GEA Grasso User manual

_551511_om_kas_gbr_1_.doc 1
CO /NH
2 3 Cascade unit
250 - 1000 kW
Operating Instructions

OPERATING INSTRUCTIONS
CO2/NH3CASCADE UNIT
250 - 1000 KW
2 _551511_om_kas_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
CO2/NH3CASCADE UNIT
250 - 1000 KW
_551511_om_kas_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
CO2/NH3CASCADE UNIT
250 - 1000 KW
_551511_om_kas_gbr_1_.doc 5
TABLE OF CONTENTS
1Operating instructions.......................................................................................................................... 10
1.1 Delivery.................................................................................................................................... 10
1.2 Transport and storage ............................................................................................................ 10
1.3 Transport instructions ............................................................................................................. 10
1.4 Installation............................................................................................................................... 10
1.5 Assembly.................................................................................................................................. 11
1.6 Start-up instructions............................................................................................................... 11
1.6.1 Basics ........................................................................................................................... 11
1.6.2 First commissioning..................................................................................................... 11
1.6.2.1 Leak test....................................................................................................... 11
1.6.2.2 Drying, vacuum ............................................................................................ 12
1.6.2.3 Oil charge..................................................................................................... 12
1.6.2.4 Checking the direction of rotation of the driving motor ........................... 15
1.6.2.5 Checking the direction of rotation of the oil pump motor........................ 15
1.6.2.6 Adjustment of oil pressure .......................................................................... 15
1.6.2.7 Mounting the coupling................................................................................ 16
1.6.2.8 Refrigerant charging.................................................................................... 16
1.6.2.9 Operating position of valves ....................................................................... 17
1.6.2.10 Checking the water circuits ....................................................................... 19
1.6.2.11 Initial startup.............................................................................................. 19
1.6.2.12 Setting the setpoint / limit values and safety devices .............................. 20
1.6.2.13 Switching on the CO2refrigerant pumps.................................................. 20
1.6.2.14 Switching on the compressor .................................................................... 20
1.6.2.15 Checking the adjustment of the control slide........................................... 20
1.6.2.16 Checking the control slide adjustment times............................................ 20
1.6.2.17 Automatic mode........................................................................................ 21
1.7 Shutdown in the event of dangerous situations.................................................................... 21
1.8 Switching off ........................................................................................................................... 21
1.8.1 Normal shutdown ....................................................................................................... 22
1.8.2 Shutting down for a lengthy period .......................................................................... 22
1.8.3 Measures during stoppages ....................................................................................... 22
1.8.3.1 Monthly........................................................................................................ 22
1.8.3.2 Four weeks before putting back into service ............................................. 22
1.8.4 Putting back into service after approx 1 year............................................................ 22
2Start-up / Operation of GSC ................................................................................................................ 23
2.1 General Information ............................................................................................................... 23
2.2 Description of the Grasso System Control.............................................................................. 23
2.2.1 View............................................................................................................................. 23
2.2.2 Lamps/ Push buttons .................................................................................................. 23
2.2.3 Operator terminal....................................................................................................... 24
2.2.3.1 Key assignment............................................................................................ 24
2.2.3.2 Open table of contents ............................................................................... 26
2.2.4 Status messages .......................................................................................................... 27
2.3 System description GSC........................................................................................................... 29
2.3.1 Explanation of the system LED................................................................................... 30
2.4 Alarms ..................................................................................................................................... 31
2.4.1 View active alarms and warnings............................................................................... 31
2.4.2 No alarm signal and the compressor will not start.................................................... 31
2.4.3 Restart following Alarms ............................................................................................ 31
3Description of Design and Function .................................................................................................... 34
3.1 Brief Description...................................................................................................................... 34

