Star Cold MC001E Installation, Operation And Maintenance Manual

Star Cold

MC-line

CONDENSING UNITS

INSTALLATION, OPERATION AND MAINTENANCE

BE VERY CAREFUL WHEN YOU MEET THIS INDICATION ON THE LEFT SIDE

INSTALLATION, OPERATION AND MAINTENANCE

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1. GENERAL INFORMATION AND INTRODUCTION.............................................................................4

1.1. SYSTEM TECHNICAL DATASHEET............................................................................................ 4

2. PROCEDURES BY CLIENT ON DELIVERY........................................................................................ 4

2.1. CONDITION CHECK ....................................................................................................................4

2.2. UNLOADING AND HANDLING OPERATIONS ............................................................................ 4

2.2.1 SLINGING AND PRECAUTIONS ............................................................................................................... 4

2.2.2 POSITIONING.............................................................................................................................................. 5

3. LOCATION AND POSITIONING ..........................................................................................................5

3.1. BASE AND POSITIONING ...........................................................................................................5

3.1.1 OUTDOOR UNIT POSITIONING............................................................................................................... 5

3.1.2 ACCESSIBILITY ......................................................................................................................................... 5

3.1.3 CONDENSER COOLING AIR..................................................................................................................... 5

3.1.4 CONDENSER COOLING WATER............................................................................................................. 5

3.1.5 ELECTRICAL POWER SUPPLY LINE ....................................................................................................... 5

3.1.6 EARTHING.................................................................................................................................................. 6

3.2. POSITION OF EVAPORATOR UNITS AND THERMOSTAT BULB.............................................6

4. REFRIGERATION CONNECTIONS REQUIRE QUALIFIED PERSONNEL ........................................ 6

4.1. PIPELINES ...................................................................................................................................6

4.2. COLD PIPELINE INSULATION ....................................................................................................6

4.3. SEALING EFFICIENCY TESTING................................................................................................6

4.4. UNIT SEALING EFFICIENCY TEST............................................................................................. 6

4.5. SYSTEM SEALING EFFICIENCY CHECK ...................................................................................7

5. ELECTRICAL CONNECTIONS AND HOOK-UP ................................................................................. 7

5.1. PRECAUTIONS AND CHECKS.................................................................................................... 7

5.1.1 POWER SUPPLY AND TOLERANCES ..................................................................................................... 7

5.2. ELECTRICAL DRAWING..............................................................................................................7

5.2.1 WIRE DIMENSIONS .................................................................................................................................. 7

5.2.2 ELECTRICAL CONNECTIONS BETWEEN THE CONDENSING UNIT AND AIR EVAPORATORS. ........ 7

5.2.3 REMOTE EVAPORATORS/CONDENSERS – SAFETY SWITCH.............................................................. 7

5.2.4 ELECTRICAL CONNECTIONS BETWEEN THE CONDENSING UNIT AND CONTROL PANEL. ............ 8

5.2.5 POSITION OF THERMOSTAT SENSOR .................................................................................................... 8

5.3. TESTS ..........................................................................................................................................8

5.3.1 PRELIMINARY VISUAL INSPECTIONS ................................................................................................... 8

6. REFRIGERANT CHARGING OPERATIONS REQUIRE QUALIFIED PERSONNEL ..........................8

6.1. REFRIGERANT TYPE AND LUBRICANT OIL .............................................................................8

6.2. VACUUMING THE UNIT........................................................................................................................... 8

6.3. REFRIGERANT CHARGING ..................................................................................................................... 8

7. INSPECTION OF THE CONDENSER FANS REQUIRES QUALIFIED PERSONNEL. ....................... 9

7.1. CHECKING THE DIRECTION OF ROTATION.............................................................................9

7.2. ELIMINATION OF OBSTRUCTIONS TO AIR FLOW....................................................................9

8. CONTROL AND STATUS PANEL ....................................................................................................... 9

8.1. ACCESS PROCEDURE (only on enclosed units for outdoor installation).....................................9

8.2. PROTECTION CALIBRATION AND CHECKS .............................................................................9

8.3. ACCESS RESTRICTION ..............................................................................................................9

8.4. SETTABLE PROTECTIONS......................................................................................................... 9

8.5. FUSE REPLACEMENT...............................................................................................................10

9. AUTOMATIC FUNCTIONALITIES ..................................................................................................... 10

9.1. COLD ROOM TEMPERATURE CONTROL ...............................................................................10

9.2. DEFROST MANAGEMENT ........................................................................................................ 10

9.3. CONDENSATION PRESSURE CONTROL ................................................................................ 10

9.4. MOP ELEMENT IN THERMOSTATIC VALVES .........................................................................10

9.5. PUMP DOWN MODE OPERATION............................................................................................10

9.6. OIL TEMPERATURE CONTROL IN SYSTEMS WITH SCREW COMPRESSORS ...................10

10. PROTECTIONS ..............................................................................................................................10

10.1. PRESSURE OVERLOAD IN COOLING CIRCUIT..................................................................10

10.2. REFRIGERANT PRESSURE DEFECT ..................................................................................11

10.3. INSUFFICIENT COMPRESSOR LUBRICATION....................................................................11

10.4. INSUFFICIENT OIL LEVEL IN COMPRESSOR ..................................................................... 11

10.5. COMPRESSOR MOTOR TEMPERATURE OVERLOAD thermal cutout module...................11

10.6. CONDENSER FAN MOTOR TEMPERATURE OVERLOAD..................................................11

10.7. AIR EVAPORATOR FAN MOTOR TEMPERATURE OVERLOAD .........................................11

10.8. INCORRECT PHASE SEQUENCE.........................................................................................11

11. SIGNALS ........................................................................................................................................12

11.1. LIQUID TRANSFER SIGHT GAUGE ......................................................................................12

11.2. HUMIDITY INDICATOR ..........................................................................................................12

11.3. OIL LEVEL SIGHT GAUGE .................................................................................................... 12

11.4. REFRIGERANT PRESSURE GAUGES .................................................................................12

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12. SYSTEM START-UP IN PRESENCE OF QUALIFIED PERSONNEL............................................12

12.1. PRELIMINARY CHECKS........................................................................................................12

12.1.1 CASING PREHEATING ............................................................................................................................ 12

12.1.2 PRECAUTIONS ........................................................................................................................................ 12

