Carrier 61CW-Z Manual

INSTALLATION, OPERATION AND
MAINTENANCE INSTRUCTIONS
Original document
Heat pump operating manual
61CW-Z

2
1 - GENERAL INFORMATION............................................................................................................................................................3
2 - SAFETY .........................................................................................................................................................................................4
2.1 - Qualication of personnel..........................................................................................................................................................4
2.2 - Risks from failure to observe the safety information .................................................................................................................4
2.3 - Safety information for the operator............................................................................................................................................4
2.4 - Unauthorised modications.......................................................................................................................................................4
2.5 - Intended use..............................................................................................................................................................................4
3 - DESCRIPTION...............................................................................................................................................................................5
3.1 - Function.....................................................................................................................................................................................5
3.2 - Layout of appliance types 61CW-Z ...........................................................................................................................................5
3.3 - Pipework....................................................................................................................................................................................6
3.4 - Safety equipment ......................................................................................................................................................................7
3.5 - Guarantee .................................................................................................................................................................................7
4 - INSTALLATION .............................................................................................................................................................................8
4.1 - Delivery .....................................................................................................................................................................................8
4.2 - Transport ...................................................................................................................................................................................8
4.3 - Installation location....................................................................................................................................................................8
4.4 - Preparation................................................................................................................................................................................8
4.5 - Heating connection (WNA)........................................................................................................................................................8
4.6 - Source energy connection (WQA).............................................................................................................................................9
4.7 - Electrical connection ............................................................................................................................................................... 11
4.8 - Fitting sensor leads .................................................................................................................................................................12
5 - COMMISSIONING .......................................................................................................................................................................13
6 - OPERATION ................................................................................................................................................................................14
6.1 - Restarting................................................................................................................................................................................14
6.2 - Control.....................................................................................................................................................................................14
6.3 - Safety functions.......................................................................................................................................................................16
7 - MAINTENANCE...........................................................................................................................................................................17
7.1 - Service work............................................................................................................................................................................17
7.2 - Inspection by the operator.......................................................................................................................................................17
7.3 - Customer service ....................................................................................................................................................................18
8 - TROUBLESHOOTING.................................................................................................................................................................19
8.1 - Alarm messages on the touchscreen ......................................................................................................................................19
8.2 - General troubleshooting..........................................................................................................................................................19
9 - DISPOSAL...................................................................................................................................................................................21
10 - APPENDIX ................................................................................................................................................................................. 22
The illustrations in this document are for illustrative purposes only and not part of any o󰀨er for sale or contract. The manufacturer reserves the right to change the design
at any time without notice.
CONTENTS

3
1 - GENERAL INFORMATION
The language of the original operating manual is German. This manual in any other language is a translation of the original operating
manual.
Close observation of this document is a prerequisite for the intended use and correct operation of the product.
The operating manual corresponds to the product version and the safety regulations and standards applicable at the time of printing.
A copy of the EC declaration of conformity is part of this operating manual. Any modication of the machine not authorised by the
manufacturer (CARRIER) or non-compliance with the product or personnel safety instructions in the operating manual will invalidate
this declaration.
BEFORE INSTALLING AND COMMISSIONING THE HEAT PUMP, READ THIS OPERATING MANUAL IN FULL.