OPERATING INSTRUCTIONS
CO2/NH3CASCADE UNIT
250 - 1000 KW
6 _551511_om_kas_gbr_1_.doc
3.1.1 Use ...............................................................................................................................34
3.1.2 Design ..........................................................................................................................34
3.2 Refrigerant circuit ....................................................................................................................35
3.2.1 CO2low temperature stage.........................................................................................35
3.2.2 NH3high temperature stage .......................................................................................36
3.3 Oil return system......................................................................................................................36
3.3.1 CO2circuit oil return system ........................................................................................36
3.3.2 NH3circuit oil return system........................................................................................36
3.4 Auxiliary refrigeration unit for CO2separator ........................................................................36
3.5 Safety devices...........................................................................................................................37
3.5.1 CO2circuit ....................................................................................................................37
3.5.2 NH3circuit ....................................................................................................................38
3.6 Monitoring devices ..................................................................................................................38
3.6.1 CO2circuit ....................................................................................................................39
3.6.2 NH3circuit ....................................................................................................................39
4Maintenance Instruction.......................................................................................................................40
4.1 General Information ................................................................................................................40
4.2 Servicing/maintenance and safety ..........................................................................................41
4.3 Searching for leaks on refrigerant side / leak test .................................................................41
4.4 Vacuating, charging and draining refrigerant and oil............................................................42
4.4.1 Evacuating the refrigerant (see also initial start-up) ..................................................42
4.4.2 Charging with refrigerant (see also initial startup; initial charge with refrigerant)..42
4.4.3 Charging characteristics...............................................................................................43
4.4.4 Draining the refrigerant ..............................................................................................43
4.4.4.1 General notes on draining refrigerant.........................................................43
4.4.4.2 Charging refrigerant.....................................................................................43
4.4.4.3 Connections for draining refrigerant...........................................................44
4.4.5 Venting the refrigerant circuits...................................................................................44
4.5 Charging and draining oil (see also putting into service).......................................................44
4.5.1 General notes on handling refrigerator oil.................................................................44
4.5.2 Check oil level ..............................................................................................................44
4.5.3 Oil filling.......................................................................................................................44
4.5.4 Draining, changing, checking oil .................................................................................44
4.5.5 Used oil ........................................................................................................................45
4.6 Maintenance Work ..................................................................................................................45
4.6.1 General notes...............................................................................................................45
4.6.2 Opening the compressor (see also compressor maintenance instructions)...............45
4.6.3 Dismantling the compressor suction filter (see the compressor maintenance
instructions) .............................................................................................................................46
4.6.4 Replacing the suction filter..........................................................................................46
4.6.5 Changing the suction filter before refrigerant pump - CO2circuit.............................46
4.6.6 Oil change....................................................................................................................46
4.6.6.1 Meaning........................................................................................................46
4.6.6.2 Maintenance Work.......................................................................................47
4.6.6.3 Changing the oil ...........................................................................................47
4.6.7 Replace oil filter ...........................................................................................................47
4.6.8 Changing the filter driers - CO2circuit ........................................................................48
4.6.9 Clutch maintenance.....................................................................................................48
4.6.10 Oil pump maintenance(for external oil pump)......................................................48
4.6.11 Checking the pull-in torques at fastener of fixing base ...........................................48
4.6.12 Changing the oil fine separation cartridges .............................................................48
4.6.13 Finding and fixing leaks.............................................................................................49
4.6.14 Cleaning the heat exchangers (heat-carrier / cooling agent sides) .........................49

OPERATING INSTRUCTIONS
CO2/NH3CASCADE UNIT
250 - 1000 KW
_551511_om_kas_gbr_1_.doc 7
4.6.14.1 Chemical cleaning ...................................................................................... 49
4.6.14.2 Mechanical cleaning .................................................................................. 49
4.7 Steps to be followed before starting the system after major repairs ................................... 50
4.7.1 Repair information...................................................................................................... 50
4.7.2 Pressure test, leak test ................................................................................................ 50
4.7.3 Vacuum Test................................................................................................................ 50
4.8 Repair work............................................................................................................................. 50
4.9 Guide to disturbances, their causes and remedies................................................................. 51

