WITH SCREW
COMPRESSORS
20 _805011_om_gsc_sp2_gbr_1_.doc
1.4.3 Restart following Alarms
[Chapter 7.2. in user manual]
fig. 5: Restart following Alarms
Caution!
It is not possible to restart the compressor as long as the cause of the alarm still exists!