OPERATING INSTRUCTIONS
INSTALLATION
COMMISSIONING
OPERATING
MAINTENANCE
(must be given to the end user in order to complete the
operating manual during the equipment service life)
HYBRID POWER PACKS COMBICOOL
Medium Temperature R134a
Low temperature CO2 cascade
SEMI-HERMETICS PISTONS BITZER COMPRESSORS
PED fluid group : 2
These operating instructions must be read at the delivery of the equipment and prior any operation on it.
Our technical department is at your disposal for any additional information (Tel : ++ 33 4 42 18 05 00).
This document is a translation of the French original version which prevails in all cases.
1/14
SUMMARY
S A F E T Y ............................................................................................................................ 3
1-
DESCRIPTION – OPERATIONS .................................................................................................... 8
2-
HANDLING - TRANSPORTATION................................................................................................. 8
3-
INSTALLATION ..................................................................................................................... 8
REFRIGERATION NETWORK CONNECTION .............................................................................................................................................................. 8
General information ................................................................................................................................................................................................... 8
BEFORE ANY WORK IS DONE ON THE REFRIGERATION CIRCUIT, THE HOLDING CHARGE MUST BE REMOVED. ............ 8
Rack Installation :....................................................................................................................................................................................................... 9
Installation of a liquid station provided separately. ........................................................................................................................................... 9
ELECTRICAL CONNECTIONS .........................................................................................................................................................................................10
General information ..................................................................................................................................................................................................10
Electrical motor wiring .............................................................................................................................................................................................10
Variable speed drive on compressors and Fan motors.......................................................................................................................................10
ADDITIONAL SAFETY CONTROLS ..............................................................................................................................................................................10
Safety Features .......................................................................................................................................................................................................10
Crankcase heaters ....................................................................................................................................................................................................10
AUTOMATIC MECHANICAL DEVICES .........................................................................................................................................................................10
4-
START-UP OPERATION .......................................................................................................... 11
PRELIMINARY CHECKS AND OPERATIONS............................................................................................................................................................... 11
General information .................................................................................................................................................................................................. 11
Leaks testing .............................................................................................................................................................................................................. 11
Dehydration of circuits ........................................................................................................................................................................................... 11
Oil Level Check .......................................................................................................................................................................................................... 11
Oils ................................................................................................................................................................................................................................ 11
Energise the crankcase heaters............................................................................................................................................................................. 11
Refrigerant Fluid Charge ........................................................................................................................................................................................ 11
Pre-Setting And Checking of Safety Systems ..................................................................................................................................................12
Start-up of compressors .........................................................................................................................................................................................12
Remainder of charge .................................................................................................................................................................................................12
OPERATING CHECKS ........................................................................................................................................................................................................12
5-
MAINTENANCE ................................................................................................................... 12
EVERY YEAR IN ADDITION TO THE MONTHLY CHECKS:............................................................................ 12
6-
TROUBLESHOOTING.............................................................................................................. 13
EXAMPLES OF FAULTS AND SOLUTIONS .............................................................................................. 13
2/14
SAFETY
As professional, the installer must :
define the operating conditions of the refrigeration equipment under his own responsibility regarding the design. This device need
to be incorporated in machines conforming to the Machines Directive. Its commissioning is only authorized if it has been
incorporated in machines which fully satisfies the legal regulations.
complete and adapt these recommendations, if necessary, by adding other safeties and /or controls according to the refrigeration
equipment’s operating conditions.
have performed all the installing, commissioning and maintenance operations by qualified professionals and conforming with
standards EN 378, EN 14276, EN 13136, EN 13313, EN 60204 and EN 60335, the EU directives, the safety rules generally
recognized, sound engineering practice, the local regulations ; as well as those which may be set up, taking into account the
evolution of the technology and the regulations.
If the installation, the commissioning, the operating, the maintenance are not realized according to this operating instructions, the
responsibility of Profroid can not be involved.
completely inform the customer on the control, maintenance and follow-up of the refrigeration equipment.