12.1.3 CHECKING THE DIRECTION OF COMPRESSOR ROTATION ............................................................. 13

12.1.4 CHECKING THE DIRECTION OF FAN ROTATION ................................................................................ 13

12.1.5 PANEL CLOSURE CHECK ...................................................................................................................... 13

12.1.6 REFRIGERANT CHARGE CHECK .......................................................................................................... 13

12.1.7 LUBRICANT OIL RETURN CHECK ......................................................................................................... 13

12.1.8 THERMOSTATIC VALVE CALIBRATION CHECK .................................................................................. 13

12.1.9 FILTRATION ON SUCTION ON INITIAL START-UP ............................................................................... 13

13. PRECAUTIONS IN THE EVENT OF PROLONGED DISUSE........................................................14

13.1. CLOSURE OF REFRIGERANT VALVES ...............................................................................14

13.2. RE-START AFTER PROLONGED SHUTDOWNS ................................................................. 14

13.2.1 ADVANCE POWER-UP ............................................................................................................................ 14

13.2.2 CHECKS AND PRECAUTIONS................................................................................................................ 14

14. PERIODIC MAINTENANCE BY QUALIFIED PERSONNEL.......................................................... 14

14.1. PRECAUTIONS ...................................................................................................................... 14

14.2. MONTHLY MAINTENANCE (OR EVERY 200 HOURS).........................................................14

14.2.1 SAFETY DEVICE AND CONTROL CHECK ............................................................................................. 14

14.2.2 ELECTRIC TERMINAL TIGHTENING CHECK ........................................................................................ 14

14.2.3 ELECTRIC CONTACT CONDITION CHECK ...........................................................................................14

14.2.4 REFRIGERANT AND OIL LEAK CHECK .................................................................................................14

14.2.5 CASING HEATER CHECK ....................................................................................................................... 15

14.2.6 EARTHING EFFICIENCY CHECK ........................................................................................................... 15

14.2.7 CONDENSER CLEANING........................................................................................................................ 15

14.2.8 MECHANICAL FILTERS ON INTAKE (when fitted) ................................................................................. 15

14.3. QUARTERLY MAINTENANCE (OR EVERY 800 HOURS) ....................................................15

14.3.1 REFRIGERANT HUMIDITY CHECK ........................................................................................................ 15

14.3.2 DRIER FILTER CARTRIDGE REPLACEMENT ....................................................................................... 15

14.3.3 COMPRESSOR NOISE – VIBRATION CHECK ....................................................................................... 15

15. PROTECTING THE ENVIRONMENT – MAINTENANCE - SCRAPPING ...................................... 16

15.1. REPAIRS TO REFRIGERATION CIRCUITS BY QUALIFIED PERSONNEL .........................16

15.2. SCRAPPING SYSTEM UNITS................................................................................................16

16. TROUBLESHOOTING....................................................................................................................17

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1. GENERAL INFORMATION AND INTRODUCTION

This manual regards the systems designed for cooling, conserving and freezing at medium, low and very low
temperatures, with single and multiple circuits, identified with the symbols:

SP-UM-UMA MC – MCC -MCI
UMC- UMCA

The interconnections of the cooling and electrical circuits must be made on site by qualified personnel, who
must also ensure correct charging of refrigerant and strict observance of all professional and safety
standards (directive 97/23/CE).
The presence of pressurised and electrical equipment require specific qualifications of the personnel
assigned for these tasks.
As a general rule, all operations on the machine during installation and maintenance must only be performed
after disconnecting the electrical power supply.

1.1. SYSTEM TECHNICAL DATASHEET

This applies to each individual serial number.
It is an integral part of this document and specifies:

 The cooling circuit layout
 The description of the components installed
 Specifications of the electrical power supply
 Type and dimensions of equipment
 Setting sheet

The units are supplied with dry cooling circuitry and nitrogen pressurisation.

2. PROCEDURES BY CLIENT ON DELIVERY

On delivery of the equipment, the client should perform a thorough check of all contents.

2.1. CONDITION CHECK

The equipment leaves the supplier’s factory after precise testing and in perfect condition. Therefore, if any
damage is detected on delivery, this will have been caused during transport and must be reported to the
shipping agent and noted on the delivery documentation prior to acceptance.
The supplier or representative in the EU must be notified immediately in detail of the entity of any damage.

2.2. UNLOADING AND HANDLING OPERATIONS

These operations require adequate equipment based on the dimensions and weight of the equipment to be
moved.
Take great care to avoid sudden or violent movements.
Avoid using machine components as points of leverage.
Use suitable tools to unpack the equipment and avoid damage to the surface.

2.2.1 SLINGING AND PRECAUTIONS

The units are equipped with attachment points, clearly indicated by means of yellow labels in the form of
arrows. If the unit is packed with wooden lateral supports, these should be removed prior to installation.
The equipment can be lifted by means of a lift truck or a crane of adequate capacity.
Slinging must not generate transversal stress on the machine structure, which must also be protected from
friction with any lifting ropes used.
All relative precautions must be observed, including the constant use of anti-release devices, correct
balancing of the lift truck, load capacity limits and all other applicable safety standards.
If rollers are used for short transits, the relative distance between rollers must never exceed one metre.
Never upturn or incline machine parts.
For SP/UM/UMA/MC/MCI units: the remote control panel, featuring compact dimensions and weight, is not
difficult to handle; and is normally located inside the condensing unit, easily removed after detaching one of
the side panels. It should be removed from its packagingonly at the time of installation.

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2.2.2 POSITIONING

When possible, transfer the equipment directly from the transport means to the relative base, which must be
flat and stable; if this is not possible, equipment must always be placed on horizontal, stable and even
surfaces.

3. LOCATION AND POSITIONING

The following is envisaged:

• for outdoor units, installation outdoors without protections or sheltered, provided that there are no
obstructions to the complete and efficient removal of hot cooling air from the condenser (as specified in
the appendix).

• for machinery room units, ensure adequate clearances for maintenance and suitable room ventilation.

3.1. BASE AND POSITIONING

The base must be stable, able to withstand the weight of the unit, perfectly horizontal over the machine­ground contact zone and protected against the build-up of water.
Suitable rubber anti-vibration mounts or a neoprene rubber strip should be inserted between the machine
and the base.

3.1.1 OUTDOOR UNIT POSITIONING

See drawing/specifications.