4
2 - SAFETY
These operating instructions contain basic information that must
be observed during installation, operation and maintenance. It
must therefore be read by the installer and relevant specialist
personnel/operator prior to installation and commissioning.
Keywords:
DANGER!
Immediately dangerous situation. Failure to observe this
information will result in death or serious injury.
WARNING!
The user may suer (serious) injuries. “WARNING” includes
the likelihood of (serious) injuries if the information is not
observed.
CAUTION!
There is a risk of damage to the product or the system.
“CAUTION” indicates possible product damage if the
information is not observed.
2.1 - Qualication of personnel
The personnel designated to install, operate and maintain this
equipment must have the appropriate qualications for such work.
The operator must determine the relevant areas of responsibility
and ensure the supervision of personnel. If the personnel do not
have the required knowledge, they must be trained and briefed.
If required, this can be carried out by the product manufacturer
on behalf of the operator.
2.2 - Risks from failure to observe the safety
information
Failure to observe the safety information may result in a danger
to individuals, the environment or the system. Failure to observe
the safety information results in the loss of any claims for damages.
In particular, failure to observe such information can result in the
following risks:
■ Danger to individuals due to escaping hot water/uid
■ Danger to individuals due to electrical current
■ Danger of environmental pollution due to leaking uids
■Damage to the system or system components through
mechanical inuences
2.3 - Safety information for the operator
Operators may be required to use PPE (personal protective
equipment) such as: Ear protections, protective clothing (gloves,
safety glasses, safety shoes, etc.. list not exhaustive). Is therefore
asked to perform risk assessment and follow local regulations.
The safety information listed in this operating manual must be
observed, as must all applicable national regulations on accident
prevention and any in-house occupational, operational or safety
regulations issued by the operator.
This appliance is not intended to be used by persons (including
children) with limited physical, sensory or mental capacities.
Persons lacking appropriate experience and/or knowledge may
not use this appliance unless they are supervised by a person
responsible for their safety or have been comprehensively
instructed or briefed in the correct use of the appliance by such a
person.
Children must be supervised to ensure that they never play with
the appliance.
CAUTION! Standing and climbing on the heat pump can lead
to damage to various components and is not permitted.
The refrigerant lines and heat pump components must not be
damaged in any way.
The insulation of lines and the heat exchangers in the heat pump
must not be removed or damaged.
Never operate any valves on the machine!
To safeguard the intended use, no temperature sensors, pressure
sensors or cables must be removed or damaged. In the event of
damage, please contact CARRIER.
Never poke any objects into parts of the heat pump or insert or
reconnect anything.
Observe and comply with the details in the safety datasheets
supplied!
If leakages occur, immediately stop the pressurised system and
contact CARRIER.
Generally keep easily ammable materials away from the system.
DANGER! When working on electrical equipment, there is a
risk to life from electric shock.
Before any work on electrical equipment, isolate it from the
power supply and secure against unintentional reconnection.
Observe the ve safety rules of electrical engineering.
DANGER! The control cabinet must remain closed while the
heat pump is running!
The key to the control cabinet must be kept separately.
WARNING! During operation and subsequent stops, the
surfaces of the heat pump are hot. Risk of burns on contact
with heat pump components!
Observe safety and environmental requirements (for example,
see: EN 378).
2.4 - Unauthorised modications
Unauthorised modications and production of spare parts present
a risk to the system and personnel and invalidate the manufacturer’s
safety declarations. Modifications to the product are only
permissible following consultation with the manufacturer. For spare
parts, please contact CARRIER. Use of other parts voids the
liability for any consequential losses.
2.5 - Intended use
Heat pumps in the 61CW-Z series take the energy of a system
with a low temperature level, increase the temperature level using
mechanical work and transfer it, along with the drive energy
applied, to a heating system. The low temperature level system
can also be used as a cooling circuit.
There are many possible areas of application in industry, always
keeping in mind the machine’s application limits, in particular those
of the shell and tube heat exchangers (Table 1) and the compressor
(appendix). The heat pump must not be operated outside these
limits.

5
3 - DESCRIPTION
3.1 - Function
Heat pumps of types 61CW-Z are compact units for indoor installation.
Heat is drawn from a water or brine circuit at 8 to 20°C (e.g. process coolant, return coolant, etc.). The heat pumps can be used to
provide heating and process heat up to 92 °C.
3.2 - Layout of appliance types 61CW-Z
Fig. 1: Basic principle of a heat pump
EVAPORATOR
CONDENSER
ECO-HX
mc+ mi
mc+ mi
Increased heat transfer through
higher mass ow rate.
mc
mi
mc
Pi
P
h
mi
3.2.1 - Thermodynamic circuit
This consists of:
Shell and tube heat exchanger as evaporator, compressor, shell
and tube heat exchanger as condenser, plate heat exchanger as
oil cooler, plate heat exchanger as economiser, oil separator, oil
filter, drier, electronically controlled expansion valves, high
pressure and low pressure controller, solenoid valves, high and
low pressure sensors for electronic monitoring of application limits,
chlorine-free refrigerant and special oil for the compressor/oil
separator.
3.2.2 - Compressor
CARRIER high-temperature industrial heat pumps of series c2
are equipped with a semi-hermetic screw compressor. Due to an
asymmetrical high performance prole, these rotary displacement
machines achieve maximum e󰀩ciencies. Lacking any oscillating
components, they operate with very low vibrations.
The roller bearings are specially designed for high temperatures.
The excellently designed cooling system of the motor allows
operation in a very wide application range.
Within the permissible application limits, output control can be
implemented as follows and depends on the selected or ordered
conguration:
■ Three-position control 50/75/100 %
■ Continuous between 50 and 100 %
Subject to output demand, a hydraulically operated output slider
varies the refrigerant ow through the compressor screw. This
means of control operates via solenoid valves that are ange
mounted on the compressor, and is carried out subject to an
algorithm implemented in a standalone controller.
The application limits of the heat pump are given in the appendix
(section 10).
To ensure a long compressor service life, the heat pump must
be kept running for at least 10 minutes and be idle for at least 6
minutes.
3.2.3 - Frame
The heat pump components are mounted on a solid frame, partly
self-supporting on the shell and tube heat exchangers.
3.2.4 - Sound insulating enclosure
To reduce sound emissions, a sound insulating enclosure can be
ordered as an option. Depending on the compressor type, this
can achieve a sound pressure level reduction of about 10 to 15
dB(A).
The control cabinet is delivered mounted to the heat pump as
standard. However, prior to tting the sound insulating enclosure,
carefully remove the heat pump control cabinet and place it on
the substructure supplied by CARRIER (see dimensions sheet).
The control cabinet and the electric cables must not be damaged.
The enclosure is designed for easy handling and uncomplicated
tting. It consists of several dirt repellent aluminium sheets with
sound insulating material, which are joined together with quick-
action fasteners. For sound insulation of the heat source
connections (WQ) and heat consumer connections (WN), tailored
aluminium sheets are supplied. To allow maintenance and
servicing, certain panels are not load bearing and can therefore
be removed individually.