The devices are delivered under pressurized nitrogen or dry air (make sure at reception that material is under pressure by using
a pressure gauge).
Respect the standard for transport and handling of pressure devices.
Install device in a space with sufficient ventilation regarding standards and regulations because device is under pressure of
nitrogen.
Very important : before performing any servicing operation on refrigeration equipment, the electric power supply must be turned
off. The contractor or the company in charge of the installation shall be responsible for carrying out the required instructions.
PROFOID disclaims any responsibility for change(s) or repair(s) on its devices made without its prior agreement.
The devices are exclusively intended for professionals, for refrigeration purposes and for their limits of use.
The identification of device and his range of use are written on the name plate. The name plate is stuck on device. The name plate is
joined to this operating instructions (.pdf). The complete installation must be designed and used not to exceed the range of use. Device
is designed for the following maximum pressures : PS (LP) = 25 bar and PS (HP) = 45 bar R744 side and PS (LP) = 15 bar and PS (HP) =
19 bar R134a side.
The user or operator shall ensure the control and maintenance of the equipment with qualified professional complying with the
instructions below, possibly completed by the installer. For these operations, the standards and directives mentioned above remain
useful.
This is also available during the stop of the refrigeration installation.
The average life cycle for the design of our devices is of a minimum of 10 years, provided if you follow our operating instructions.
Profroid cannot be held responsible in case of violation to the recommendations of them.
Piping of Profroid equipment are made with different types :
in copper, standard NF EN 12735
in steel, standard NF EN 10216-2 (type P265GH ; n° 1.0425)
in stainless steel, standard NF EN 10217-7 (type 304L – X2CrNi18-9 ; n° 1.4307)
These piping must be inspected regularly following standards, sound engineering practice and local regulations in the country of use.
3/14
Specifics Safety instruction for CO2
Dry ice can form when liquid R744 expands below the triple point of 5.2 bar. This formation of dry ice can lead to incorrect
measurements of the actual pressures present in the corresponding plant components. Ice shooting out of the pipes can also lead to
severe injuries. The expansion of saturated steam below the triple point can also result in small amounts of dry ice, which can form
when (e.g.) releasing pressure in the suction lines.
If the entire refrigeration plant or sections of the plant are shut off for service or maintenance purposes and then depressurised to
atmospheric pressure, before the pressure is dropped below 5.2 bar the section must be checked to ensure that it does not contain
any liquid.
Note: If the pressure drops too rapidly then dry ice can form inside the pipes.
1.
This can cause blockages in plant sections that can release explosively when the pressure increases.
2. The dry ice sublimes at room pressure, which cause more R744 to escape from the plant.
Carbon dioxide does not damage the ozone layer and makes only a minor contribution to the anthropogenic greenhouse effect. It can
therefore be vented into the atmosphere.
DANGER!!! (R744 only)
Danger of R744 suffocation when the auxiliary safety valves are actuated. These vent into the room when activated. When shutting
off plant sections be sure that no refrigerant remains in the shut off section. Check the R744 concentration before entering the room
and while you are in the room.
If only a section of the plant is emptied and the refrigerant is vented into a closed room then the affected room must be adequately
ventilated. The R744 concentration in the room must be regularly checked. However, when the entire system is emptied the
refrigerant must be vented into the open air because the R744 concentration would be unacceptably high in enclosed rooms.
WARNING! : Danger of freezer burns and severe injuries from rapidly escaping refrigerant in the form of liquid or ice. Do not
linger in the vicinity of open pipe work. Wear protective equipment
Maintenance work on the R744 refrigeration plants may only be performed by "authorized persons".
Shutting-off and emptying the entire system or system sections
Shutting-off plant sections
R744 only: Shutting of plant sections via the stop valves results in a pressure increase through the warming effects of the
environment. After a period of time that depends on the ambient temperature, the auxiliary safety valve actuates at 45 bar and
refrigerant is vented into the room. When shutting off plant sections, regularly check the pressure within the shut-off section.