These units must have sufficient perimeter clearances to enable maintenance and adequate space for
circulation of air around the condenser coil.
The minimum distance for air intake should be 0.8 m for single coils and 1.2 m for double or inclined coils.
During installation, personnel should also ensure free air circulation without obstacles both on intake and
delivery.

3.1.2 ACCESSIBILITY

To enable inspections, maintenance and repairs, the condensing units must be accessible from all sides.

3.1.3 CONDENSER COOLING AIR

On standard versions, and therefore in most cases, the condensing unit envisages forced air cooling of
condensers, with orthogonal flow, i.e. with horizontal intake and vertical delivery.
No obstacle must impair free flow circulation, therefore:

• intake ports must be completely free

• filters protecting the ports must be cleaned periodically, as specified in the chapter on maintenance and

in any event when clogged, for example during springtime when the air is filled with fluff from poplar
trees.

• the upper space must remain totally free, also from hanging tree branches.

3.1.4 CONDENSER COOLING WATER

All suitable precautions must be taken and adequate supervision must be ensured to eliminate the risk of
water freezing in the equipment. If the equipment is subject to prolonged disuse, the relative circuits must be
emptied completely.
If this is not carried out, serious damage could be caused, also due to water entering the cooling circuit.

It is strongly recommended to install an adequate filter on the water inlet to the condenser.

3.1.5 ELECTRICAL POWER SUPPLY LINE

The system electrical line, with input on the electrical panel terminal board located in the unit or on the main
disconnector switch, must be suitably sized on the basis of maximum current absorption.
The selection of materials, sizing, installation procedures and testing must comply with national standards.
The power line must be suitably protected according to current standards.

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3.1.6 EARTHING

The installation must be connected to the earthing line, using the terminal supplied by the manufacturer,
before the initial power-up of the equipment during installation.
Connections, installation of the earthing line, total efficiency of the latter and compliance with current
standards throughout use is the responsibility of the user.

3.2. POSITION OF EVAPORATOR UNITS AND THERMOSTAT BULB

Refer to the relative operation and maintenance manual.

4. REFRIGERATION CONNECTIONS REQUIRE QUALIFIED PERSONNEL

THE UNITS ARE ASSEMBLED/CONSTRUCTED IN COMPLIANCE WITH PED DIRECTIVE 97/23/EC. ALL
CONNECTIONS ON THE SYSTEM MUST BE MADE BY QUALIFIED PERSONNEL AND CERTIFIED IN
OBSERVANCE OF THE ABOVE STANDARDS.
IT IS THE CLIENT’S RESPONSIBILITY TO EQUIP THE ASSEMBLED CIRCUIT WITH SUITABLE SAFETY
DEVICES IN ACCORDANCE WITH DIRECTIVE 97/23/EC. IT IS ALSO THE CLIENT’S RESPONSIBILITY
TO DRAW UP THE INSTALLATION DESIGN AND COLLECT CERTIFICATION OF ALL ASSEMBLED
COMPONENTS AS WELL AS THAT OF THE CIRCUIT WELDERS FOR SUBSEQUENT REGISTRATION
AT THE COMPETENT OFFICES.
THESE INSTRUCTIONS ARE INTENDED AS A REFERENCE TO PROFESSIONAL STANDARDS TO
ENSURE INTEGRITY OF THE CONDENSING UNIT, WHICH COULD BE DAMAGED BY INCORRECT
CONNECTIONS.

• Circuit leaks are not admitted. The refrigerant is a pollutant and a reduction in charge may impair thermo­dynamic performance of the system thus increasing electrical power consumption.

• the routing of pipelines and relative sizing must ensure correct operation and circulation of the lubricant
oil of the compressors.

• impurities must not be present in the circuit as these may obstruct correct operation of the thermostatic
valves and damage the compressor.

• the circuit must not be subject to humidity as this alters the characteristics of the lubricant oil with the risk
of damage to the compressor motor windings and may block operation of the thermostatic valves.

• no air must be present in the circuit as this constitutes a hazard and can cause malfunctions or damage
of the compressor.

• On systems with remote condensation a check valve should be installed on the discharge line in the
vicinity of the unit.

4.1. PIPELINES

ALL PIPELINES, BENDS AND UNIONS MUST BE CERTIFIED ACCORDING TO THE DIRECTIVE
97/23/EC AND COMPLY WITH NATIONAL STANDARDS.
ALL WELDINGS MUST BE PERFORMED BY QUALIFIED PERSONNEL AND CERTIFIED ACCORDING
TO THE PED DIRECTIVE 97/23/EC AND COMPLY WITH NATIONAL STANDARDS.

Connection pipelines must, in principle, be as short as possible, both to reduce pressure drops and thereby
maintain system performance, and to reduce to overall volume occupied by the refrigerant; therefore the
quantity of the latter remains proportional to the volume.

4.2. COLD PIPELINE INSULATION

The pipelines, in particular the cool intake lines, must be efficiently insulated.
This prevents dispersion and condensation of humidity with consequent oxidation and dripping.

4.3. SEALING EFFICIENCY TESTING

In a cooling system, sealing of the unit is absolutely essential.
Sealing testing is therefore a fundamental phase in installation and as such must be carried out with great
care.

4.4. UNIT SEALING EFFICIENCY TEST

The unit is delivered immediately after a sealing test in nitrogen pressure conditions.

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Therefore, before joining operations, the pressure must be discharged from the machine, paying attention to
the fact that this machine is pressurised.
If the machine is already discharged, the following may be required:

1. locate the leakage

2. repair

3. pressurise the circuit with nitrogen

4. seal the circuit after inserting a control pressure gauge

5. verify that in the subsequent 12 hours the pressure reading on the gauge does not fall

The operation of joining the unit and utilities must only be performed after setting up all connection lines from
the utilities to the machine.

4.5. SYSTEM SEALING EFFICIENCY CHECK

Refer to installation design according to current EC standards.

5. ELECTRICAL CONNECTIONS AND HOOK-UP

ELECTRICAL CONNECTIONS ARE THE TASK AND RESPONSIBILITY OF THE USER. THESE
INSTRUCTIONS ARE INTENDED AS A REFERENCE TO PROFESSIONAL STANDARDS TO ENSURE
INTEGRITY OF THE CONTROL UNIT, WHICH COULD BE DAMAGED BY INCORRECT CONNECTIONS.
The unit and relative electrical accessories comply with the low voltage directive 73/23/EC. Make all
electrical connections to the unit according to indications in the electrical wiring diagram enclosed. Take care
to observe the safety standards EN 60204, EN 60335 and all national standards.