6
A fan is provided to lower the temperature inside the sound
insulating enclosure. This fan must be installed by the client and
connected to a 230 V power supply. To improve e󰀩ciency, it makes
sense to t a thermostat (not part of the standard delivery) for
starting and stopping the fans. The thermostat should be installed
inside the sound insulating enclosure and should start the fan at
temperatures ≥30°C. Assembly instructions are supplied with the
sound insulating enclosure.
Assembly requires 2 persons (in particular of the roof elements).
Unless ordered separately, the sound insulating enclosure is not
installed by CARRIER.
Because the sound insulating enclosure rests on the oor, the
oor around the heat pump must be level and must not contain
elements such as pipes, proles, etc. in the contact area of the
soundproong enclosure.
The pipes to the heat exchanger connections of the heat pump
must be routed in a straight line. Never use bends inside the sound
insulating enclosure. The minimum length for a straight pipe
section is given in the “Dimensions sheet with sound insulating
enclosure”, which is available from CARRIER on request. Ensure
that no pipes, proles, etc., interfere with the sound insulating
enclosure.
3.3 - Pipework
3.3.1 - General
3.3.1.1 - Refrigerant lines
The following refrigerant lines are installed inside the heat pump:
■ Suction gas line (SL)
■ Pressure line (DL)
■ Liquid line (FL)
■ Economiser line (EL)
■ Oil line (ÖL)
These are made from copper or steel, depending on their diameter
and application. The lines are intended only for conveying the
refrigerant within the heat pump.
3.3.2 - Operating media
The pipelines listed under 3.4.1.1 are lled with the uid indicated
on the respective type plate and must only be lled with this uid.
Use of any other substance immediately voids the CARRIER
warranty and any claims for damage.
3.3.3 - Application range
The required ambient conditions are described in section 4.3
(installation location).
The maximum pressure as well as the maximum and minimum
temperature are also specied on the type plate and must never
be exceeded.
3.3.4 - Mechanical stress
Beyond the intended use, the installed lines must not be exposed
to any additional mechanical or thermal loads.
Mechanical loads can result in pipework deformation, stress cracks
in pipe components and joints, or pipes pulling o󰀨, resulting in
leakages or even a total failure of the heat pump.
The above pipes must not be welded or brazed without approval
from CARRIER. Any welding or brazing work by third parties voids
CARRIER’s warranty as well as the CE Declaration of Conformity.
No mechanical work must be carried out on the above pipes
without approval from CARRIER. Any mechanical work by third
parties voids CARRIER’s warranty as well as the CE Declaration
of Conformity.
Screws designed to attach the refrigerant lines to the heat pump
must not be undone.
Screws in the lter dryer cover must not be undone.
Shut-o󰀨 valves must not be operated.
Inserts in Schrader valves must not be operated or unscrewed.
Only CARRIER customer service may remove or dismantle
pipework. Removal by third parties is not permissible and
immediately voids CARRIER’s warranty.
In the event of leakage, please contact CARRIER immediately.
Leakages may only be repaired by CARRIER customer service.
DANGER! Escaping refrigerant can cause severe burns and
oxygen displacement!
CAUTION! Escaping refrigerant can result in a total failure of
the heat pump.
3.3.5 - Insulation
Lines are tted with thermal insulation. This must not be damaged.
Damaged insulation can result in excessive heat transfer (heat
loss) to the environment, reduction of the COP (coe󰀩cient of
performance) and condensate formation on cold pipes, resulting
in corrosion.
The insulation is classied D-s3, d0 according to EN 13501-1.
3 - DESCRIPTION