If plant sections must be opened for maintenance and repair work then these sections must be both shut off and also emptied.
Emptying the entire plant or a plant section
R744 only: Emptying all the refrigerant from the plant must occur to the open air to prevent excessively high R744 concentrations
from developing in closed rooms. Venting the refrigerant is not environmentally damaging, since 100 kg of R744 has the same
greenhouse potential as only 30 g of the R404A refrigerant that is normally used.
(H) CFC: Emptying (H) CFC from a plant requires technically correct recycling of the refrigerant for environmental reasons.
Observe the following points when emptying the entire plant:
1.
R744 only: Venting line, connect a 6 mm or 10 mm copper pipe to the filler connection. Mount a 2-way valve rated for 40 bar on the
end of the pipe. Depressurization to normal air pressure must take place at the end of the venting line so that the resulting R744
snow does not block the line.
2. Completely close the shut-off valve in the mail fluid line.
3. Vacuum the plant in the same way as with normal refrigerants. The compressor switches off automatically as the suction pressure
drops.
4. Wait for 10 minutes. If evaporating refrigerant residue causes the suction pressure to increase in this time then the compressors
will automatically start again.
5. Manually vacuum the plant: Switch the compressor to manual mode. Leave switched on until the plant pressure on the suction side
has dropped to a level that the LP pressure monitor automatically switches off the compressor.
6. Switch off the compressor and secure it against being switched on again.
7. Open the shut-off valve in the intake line.
8. Carefully open the 2-way valve at the end of the copper pipe and vent the refrigerant.
9. R744 only: Liquid R744 will escape after the gas has escaped from the pipe. Monitor the plant pressure when venting the
refrigerant.
4/14
10. R744 only: Formation of dry ice can lead to brief clogging of the 2-way valve. The escaping refrigerant will blow the valve free
again.
11. R744 only: Dry ice will form when the plant pressure drops below 5.2 bar. Vent the remaining fluid from the system by heating
using injected pressurized gas or by heating with warm air on the pipe walls or components.
12. R744 only: Repeat this process until the heating no longer results in a significant pressure increase. This then indicates that no
more liquid remains in the system.
13. R744 only: Dry ice will form when the pressure drops below 5.2 bar if any residual liquid remains in the medium pressure reservoir.
In some situations the volume of dry ice can be reduced by adding pressurized gas but it cannot be completely prevented.
14. R744 only: If the reservoir is refilled with gaseous refrigerant after the work has been completed, then the increase in pressure
resulting from this will dissolve the remaining dry ice.
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INSTALLATION
The loading and unloading operations must be performed with adequate handling equipment (forklift, crane, etc.) using possible
lifting points provided for this purpose.
The qualified professional should be certified and will wear individual safety equipment (protective gloves, glasses, safety shoes,
etc.) ; operators will never circulate under the load during lifting operations.
During handling, the operator will ensure a good balance to prevent the equipment from swinging.
Make sure that the equipment or its accessories have not been damaged during shipping and no parts are missing.
If devices are used in a seismic area, then the installer must apply all necessary rules.
The facility’s installation site must be solid enough and horizontal. Make sure that no vibrations are transferred into the
structure.
Enough free space all around the refrigeration equipment should be provided to facilitate maintenance operations.
The heat exchangers must be installed in locations free of any external dust or other pollutants from the neighbourhood which
could obstruct or clog the coils.
If devices are used in a corrosive area (sea side, pollutant gas, etc.), make sure that appropriate anticorrosion protection has been
provided.
Make sure that piping are connected to the appropriate pressurized equipment (EN378-2).
All connecting piping must be correctly supported and clamped.
For the connection of piping, protect sensitive components located around the permanent assemblies to be made.
Before any intervention, the operator must obstruct all the openings of the circuit (+ pressurization under nitrogen).
Discharge piping (outlets of safety valve for example) must be installed in view to protect people and apparatus from leakage of
refrigerant.