OPERATING INSTRUCTIONS
CO2/NH3CASCADE UNIT
250 - 1000 KW
_551511_om_kas_gbr_1_.doc 9
TABLE OF FIGURES
fig. 1: Vacuum required to remove moisture from refrigerating plants .................................................... 12
fig. 2: Motor direction of rotation............................................................................................................... 15
fig. 3: Stop valve opened ............................................................................................................................. 17
fig. 4: Stop valve closed................................................................................................................................ 17
fig. 5: Check valve......................................................................................................................................... 17
fig. 6: Combined stop/ check valve.............................................................................................................. 17
fig. 7: Control valve ...................................................................................................................................... 17
fig. 8: Combined stop/ check valve with integrated control function........................................................ 17
fig. 9: Solenoid valve .................................................................................................................................... 18
fig. 10: Change-over valve............................................................................................................................ 18
fig. 11: oil pressure regulating valve............................................................................................................ 18
fig. 12: Overflow valve, safety valve ............................................................................................................ 18
fig. 13: Pressure controlled check valve ....................................................................................................... 18
fig. 14: Quick acting valve, spring-held........................................................................................................ 18
fig. 15: Charging valve, draining valve......................................................................................................... 18
fig. 16: Service valve ..................................................................................................................................... 18
fig. 17: Oil temperature limiter .................................................................................................................... 19
fig. 18: Temperatur controlled valve ........................................................................................................... 19
fig. 19: Thermostatic expansion valve.......................................................................................................... 19
fig. 20: Solenoid valve plate with throttle screws ....................................................................................... 20
fig. 21: Exterior view GSC............................................................................................................................. 23
fig. 22: GSC operator terminal ..................................................................................................................... 24
fig. 23: "Status messages" display................................................................................................................. 28
fig. 24: Restart following Alarms ................................................................................................................. 32
fig. 25: Diagram of the main components of the CO2/NH3cascade, Part 1............................................... 34
fig. 26: Diagram of the main components of the CO2/NH3cascade, Part 2............................................... 35
fig. 27: Oil fine separation cartridge............................................................................................................ 49

OPERATING INSTRUCTIONS
CO2/NH3CASCADE UNIT
250 - 1000 KW
10 _551511_om_kas_gbr_1_.doc
At the same time, check the nitrogen filling and
recharge to the specified overpressure of 0.3 bar ...
0.5 bar, if required. Dry nitrogen with a residual
moisture of ≤300 ppm is used for this purpose.
1 OPERATING INSTRUCTIONS
1.1 Delivery
CO /NH
2 3-cascade units are delivered with an inert
gas charge (nitrogen) in the refrigerant circuit. The
heat exchanger connections are closed. Check on
arrival for possible transport damage and report
damage in writing.
Warning!
Cascades are to be adequately protected
from external influences during transport
and storage.
This usually concerns lengthy standing
times outdoors before installation and
putting into service of the refrigeration
plant.
Protect cascades from damage, dirt and moisture
during longer periods of storage prior to
setup/installation.
(check inert gas charge) Grasso recommends the use of plastic
sheeting to cover the whole product.
The compressors of the cascade unit are not charged
with oil, therefore the cascade must not be started
unless properly installed and commissioned. The venting slots of the electric motors
must always be covered!
Dispatch is effected in the type of packing stipulated
in the order. The cascade unit is generally supplied
without packing. 1.3 Transport instructions
Use the four carrier eyes on the base frame as
slinging points for crane transport.
1.2 Transport and storage
Cascades are high-quality products which must be
handled with due care. Protect the equipment from
impacts and put it down carefully.
To prevent damage on piping and components
attach crossbeams to the ropes.
Hint!
When transported by crane, the cascade must have
the same position as in operation. Do not use
attaching points other than those provided for this
purpose.
Pushing and pulling on components or
climbing on the cascade unit or pipes
easily causes damage and should be
avoided at all costs.
All the information needed to manipulate the
cascade is indicated in the "Transport Instructions".
After completion of erection on the foundation, and
prior to starting up the cascade remove the
transport safety devices installed in the works.
Warning!
It is prohibited to sling cascade units to
any fittings or piping or at the eye
screws/carrying ears on compressor,
electric motor or switch cabinet.
The cascade unit should only be stored in closed, dry
rooms if possible. Storage in the open air under a
roof is only permissible for short periods.
Take special care not to attach the ropes near to
small diameter tubing or to damage the same. Use
spacers if necessary.
1.4 Installation
Select the installation site with care so that any
possibly leaking substances do not penetrate the
ground or enter the surface or ground water (Water
Supply Law WHG).
Position the cascade on the transport vehicle such
that it is prevented from sliding and tilting. The
competent staff member or the company is
responsible for ensuring transport safety. The cascade units have to be installed in closed
machine rooms and on a level surface. Provide
enough space for maintenance work.
The storage area of cascades shall be roofed, plain
and paved and secured against access of
unauthorized persons. The cascade must be
protected against knocks and impacts.
Rigid installation
The frame of the cascade unit is placed on
foundation bolts on a prepared foundation.
Turn the shaft of the compressor at least every four
weeks (approx. 1/8 revolutions). The frame must be levelled with suitable shims such
that the coarse alignment (radial and angular