The selection of materials, sizing, installation procedures and testing must comply with current national
standards.

5.1. PRECAUTIONS AND CHECKS

Before proceeding with any installation or maintenance operation on the electrical system, the operator must
ensure that the system is disconnected from the power supply and that the latter cannot be switched on
inadvertently during the operations required.

5.1.1 POWER SUPPLY AND TOLERANCES

First of all ensure that parameters available for power supply: number of phases, voltage and frequency,
correspond to those specified on the dataplate on board the machine.
The power supply voltage must never be subject to variations exceeding ±5% with respect to the nominal
values. Unbalance between the phases must never exceed 5%.

5.2. ELECTRICAL DRAWING

5.2.1 WIRE DIMENSIONS

The section of the wires must be suited to the current conveyed and the distances to be covered (the
maximum current absorption values are stated on the electrical wiring diagram enclosed).
Check absorption values on the plates affixed to each utility.

5.2.2 ELECTRICAL CONNECTIONS BETWEEN THE CONDENSING UNIT AND AIR EVAPORATORS.

These connections, to be made according to the wiring diagram enclosed, mainly concern:

• fan unit, defrost sensor, air evaporator thermal overload protections, defrost resistances,

power interlock

5.2.3 REMOTE EVAPORATORS/CONDENSERS – SAFETY SWITCH

The UMA/UM/SP/MC/MCI units are designed with direct power supply to the evaporators.
All maintenance operations require compulsory disconnection of the machine electric power supply; before
proceeding with work affix a notice stating “maintenance in progress” on the machine.
The machine power must be shut off when the machine is stationary.
If required, an emergency switch can be fitted and connected between the terminals of the external interlock,
marked with the symbol “IE”, on the terminal board of the panel on board the machine, which when activated
shuts off the auxiliary power supply circuit and stops the machine.

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5.2.4 ELECTRICAL CONNECTIONS BETWEEN THE CONDENSING UNIT AND CONTROL PANEL.

thermostat sensor, compressor control elements, defrost indicator lamp, start-stop indicator lamps

5.2.5 POSITION OF THERMOSTAT SENSOR

The position of the thermostat sensor must be chosen with care, avoiding impact with air in anomalous
conditions such as air deriving from doors opened in a cold room, from compensation valves or other. For
further information refer to the evaporator operation and maintenance manual.

5.3. TESTS

5.3.1 PRELIMINARY VISUAL INSPECTIONS

CEI EN 60204-1, visual inspection:

1. Presence and identification of main terminal PE.

2. Identification of all other terminals with graphic symbol of earth or coloured yellow/green.

3. Exclusive purpose of terminals for equipotential bonding connections.

4. Connection of one wire only to each terminal.

5. Yellow/green colouring of possible insulation on protection wires.

6. Absence of active wires with yellow/green insulation.

7. Absence of tubes or ducts used as protection wire.

8. Absence of fuses, circuit breakers or disconnect switches for equipotential bonding protection.

9. Conformity of wire section to minimum values stated by standards.

10. Check that electrical connections have been made correctly.

In particular the connections of the phases, after opening the box containing the compressor terminal board,
must be made according to instructions on the compressor electrical enclosure, according to the type of
compressor – direct or part winding start-up – and the machine wiring diagram.

6. REFRIGERANT CHARGING OPERATIONS REQUIRE QUALIFIED PERSONNEL

THE REFRIGERANT CHARGING OPERATIONS, PARTIAL OR COMPLETE, ARE THE TASK AND
RESPONSIBILITY OF THE USER.
THESE INSTRUCTIONS ARE INTENDED AS A REFERENCE TO PROFESSIONAL STANDARDS TO
ENSURE INTEGRITY OF THE CONTROL UNIT, WHICH COULD BE DAMAGED BY INCORRECT
CHARGING.
The procedure can be started after all refrigeration pipelines have been laid and electrical connections
completed.

6.1. REFRIGERANT TYPE AND LUBRICANT OIL

The machine dataplate states the following both for the refrigerant and lubricant oil:

• Product type

6.2. VACUUMING THE UNIT

Open all valves and solenoid valves on the circuit. Eliminate air from the entire system, including the
compressor on the intake side and high pressure side, using a vacuum pump. On completion of the
operation a permanent vacuum must be obtained of below 1.5 mbar.
NEVER START UP THE COMPRESSOR IN VACUUM CONDITIONS
NEVER POWER UP THE MACHINE EVEN FOR CHECKING PURPOSES

6.3. REFRIGERANT CHARGING

Only charge with the type of refrigerant stated on the machine dataplate
Before charging:

¾ Activate the compressor casing resistance
¾ Check the oil level in the compressors,
¾ Do not start up the compressor

Charge the liquid refrigerant directly in the liquid receiver.

6.4. CHARGE CHECK

The charge level must be determined with precision, an excessively low or high quantity of refrigerant can
impair correct operation.

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IMMEDIATELY AFTER CHARGING, CHECK SYSTEM SEALING EFFICIENCY, TESTING ALL
COUPLINGS WITH A DETECTOR ABLE TO READ MINIMAL REFRIGERANT LEAKS.
IN THE RARE CASE THAT A LEAK IS DETECTED, DO NOT PROCEED WITH REPAIRS BY WELDING
UNTIL A REFRIGERATION TECHNICIAN HAS BEEN CALLED AND THE RELATIVE SECTION HAS
BEEN CLEANED THOROUGHLY TO REMOVE ALL TRACES OF OIL. BURNT RESIDUE FROM
WELDING TEMPERATURES WILL IMPAIR SYSTEM FUNCTIONALITY AND RELIABILITY.
CAUTION: IF INSULATION IS MADE OF OLD PRODUCTION POLYURETHANE FOAM, THE DETECTOR
MAY READ THE PRESENCE OF GASES SIMILAR TO REFRIGERANT GASES USED FOR THE
PRODUCTION OF THIS TYPE OF FOAM. IN THE EVENT OF ANY DOUBT, REMOVE PART OF THE
INSULATION TEMPORARILY. THE PIPELINE INSULATION SHOULD ONLY BE COMPLETED AFTER
THE LAST CHECK.

7. INSPECTION OF THE CONDENSER FANS REQUIRES QUALIFIED PERSONNEL.

Installation must take into account the compulsory clearances required for optimal circulation of air.
Each fan has the blade protected against hazardous accidental contact; these guards must never be
removed or tampered with.