Make sure that flexible hoses are not in contact with metal parts.
The products added for thermal and /or acoustic insulation must be neutral with respect to support materials.
The protection devices, piping and accessories must be protected against unfavorable effects from the environment.
Make sure that access and emergency exit ways are not obstructed to comply with the local regulations.
COMMISSIONING
Prior to electrically connect the facility, make sure that the AC power line voltage and frequency ratings correspond to the
indications on the identification plate and the power voltage is within a tolerance of + 10 % with respect to the rated value.
Specific protection is provided according to the neutral system.
Any on-site wiring must comply with the legal standards in force in the country of installation (including grounding).
Before turning on a device, make sure that :
- the electric connections have been correctly made
- the clamping screws of the various terminals are correctly tightened.
OPERATING
Do not use the refrigeration equipment or components for any utilization other than that for which it is designed.
Comply with the special manufacturers’ recommendations contained in the manufacturers’ operating instructions.
It is strictly prohibited while the device is running to remove the guards and paneling provided by the manufacturer to protect
the user and ensure his safety.
When operating, surface temperatures above 60°C and /or below 0°C may be reached. During any servicing operation, the
personnel should be extremely careful while working on the device.
Profroid is not informed to real use of partly completed machines ; their integrations and use must comply to Machines Directive
and recommendations of this operating instructions.
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MAINTENANCE
The device must be checked and inspected into service, regularly, by a qualified and approved personal, following rules.
The device will be subject to preventive maintenance (EN 378) :
- external visual inspection of device,
- checks of device during running,
- checks of device corrosion.
Before working on pressurized components, shut down the facility and wait until pressure and temperature are not dangerous.
Before removing the guards and paneling, turn off the device. Set it aside and make sure that no power is present.
Do not use piping to access on the equipment or to store something on the equipment.
The replacement of a safety valve must be made by the same brand of the original one.
If there is modification of type and /or brand, then the professional in charge of the replacement will do a calculation sheet
following EN 13136 and /or ask Profroid some elements.
Handle regularly the device valves in view to avoid theirs blocking on.
If a personal in charge of maintenance closed a blocked valve, this personal will must avoid the possible increase of
pressure in the part of device which is isolated.
The periodic technical checks must be made following frequencies determined by standards, sound engineering
practice, end user and installer.
Report periodic checks and analyze the datas. In case of abnormalities or inconsistencies, determine the cause and correct it.
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1-
DESCRIPTION – OPERATIONS
GENERAL DESCRIPTION
•
The Hybrid COMBICOOL racks are composed of one MT R134a Rack and one LT CO2 Cascade Rack staked together , and the CO2
receiver and the OC2 -R134a Condensers
With :
2 to 4 semi-hermetic Ecoline® Bitzer compressors for the medium temperature R134a rack
•
1 to 3 semi-hermetic Octagon® BITZER « SL » range compressors for the CO2 Low temperature Rack
•
1 or 2 plate heat exchangers for function evapo-condenser of the cascade
•
•
•
•
1 or 2 electronic stepper motor expansion valve for the cascade control
1 horizontal isolated and integrated CO2 liquid receiver with liquid line for the CO2 LT rack
1 liquid receiver R134a with its line liquid for the R134a MT rack (delivered separate)
An electrical cabinet mounted at the end of the frame , for Rack and condenser Control and power supply
The two machines are indisociable, the CO2 cascade machine low temperature can work only if at least one positive machine compressor
is running.
2-
HANDLING - TRANSPORTATION
Power plants are equipped with lifting holes in upper part of the chassis for lifting or handling by crane. In this case use a suitable
rudder either meet a maximum angle of 15 ° between the slings.
Do not use the lifting holes of the Cabinet for the handling of the complete rack.
Ground handling can be achieved using forklift or pallet truck passing the fork under the lower beams. Available passage height: 75 mm.
The machine will be delivered tent under shrink polyane without additional pallet or wood parts.
When reception of the machine, ensure that it has been received neither damage nor component loss during transport. In contrary,
issuing case corresponding reserves with the transportation company.
3-
INSTALLATION
INSTALLATION RECOMMENDATIONS
The power pack is positioned on 4 or 6 Silent blocs depending on the model. It must be exactly level in order to avoid creating an
accumulation of oil at the lowest point, in the suction and discharge pipes, or causing vibrations.
Sufficient space should be left around the unit to allow maintenance.
Silent blocs are adjustable in height, allowing them to be adjusted precisely to make them level.
The power pack must be kept in a water-free environment.
REFRIGERATION NETWORK CONNECTION
General information
BEFORE ANY WORK IS DONE ON THE REFRIGERATION CIRCUIT, THE HOLDING CHARGE MUST BE REMOVED.
The piping used (copper or steel) must be of refrigeration quality in accordance with PED 97/23/EC.
All piping must be correctly supported and fixed and should in no case be allowed to restrict the piping of the power pack.
Interfaces for connecting upstream of the condenser, and downstream of the receiver are formed by copper tube soldered on
valves (diameters according to Rack Characteristics).
8/14
Rack Installation :
Connection to be done are :
For the R134 side :
•
Common discharge line to condenser (Copper)
•
Common suction line coming from Mt consumers (Copper)
For the CO2 side (upper part of the machine ):
•
Liquide CO2 outlet pipe toward LT consumers (Copper)
•
Common suction line coming from LT consumers (Copper)
•
The safety valve(s) must be connected to the outside of the machine room with no shut-off valve The connection is made onsite by the installer
.
Installation of a liquid station provided separately.
As a standard feature, the liquid receiver (provided separately from the power pack) is fitted with configurations of accessories
as follows (forming a liquid station):
One or several drier filters, a liquid sight glass, a level indicator, one or two safety valves (depending on capacity), input/output
shut-off valves.
The pressurised receivers are provided with a temporary charge of neutral gas (nitrogen or dry air) which should be removed
before any operation (connection by welding).
To eliminate this neutral gas totally, the whole installation should be put into vacuum.
The safety valve(s) must be connected to the outside of the machine room with no shut-off valve.
The connection is made on-site by the installer.
The receiver should be placed above the condensers.
The upstream/downstream connection interfaces of the receiver are formed by copper pipe links welded onto the shut-off valves
(diameters according to the size of the power pack).
The liquid station “input” is situated in the upper part.
The liquid station “output” is situated in the lower part after any accessories such as the sight glass or drier.
Important: The receiver must be strongly screwed on ground (4 points on the base plate of receiver).
EXAMPLE:
Safety valve
Inlet
Base plate
for screwing
on ground
Outlet
9/14
ELECTRICAL CONNECTIONS
General information
The machine is designed in accordance with EN60204-1.
All cabling on site must conform to the legal standards in force in the relevant countries and to EN60204-1.
Except for special operation, the nominal current must be:
power circuit: 400V/3/50Hz + Earth
control circuit: 230V/1/50Hz (pressure switches – crankcase heaters).
Electrical motor wiring
This motors are Direct On Line starting.
The instructions shown on the compressor should, however, be respected. See Bitzer instructions.
The compressor motors are fitted with an electronic module allowing a maximum of 6 start-ups per hour.
Important: the maximum imbalance between phases is 2% in voltage and 10% in current per motor.
Variable speed drive on compressors and Fan motors
The Rack is equipped with Variable speed drives housed in ventilated electrical cabinet
It is necessary to ensure the proper functioning of these ventilation and to avoid any risk of obstruction.
Electrical connections of the drives and compressors or fans is done using shields cables to guarantee EMC compatibility. In the
case of intervention on them, it is necessary to ensure that the connexions of shielding, groundings etc are properly done, to
maintain this compatibility with EMC.