7.1. CHECKING THE DIRECTION OF ROTATION

The fans reach the specified flow rate by rotating in a specific direction as indicated on the unit.
Check and, if necessary, invert the phases to ensure the correct direction of rotation.

7.2. ELIMINATION OF OBSTRUCTIONS TO AIR FLOW

The air flow must never be obstructed.
Refer to the specifications.
Cooling air must never be contaminated; avoid intake from pollutant industrial facilities or from manure
yards/slurry or intensive cattle breeding centres, sources of ammonia pollutants.
The condenser coils are protected by metal filters which may clog; keep the front of the intake zone clean at
all times.

8. CONTROL AND STATUS PANEL

8.1. ACCESS PROCEDURE (only on enclosed units for outdoor installation)

To access the control status panel, remove the snap-fit protection panel by lifting and pulling outwards as
shown, to detach it from the main panel.
The panel must always be refitted with care after inspection.

8.2. PROTECTION CALIBRATION AND CHECKS

For these types of operation, to be performed by qualified personnel, access to the electrical panel interior is
required.

8.3. ACCESS RESTRICTION

Before opening the hinged panel, by means of the specific key for access to the interior, the system power
must be shut off by turning the disconnect switch lever located on the door of the electrical panel from
position 1 to 0, and taking suitable precautions to avoid inadvertent activation.
The machine power must be shut off when the machine is stationary.

8.4. SETTABLE PROTECTIONS

Access to the interior of the panel also enables access to the protections for relative calibration procedures.
The calibration value is established and set during equipment testing prior to delivery; any modification to
these values must be made by qualified personnel and after verifying the specific purpose.
Lower values may cause an unjustifiable shutdown of the utility concerned while excessive values may
cause burnout due to the lack of protection.

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8.5. FUSE REPLACEMENT

This operation also requires access to the interior of the panel.
A blown fuse indicates a serious malfunction of connections or utility, or may be caused by an external
source, at times due to atmospheric discharges.
Before replacement, identify the cause of the fault and remedy.
Always replace fuses of with versions of the same type and capacity.

9. AUTOMATIC FUNCTIONALITIES

These are the units that enable automatic system operation.

9.1. COLD ROOM TEMPERATURE CONTROL

The control of the cold room temperature is by means of the thermostat installed on the control panel. This
instrument – refer to the specific instructions enclosed – is normally electronic.

9.2. DEFROST MANAGEMENT

Refer to the specific instructions for the instrument and evaporator.

9.3. CONDENSATION PRESSURE CONTROL

Ensure the correct type of condensation control with reference to the electrical wiring diagram.
Maintain the condensation pressure set points specified in appendix . The machine is designed to operate in
these specific conditions.
In the case of water type condensers, install a pressure switch valve for condensation control.

9.4. MOP ELEMENT IN THERMOSTATIC VALVES

Always use thermostatic valves with MOP (Max operating pressure) elements.

9.5. PUMP DOWN MODE OPERATION

If this solution is adopted in systems with piston or screw compressors, ensure that the pressure switch trip
threshold for shutdown in Pump-down mode is at least 0.5 bar above the low pressure safety pressure
switch threshold.

If using scroll compressors, shutdown in pump-down mode is prohibited.

9.6. OIL TEMPERATURE CONTROL IN SYSTEMS WITH SCREW COMPRESSORS

In systems with semi-hermetic screw compressors used at low temperatures, ensure that the oil temperature
is maintained within a suitable range. For this purpose an air oil cooler with finned coil or water type heat
exchanger is installed to prevent the oil from reaching high temperatures, and a thermostat-controlled
electric heater is inserted in the oil separator, fitted with an electro-mechanical control thermostat to limit
temperature reductions. The control of the air oil cooler is by means of a multi-step thermostat which
activates and deactivates the fans, varying the air flow rate and consequently heat exchange. In the case of
water type exchangers, the oil temperature is maintained constant by a pressure controlled valve which acts
on the water flow rate.
In both cases refer to the documentation enclosed and the wiring diagram for further details.

10. PROTECTIONS

The system is equipped with protections to safeguard against anomalous situations, acting both on the
pressurised circuit and the power circuit.
It is the client’s responsibility to equip the assembled circuit with suitable safety devices in accordance with
directive 97/23/EC and relative national standards.

10.1. PRESSURE OVERLOAD IN COOLING CIRCUIT

Protection against excessive pressure of refrigerant in the delivery line, which can impair system
functionality and constitutes a hazard to personnel, features two activation stages.

- when pressure reaches values over 25 bar, the maximum pressure switch trips, according to factory

settings, to cause system shutdown. Operation can be restored manually, only after eliminating the cause of
the problem.

- if the maximum pressure switch does not trip, the safety valve is activated. Activation of this device, legally

compulsory on all pressure equipment, causes the partial or total exit and loss of the refrigerant charged in
the system and must be considered an exceptional event.

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10.2. REFRIGERANT PRESSURE DEFECT

If pressure falls to below factory settings, the minimum pressure switch trips.
This shuts down the compressor motor, but not permanently. If the intake pressure returns to normal values,
the equipment re-enables start-up. This is acceptable if it concerns a transitory occurrence, but if repeated
requires specific maintenance.

10.3. INSUFFICIENT COMPRESSOR LUBRICATION

The oil pressure switch is fitted on all systems with compressors that have pump-operated lubrication (inside
compressor). Activation is delayed by a 120” interval to filter pressure transients on compressor start-up.
Reset is manual by means of the pushbutton on the front panel of the pressure switch, when possible to be
performed after around 15’.
Obviously the oil level must be checked immediately.
If the pressure switch requires replacement, use one of the same brand and type, or request information on
other admissible models from the manufacturer.
In systems with semi-hermetic screw compressors, safety of the oil return line to the compressor, and thus
adequate internal lubrication is ensured by a flow switch installed on the compressor oil return line from the
separator. The signal is sent to an electronic module and activation is delayed by a few seconds by means
of a timer to avoid flow stabilising transients after compressor re-start.

10.4. INSUFFICIENT OIL LEVEL IN COMPRESSOR

In systems with semi-hermetic screw compressors, a float is installed in the oil separator to indicate low
levels and thus the need to replenish oil levels in the system. This signal is delayed by a few minutes to
prevent fluctuations on system start-up from generating unjustified alarms.