Important:
Variable frequency drives can cause on some installations of vibration on the pipes, related to installation resonance. It belongs to
the installer to remove these harmful frequencies by setting prohibiting frequencies. This setting cannot be made from factory
due to installation configuration
On residential area , In is necessary to add an RFI filter (not included in the present scope)
ADDITIONAL SAFETY CONTROLS
Safety Features
The safety switches fitted to the compressors (HP/LP pressure switches, kriwan, discharge temperature controller) must cut off
the compressor instantaneously.
Crankcase heaters
These run when the compressor is shut off.
AUTOMATIC MECHANICAL DEVICES
As the equipment is delivered with connected electrical cabinet , it is mandatory to refer to the electrical wiring diagram and the
PLC instruction and operating documentation.
.
10/14
4-
START-UP OPERATION
PRELIMINARY CHECKS AND OPERATIONS
General information
Ensure that all the threads are fully tightened on connection flanges, flexible connections and cables as jolting during transport
could cause screws and bolts to loosen.
Check also, for same reasons, if there are any breaks in the piping.
Ensure that the flexible connections are not in contact with metal parts. Vibrations from the compressor can cause wear in these
until they rupture at the point of friction.
Before starting up a machine with pressurized tanks, all service valves must first be opened upstream and downstream and all
external valves closed..
Leaks testing
Pressurize the whole system, including the compressors, using a neutral gas (Nitrogen) with a tracer at a minimum pressure of 10
bars and at a maximum pressure below 20.5 bars, isolating the LP (low pressure) switches.
Important: If the LP (low pressure) circuit is fitted with a safety valve (e.g.: on the suction accumulator) the test pressure on that
part of the circuit should be approx. 20% below the operating pressure of this valve.
Thorough leakage detection using electronic detector should be carried out on the unit.
After these tests, the gas must be removed. Fit the drier cartridges in their casing.
Dehydration of circuits
This operation must be carried out with all valves open (including solenoid valves) with connection to a vacuum pump of the low
pressure side and of the high pressure side.
The quality of drying should not be judged by the speed at which the level of vacuum is reached but on the effective time it
is held (24 hours at 0.7 mbar is a good standard).
The total increase in pressure during that period should not be more than 2.6 mbar. The residual moisture in the system should be
less than 20ppm.
When the installation is under vacuum, an insulation check of the motor should not be carried out nor should the compressors be
started before at least 1 bar of fluid pressure is reintroduced.
This is to prevent motor windings damage.
Particularity of CO2: The oils used are strongly hygroscopic, it is necessary to have a very careful vacuum draw, particularly well to
verify the absence of degassing of oil end drawing (visible through oil sight glass no bubble should be visible)
Oil Level Check
Oil levels should never exceed the Bitzer recommendations
see also stickers directed sticked at compressor crankcase.
Oils
-
The compressor manufacturer recommendations should be followed.
The use of colorants or UV tracers as leak detectors in the oil, is not allowed.
RECOMMENDED OILS :
BSE60K (for compressor range SL) or BSE85K (for compressor range HC) on the LT CO2 Rack
BSE32 or EAL 32 pour the MT 134a Rack (Ecoline compressors)
If any other oil is to be used, we would advise contacting PROFROID or the compressor manufacturers.
Energise the crankcase heaters
Switch on crankcase heaters 24 hours before start-up.
Refrigerant Fluid Charge
•
R134a MT Rack :
Filling in liquid phase is possible when installation is still under vacuum throw the filling valve placed on the filter drier cover.
•
Partie R744 Centrale négative :
R744 cascade system is operating in combination with a refrigeration plant for medium temperature cooling. This plant should be
already in operation during startup of the R744 system and must have attained stable operating conditions.
Due to high requirements for residual moisture, R744 must be charged via a filter drier.
It is imperative to charge in liquid phase when the installation is under vacuum and this up to have more than 6 bar in the circuit
(R744 triple point : 5,2 bar). Close compressor suction and discharge valves and continue to fill in gas up to approximately 20 bar.
11/14
Then you can fill in liquid through the charging valve provided on the liquid receiver (depending on models) or through charging valve
located at filter drier (depending models).
Start the charging process not below 35-40°C oil temperature.
Continue Charging operation until covering the whole low level sight glass from the CO2 liquid receiver, all consumers running (means
all electronic expansion valves 100% open)
Pre-Setting And Checking of Safety Systems
Test the oil pressure switches
Check default timer
Check the actual cut-off if oil level default.
HP pressure switches
Pre-set the HP pressure switches and test manually.
Maximum set : high pressure limit of compressor (check before value of max. Operating pressure)
LP pressure switches
Pre-set the LP (Low Pressure) pressure switches and test manually. Do not set these below 6 bar (R744 triple point : 5,2 bar)
Start-up of compressors
First of all, check that medium temperature rack is working correctly.
- Open compressor discharge valve
-Open suction valve partially, then open these valves slowly as the suction pressure decreases.
- Place an ammeter on one phase of the compressor
- Close the power circuit-breaker or the fan motor cut-outs.
- Start up compressor by switching the on/off switch to on.
The current increases to maximum and must decrease very rapidly. If this does not happen, stop the compressor to check and
find the fault.
Repeat these operations for each compressor.
Remainder of charge
Fill up with the remainder very quickly.
An incomplete charge of fluid will cause considerable superheat and so abnormally high discharge temperatures.
OPERATING CHECKS
Shortly after start-up, the operating conditions of the equipment must be checked.
The compressor must operate within its acceptable limits
Check on each compressor (with the others shut down):
.
Discharge pressure
.
Oil level
.
Measure suction temperature for the stage LP and HP
.
Measure discharge temperature
.
Measure oil temperature on entry into the compressor
- The crankcase temperature must not fall below 30°/35°C
- The pressure in the oil vessel must be 3,5 bar bar greater than the suction pressure.
- Suction superheat should be between 15K and 20 K. However a smaller superheat is acceptable (down to 10K) if oil temperature and
discharge temperature stay in the acceptable values.
Very important:
There is no need to add oil over and above the required quantity during start-up.
Excess oil generally leads to oil slugs on the unit which causes damage to the compressors (broken valves or gaskets).
5-
MAINTENANCE
Every month, check:
- Safety cut-off points of HP/LP safety pressure switches
- Pressures and temperatures in each compressor.
- Oil levels
- Moisture in the circuits (through sight-glass or by analyzing oil)
- The state of all flexible pipes
- Check for leaks in the refrigeration circuit.
Every year in addition to the monthly checks:
- Carry out an analysis of the oil
Instructions or recommendations appearing in the various technical advice notes and manufacturer's service manuals should be
followed precisely. Please contact our Technical Department for any additional information.
12/14
6-
TROUBLESHOOTING
Examples of faults and solutions
FAULT
PROBABLE CAUSE
ACTION REQUIRED
1. Suction
Temperature too
high
2. Suction
Temperature too
low
3. Suction
Pressure too low
Too much suction gas superheat
(above 20K)
Examine and adjust the expansion valves in the
evaporators (especially the MOP).
Liquid in the suction line.
Superheat
sensor
loose
or
incorrectly
positioned.
Too much oil in evaporators.
Filter in the liquid line clogged.
Suction filter blocked.
Too much superheat of suction gas.
Expansion valve blocked when in closed position.
Adjust expansion valves.
Check if sensor is in contact with the suction line
and if it is positioned correctly
Drain oil from evaporators.
Examine and clean filters in liquid line.
Check suction filter.
Adjust expansion valves.
De-ice expansion valve using warm rags. If no
improvement, change the expansion valve.
Check wiring and coil – replace if necessary
Charge the installation with refrigerant.
Problem with solenoid valve in the liquid line.
Installation insufficiently charged.
4. Compressor cuts See point 3
Low pressure safety switch set too high.
in and out too
often on LP safety Evaporator iced over or frozen water present in
switch
the distributor.
Restart after defrost.