10.5. COMPRESSOR MOTOR TEMPERATURE OVERLOAD thermal cutout module

On systems with semi-hermetic, reciprocating, screw or medium output scroll compressors no lower than 7.5
HP, thermal cutouts are electronic, based on thermistors inserted in each of the motor phase windings.
These sensors are connected to an external electronic module, capable of reading resistance unbalance,
and therefore temperature levels, and activating to shut off the main power supply.

On systems with hermetic reciprocating and low output scroll compressors less than 7.5 HP,
thermal cutouts are internal and interrupt continuity of the motor phase windings, shutting down
the machine without any external signal. For further information refer to the compressor operation
and maintenance manual.

10.6. CONDENSER FAN MOTOR TEMPERATURE OVERLOAD

On all systems with 3-phase motor condenser fans, thermal protection of the motors is guaranteed by
means of a thermal relay located downline of the power supply contactor of the corresponding motor.
Activation of this device does not shut down the compressor and therefore the system, but only power
supply to the motor; it is the condensation pressure that on increase trips the maximum pressure switch and
shuts down the compressor.
Reset is manual by means of the pushbutton on the front panel of the relay inside the electrical panel.
Indication of the fault is by means of a lamp on the door of the electrical panel or by means of the alarm and
defrost management instrument inside the same electrical panel on board the machine.

10.7. AIR EVAPORATOR FAN MOTOR TEMPERATURE OVERLOAD

On all systems with air evaporators fitted with single phase electric motors, thermal protection of the motors
is guaranteed by means of an internal relay which shuts down power supply to the single motor, without
however generating an external signal of the fault. When the winding temperature falls to admissible values,
power supply is automatically restored.
On systems where the air evaporators have 3-phase electric motors, the temperature overload is indicated
by means of an internal thermal relay, known as klixon. Normally, for air coolers with multiple fans, a series
of all klixons is implemented and indicated on the unit electrical panel. In this way the alarm of a single fan
shuts down the compressor. Reset is automatic and occurs only after the winding temperature has fallen to
admissible values (unless an interlock is envisaged on the machine control electronic instrument).
Indication of the fault is by means of a lamp on the door of the electrical panel or by means of the alarm and
defrost management instrument inside the same electrical panel on board the machine.

10.8. INCORRECT PHASE SEQUENCE

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Control of the electrical phase sequence is important to guarantee correct rotation of the motor in screw and
scroll compressors.
In the first case, the correct sequence is guaranteed by an electronic controller named INT389 which also
checks for phase failure, winding temperature overload alarms and compressor start-up delays. Activation of
this device shuts off power supply to the compressor.
In the second case a simpler electronic controller is installed, which, in the case of incorrect phase
sequence, shuts off power supply of the entire auxiliary circuit and therefore the compressor.

11. SIGNALS

As well as the luminous indicators and instruments installed on the panel of the electrical panel, identifiable
on the electrical wiring diagram and documentation enclosed, the circuit envisages visual indicator lamps,
the access to which, in the case of outdoor installations, may require removal of one or more metal panels
enclosing the structure of the condensing unit.
These panels are snap-fit and must be lifted and pulled outwards to remove. Fixing screws may need to be
loosened prior to removal.
Always refit these panels with care as they convey the cooling air of the condensers.

11.1. LIQUID TRANSFER SIGHT GAUGE

This is a transparent gauge installed on the liquid line and enables visual inspection of the charge status. At
full operating speed, the flow must be continuous without foam or gas bubbles.
If significant turbulence with the presence of gas is noted, take care to wait a few minutes before correcting
the charge level. This may be a transitory event caused by rapid opening of a thermostatic valve.

11.2. HUMIDITY INDICATOR

The level gauge also has a coloured element that indicates whether the refrigerant is dry or contains
humidity.
On the basis of the gauge indications, if humidity is present, replace the drier cartridges, drain and recharge
the machine.

11.3. OIL LEVEL SIGHT GAUGE

The compressor casing is fitted with an oil level gauge which also indicates minimum and maximum
admissible level limits. If replenishment is required, also use exclusively the oil type stated on the machine
dataplate and in the documentation.

The oil level must be checked immediately after compressor start-up and at regular intervals during operation.

11.4. REFRIGERANT PRESSURE GAUGES

Pressure gauges are installed on the unit to check pressure on various parts of the circuit.
hermetic and semi-hermetic compressors without oil pump: pressure gauge on high pressure and low
pressure sides.

• semi-hermetic compressors: pressure gauge on high pressure and low pressure sides and on the oil
pump.

12. SYSTEM START-UP IN PRESENCE OF QUALIFIED PERSONNEL

Initial system start-up requires observance and attention to a number of procedures.

12.1. PRELIMINARY CHECKS

These checks must be performed on system start-up before reaching operating speed.

12.1.1 CASING PREHEATING

Activate the compressor casing resistance
The casing oil temperature before start-up must be around 15-20 °C higher than the ambient temperature or
the saturation temperature on the intake side.
Units designed for outdoor installation, in environments with very low minimum ambient temperatures may
also be equipped with electrical resistances, which have the same function as the casing resistances, also
on the intake manifold and the oil reserve tank.

12.1.2 PRECAUTIONS

• Check once again to ensure correct installation of the cooling and electrical circuits, ensuring in

particular correct earthing of the equipment.

• Ensure that all valves on the cooling circuit are open, and that bypass valves to the outside are closed

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and fitted with caps.

• Ensure that the voltage on the terminals between the phases and neutral is as specified.

• For part-winding motors: strictly observe the order of the part-windings indicated on the electrical wiring

diagram enclosed. The delay in connection of the second part-winding must be 0.5 s (max. 1 s).

• Check the values of the timed relays.

• Check the oil level in the compressors (in the sector marked in the level gauge)

• Check that the control and safety device settings comply with the calibration table values enclosed and

national standards.

12.1.3 CHECKING THE DIRECTION OF COMPRESSOR ROTATION

The direction of reciprocating compressor can be either one; while the correct direction of screw and scroll
compressor rotation must be checked.
For systems with these compressors, before starting up the unit:

• Connect a pressure gauge to the intake valve coupling

• Close the intake valve fully and then open by one turn

• On semi-hermetic screw compressors: close the solenoid valve on the oil injection line (remove the coil).

• Start up the compressor briefly (0.5 – 1 sec)

• Correct rotation: pressure of the gauge on intake lowers immediately

Incorrect rotation: pressure of the gauge on intake increases and the electronic protection module trips.
In this case invert the two phases on the terminal board.