5. Suction
Pressure too high Compression problems
Condenser malfunction
6. Condenser
Pressure too high
Not enough liquid on expansion valve from the
cascade condesnser
Installation flooded
7. Condenser
pressure too low
8. Discharge
Temperature too
high
9. Oil temperature
too high
10. Oil
temperature too
low
11. Capacity too
great
12. Insufficient
Capacity
Adjust pressure safety switch.
Clean or defrost evaporator.
Wait for confirmation
Check valves and gaskets
Check efficient function of HP R134a rack
Check if no problem with expended R134a
Control superheat and adjust expension valve
Drain liquid into receiver
Air or non-condensable gas in the HP circuit
Not enough airflow on air cooled condenser
Start of condenser fan not well adjusted
Suction pressure too low at R134a rack
Let air out at highest point.
Clean , Check running of condenser fans
Adjust
Check R134a rack operating conditions
Too much superheat on suction.
Internal by-pass.
Adjust the expansion valves.
Check valves and joints.
Superheat on suction too great.
Valve problems.
Check and adjust expansion
valves
Check pressures. If necessary, adjust valves and
gaskets.
Replace heater
Adjust expansion valve
Crankcase heater out of order.
Oil return saturated in liquid refrigerant
Suction superheat too low
Problem with control system or other automatic Replace, repair or re-set
devices.
Problem with control system or other automatic Replace, repair or re-set.
devices
13/14
FAULT
13. Oil foams
heavily after
stoppage
PROBABLE CAUSE
Expansion valve (fluid in suction line).
ACTION REQUIRED
Check expansion valve.
Sensor incorrectly positioned
Check sensor position
Crankcase heater out of order
Replace heater
During start-up some of the oil is released into
14. Oil level
dropping in oil tank the unit.
Separator float out of order or orifice blocked.
Degassing valve blocked shut.
Level controller blocked open
15. Compressor
trips when oil
pressure switch is
pressed
some of the oil is in the circuit and has difficulty
returning to the tank.
Replace or clean.
Repair or replace
Check and replace
Drain excess oil from unit.
Too much oil in tank.
Check oil return conditions (superheat, slope,
suction accumulator., display cabinet, piping).
Fraction and stagger unit defrosts.
Oil level regulator out of order or connection Check if working
problem.
Tighten connections.
Replace oil level regulator if necessary.
Oil pump out of order
Not enough oil pressure
Oil suction strainer pluged
Compressor sight glass level too low.
15. Abnormal
Noise in
Compressor
(*)
17. The
Compressor Motor
does not start
18. The
Compressor works
continuously
Bolts loose.
Broken connecting-rod
Liquid in suction line
Sensor loose or incorrectly positioned.
Emulsion in oil crankcase
Oil pressure switch cuts out after time delay.
Low pressure switch cuts out.
High pressure switch cuts out.
Fuses burnt out
Anti-short cycle time delay relay is in operation
Thermal relay or KRIWAN cut out
Main circuit breaker switch open.
Control system or other automatic device fault.
Installation insufficiently charged
Evaporators blocked or ice presence
Check that the vessel contains oil
Check the oil supply to the level controller
Check the float is working (replace if necessary).
Tighten bolts
Do not re-start compressor
Check and re-set the expansion valves.
Check that the liquid solenoid valves do not remain
open when machine stops.
Check sensor position
Incorrect lubrication. See paragraphs 13 and 10.
See paragraphs 9 - 10 - 11 - 12.
See paragraph 3.
See paragraph 5.
Check the cause and change fuses
Wait
Check cause of overload.
Close circuit-breaker.
See paragraphs 13 and 14.
Charge installation with refrigerant
Clean and defrost evaporators
(*)If there is an abnormal noise in the compressor, switch off the compressor. Find
the cause of the noise and remedy before re-starting
Manufactured in France by PROFROID CARRIER S.C.S
178, rue du Fauge - ZI Les Paluds - B.P. 1152 - 13782 Aubagne Cedex - France
International : Tel. (33) 4 42 18 05 00 - Fax (33) 4 42 18 05 02
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