On semi-hermetic screw compressors: after checking, re-connect the solenoid coil of the oil injection line

12.1.4 CHECKING THE DIRECTION OF FAN ROTATION

Check the direction of fan rotation with 3-phase motors installed, according t the unit model, on:

• air evaporators

• condenser

• head sections for compressor cooling

• finned oil cooling coils

• other special equipment with 3-phase fans

To check, ensure that the direction of the air flow guarantees correct operation of the equipment. Otherwise,
invert two of the three power supply wires upline of the relative contactor, taking care that the direction of
rotation of other system motors is not altered.

12.1.5 PANEL CLOSURE CHECK

Ensure that the panels of the condensing unit structure are positioned correctly and closed to avoid
difficulties in the correct use of the condenser cooling air.

12.1.6 REFRIGERANT CHARGE CHECK

On reaching operating speed, ensure the correct flow of refrigerant via the relative sight gauge on the liquid
line.

12.1.7 LUBRICANT OIL RETURN CHECK

Check compressor lubrication immediately after start-up.
¾ Oil level from ¼ to ¾ of the sight gauge (repeated checks are recommended during the initial hours of

operation).

¾ On systems with oil pumps, check that the differential pressure of the pump (indicated on the oil

pressure gauge) is between 1.4 and 3.5 bar.

During the start-up phase, some foam may form on the oil, which should be minimised on reaching stable
operating conditions. If this does not occur, this may indicate a high concentration of liquid in the intake gas.

12.1.8 THERMOSTATIC VALVE CALIBRATION CHECK

See instructions in the specific documentation.

12.1.9 FILTRATION ON SUCTION ON INITIAL START-UP

The units with semi-hermetic screw compressors (or units to client specs) are equipped with containers for
mechanical filters on the intake line.
Before starting up the system for the first time, a mesh cartridge should be inserted, which should be
checked after around four hours of operation, cleaning if necessary and repeating this check periodically
until it can be guaranteed that all impurities have been removed.

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At this point the container without cartridge should be closed, to eliminate any cause of pressure drops.

13. PRECAUTIONS IN THE EVENT OF PROLONGED DISUSE

Decommissioning for prolonged disuse requires a number of precautions.

13.1. CLOSURE OF REFRIGERANT VALVES

In the event of prolonged shutdown, the following operations are recommended:

• close the valve downline of the liquid receiver;

• After restricting most of the refrigerant charge to the high pressure side, close the compressor delivery

valve;

during the re-start phase, ensure that all valves are completely open

13.2. RE-START AFTER PROLONGED SHUTDOWNS

This operation requires observance of a specific procedure and a number of precautions.

13.2.1 ADVANCE POWER-UP

This preliminary operation is important together with the casing preheating procedure.

13.2.2 CHECKS AND PRECAUTIONS

The procedure regarding system start-up must be repeated, observing all relative precautions.

14. PERIODIC MAINTENANCE BY QUALIFIED PERSONNEL

Check the system regularly according to national regulations.
The following section provides general instructions regarding periodic maintenance required for units and
divided according to the specific frequency required.
The end of this chapter provides specifications regarding maintenance operations recommended according
to the type of compressor installed.
In any event refer to the specific component operation and maintenance manual for further information and
procedures.

14.1. PRECAUTIONS

All maintenance operations must be performed by, or under the direct supervision and responsibility of
qualified personnel.
The system must be completely stationary and disconnected from the power supply before any operation.
Disconnect the power supply only when the system is already stopped by means the automatic control
devices.

14.2. MONTHLY MAINTENANCE (OR EVERY 200 HOURS)

These operations are required on the units every month or every 200 hours of operation.

14.2.1 SAFETY DEVICE AND CONTROL CHECK

Check operation of all control and safety devices such as pressure switches, safety valves electronic system
management instruments.

14.2.2 ELECTRIC TERMINAL TIGHTENING CHECK

Check tightening of all electric terminals both inside the electrical panels and on the terminal boards of all
utilities.
Take care also to check tightening of all fuses.

14.2.3 ELECTRIC CONTACT CONDITION CHECK

Clean fixed and mobile contacts of all contactors, replacing in the event of wear or damage.

14.2.4 REFRIGERANT AND OIL LEAK CHECK

Visually check the entire cooling circuit, also inside the machines, to locate possible leaks of refrigerant,
which are also indicated by traces of lubricant oil.
Act immediately and investigate if in doubt.

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Also ensure the regular flow of refrigerant via the sight gauge on the liquid line. This operation should be
performed with care as the system must remain in operation.

14.2.5 CASING HEATER CHECK

Check efficiency of the casing heater.
If necessary, measure continuity by means of a suitable instrument.

14.2.6 EARTHING EFFICIENCY CHECK

Check the earthing terminal and ensure efficiency by means of a suitable instrument.

14.2.7 CONDENSER CLEANING

Cleaning must be by means of compressed air on the internal side, with the jet in the opposite direction to
that of air intake. Repeat the same operation also for the condenser finned coil, taking care due to the
cutting hazard present in this area.
To clean filters (if required) and remove all adherent or oily particles, use a pressurised water jet, also
detergents provided that these are neutral pH. Dry by means of compressed air.
Refit filters with care before restarting the system.
In some periods, often in springtime, cleaning may need to be more frequent due to the presence of vegetal
impurities in the air. A clogged filter is indicated by an increase in condensation pressure.

14.2.8 MECHANICAL FILTERS ON INTAKE (when fitted)

To fit or replace filters, proceed as follows:

• close the inlet valve and valves on intake of the compressors.

• discharge and collect the refrigerant trapped between valves.

• proceed with replacement or cleaning as required.

• close the filter container carefully, replacing the seal when possible;

vacuum the machine

14.3. QUARTERLY MAINTENANCE (OR EVERY 800 HOURS)

These operations are required on the units every fourth month or every 800 hours of operation.

14.3.1 REFRIGERANT HUMIDITY CHECK

Carefully examine the colour of the sensitive humidity element in the sight gauge on the liquid line.
Compare with the specifications table on the gauge instructions to determine possible presence of water. All
is correct if the reading is “dry”
If humidity is detected, shut down the unit immediately and replace the drier cartridges, all refrigerant charge
and the oil present in the circuit.

14.3.2 DRIER FILTER CARTRIDGE REPLACEMENT

For replacement, with the plant stationary, proceed as follows:

• isolate the circuit section with the filter by closing the valves up and downline of the filter.

• recover the gas in the isolated section

• replace the cartridge

• vacuum the isolated pipeline section

• open the valves previously closed.

DO NOT UNPACK THE CARTRIDGES UNTIL THE TIME OF INSTALLATION THIS GUARANTEES
PERFECT CONSERVATION OF THE COMPONENT

14.3.3 COMPRESSOR NOISE – VIBRATION CHECK

Check the entire system, in particular the pipelines and capillary tubes to ensure there are no abnormal
vibrations. If necessary, take suitable additional safety measures.
The presence of strong vibrations may cause damage to the pipelines and leakage of refrigerant and oil onto
components of the plant.

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15. PROTECTING THE ENVIRONMENT – MAINTENANCE - SCRAPPING

Refrigerant fluids are subject to legal regulations that prohibit disposal into the environment, with compulsory
recovery.
Lubricant oils are also subject to similar regulations.
Take into account the above when performing maintenance or scrapping refrigeration systems.

15.1. REPAIRS TO REFRIGERATION CIRCUITS BY QUALIFIED PERSONNEL

ALL PIPELINES, BENDS AND UNIONS MUST BE CERTIFIED ACCORDING TO THE DIRECTIVE
97/23/EC AND COMPLY WITH NATIONAL STANDARDS. ALL WELDINGS MUST BE PERFORMED BY
QUALIFIED PERSONNEL AND CERTIFIED ACCORDING TO THE PED DIRECTIVE 97/23/EC AND
COMPLY WITH NATIONAL STANDARDS.
In some cases and always when welding is required, the circuit must be emptied of refrigerant.
If the refrigerant cannot be recovered, it must be returned to the retailer or suitable authorised waste
disposal firms.

15.2. SCRAPPING SYSTEM UNITS

When the system is to be scrapped, the following procedures are compulsory:

1. total recovery of refrigerant fluid with adequate equipment and delivery to authorised personnel for
recovery and disposal.

2. the same procedure applies to lubricant oil in the circuit, in particular that in the compressor casing and
filter cartridges impregnated in oil.

separate the components into categories, such as iron and steel, copper and electrical wires, electric motors

and motor compressors, soundproofing panels in synthetic foam and heat insulation material. The
separated materials must be delivered to suitable collection centres for recycling.

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16. TROUBLESHOOTING

Fault finding procedures and repairs must be performed by qualified personnel or may require intervention of
the manufacturer.
In the event of faults or malfunctions take care to observe the following section.
Excessive confidence in procedures may cause damage to the environment or physical injury.
All operations must be performed with the machine disconnected from the power supply.

TROUBLESHOOTING TABLE

TROUBLE CAUSE SOLUTION

Condensing pressure too high.
Air cooled condenser

Filters are dirty.

1Fan or fan motor broken.

Air flow direction not correct

Clean the filter and the condenser
surface. Remove possible obstacles in
order to have a correct air flow.

Change the fan.

Change the rotation direction, with the

inversion of 2 of the 3 phases.
Condensing pressure too high.
Water cooled condenser

The internal surface of the condenser is
dirty.

The water flow is not correct (too small)

Clean the internal surface of the

exchanger with proper products.

Check the functioning of the pump

system.
Condensing pressure too low.
Air cooled condenser

Low temperature of the ambient air.

Too much air flow through the coils.

In both cases set the correct condensing

pressure.

Condensing pressure is too low
Water cooled condensers

Water temperature is too low.

Too big quantity of water through
condenser

In both cases set the correct condensing

pressure.

Condensing pressure is not
stable.

The differential of the condensing
pressure switch is too big.

Set in the correct way the differential of

condensing pressure switch.

Discharge pipe temperature is
low.

Too much liquid in suction. Check the expansion valve setting, and its

correct installation.

Low liquid level in the receiver. Lack of refrigerant in the plant. Find the reason (possible leakages);

repair the problem, and fulfill refrigerant if

necessary.

High liquid level in the receiver. Too much refrigerant charged in the

plant.

Take out some refrigerant from the plant,

keeping the correct condensing

temperature; verify that the sight glass

does not show any vapour bubble.

Liquid filter cold, or eventually
covered by frost

Dirty filter , because of impurities,acidity
or humidity.

Check if there are impurities: if necessary

clean the plant or substitute the filter. If

there is humidity or acidity, change the

freon and the oil charge.

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TROUBLE CAUSE SOLUTION

Vapour bubbles on the sight glass. Low condensing pressure.

Liquid receiver shutoff valve not totally
open.

Lack of refrigerant in the plant.

See: “Condensing pressure too low”.

Open completely the shut off valve.

Add some refrigerant, after checking other
problems, in order not to increase too
much the refrigerant charge.

Too low Suction pressure. Low pressure switch broken or with a

wrong setting.

Change the pressure switch or set it in the
correct way.

Too low suction pressure. Lack of refrigerant in the evaporator due

to:

Low liquid level in the receiver.

Occlusion of the iquid filter.

Solenoid valve stalled.

Fault of expansion valve.

See: “Low liquid level in the receiver.”

See: “Vapour bubbles on the sight
glass” .

Check the correct functioning of it.

Change the expansion valve.

Frequent high pressure alarm

Wrong setting of the high pressure
switches.

Check that set value of the pressure
switches is correct and set according the
setting sheet.

Too high level of oil in the
crankcase.

Too much oil in the unit. Take out oil from the system until you

reach the correct quantity: Make sure that
the indication is not consequence of the
fact that there is refrigerant in the oil.

Too low level of oil in the
crankcase.

Not sufficient quantity of oil in the circuit.

Add some oil to the system until you
reach the correct quantity: Make sure that
the indication is not consequence of the
fact that there is a temporary condition
due to low oil return.

Boiling of the oil during
functionning.

Liquid return from the evaorator to the
crankcase of the compressor.

Check the Expansion valve setting.

Cooler fans not running, and
consequent stop of the unit.

Fan motor broken.

Voltage supply too low.

Lack of 1 phase.

Change it.

Check if the voltage is OK.

Verify it , measuring voltage between
phases on the terminal of the fan. Check
all the power alimentation supply.

Air temperature in the coldroom too
low.

Temperature probes are broken

Coldroom set point too low.

Change them.

Verify and change the set if necessary