7
3 - DESCRIPTION
3.4 - Safety equipment
CARRIER high temperature heat pumps of series c2 are equipped
with the following safety features:
■ Refrigerant circuit safety valves
■ High and low pressure sensors for electronic monitoring of the
operating state
■ Mechanical pressure switches
■ Hot gas sensor/compressor outlet temperature monitoring
■ Di󰀨erential pressure switch for monitoring the water/brine ow
rate at the evaporator
■ Phase and eld rotation monitoring
■ Thermal motor winding protection
■Oil temperature limiter
■ Oil level limiter at the compressor
■Motor overload relay for pumps in external heat source systems
(WQA) and heat sink systems (WNA) (optional)
■Motor overload relay for compressor windings (only on versions
without soft starter)
3.5 - Guarantee
All CARRIER heat pumps are covered by a guarantee of 24
months, provided the installation and operating conditions are
adhered to and the system datasheets have been completed. The
system design and layout must comply with the applicable
engineering standards. Appropriate ow rates in the heat source
and heat sink must be ensured. The water quality of the heat
transfer media must always be ensured. In the case of heat
sources for brine (geothermal collectors, ditch collectors or
geothermal probes), the system installer is responsible for sizing
the extraction surface or capacity, taking account of local
conditions. No liability is accepted for any heat pump faults
resulting from the heat source system (WQA), the heating system
(heat sink system, WNA), incorrect settings of the control elements
or force majeure (lightning strike, ooding, etc.).
The heat pump must be commissioned by CARRIER customer
service. Correct installation and function of the WNA, WQA and
electrical installation must be ensured by the system installer.
Otherwise any guarantee or warranty is invalid.
BEFORE INSTALLING AND COMMISSIONING THE HEAT
PUMP, READ THESE OPERATING INSTRUCTIONS IN FULL.
Additional work necessary to ret incorrectly positioned or tted
devices will be invoiced in the case of work carried out under
guarantee.

8
4 - INSTALLATION
4.1 - Delivery
The heat pump is delivered in the packaging specied when
ordering.
As standard, the heat pump is mounted on a pallet and protected
against light rain and water splashes with a protective lm.
Each industrial heat pump leaves our factory in fault-free and fully
working condition and is charged with refrigerant and lled with
machine oil. On delivery of the system, customers must check it
for damage, completeness and compliance with the order, and
ensure the data on the type plate is correct. The type plate is
located on the side of the heat pump control cabinet.
The carrier must be immediately notied of any damage, which
must also be indicated on the delivery note. The customer is
advised to complete a report about any incurred damage, if
possible with photographic evidence, and contact CARRIER.
For further information, see our terms and conditions of sale and
delivery.
Please report any transport damage immediately on receipt.
4.2 - Transport
DANGER! The heat pump must be lifted only at the points
provided. A lifting diagram is included in the appendix (section
10).
CAUTION! The heat pump must be lifted and moved only by
qualied personnel. Before moving the heat pump, check its
dimensions and weight to be able to select a suitable lifting
system.
CAUTION! Avoid impact as far as possible so as not to
damage the heat pump. Before installing the heat pump, make
sure that the free spaces inside the building along the
transport route are large enough for the heat pump and are
not blocked by objects.
CAUTION! The heat pump must remain in its packaging for
transport up to the time of its installation or interim storage
and must be stored in a dry, frost-free place and protected
against mechanical damage. Over short distances, you may
transport the secured appliance carefully at an angle of up
to 30°. Should its transport require greater angles of
inclination, consult CARRIER in advance. During both
transport and storage, ambient temperatures from -15 °C to
+50 °C are permissible.
CAUTION! The standard packaging does not provide
protection against the weather or sea water.
Transport damage can be accepted only if reported to the
haulier immediately after unloading.
CAUTION! If the heat pump is transported again at a later
date, it must be protected with suitable transport packaging.
4.3 - Installation location
The requirements for the installation site are detailed in European
standard EN378 (for instance part 3 section 5) and are the
responsibility of the system operator. The room air temperature
in the heat pump installation room must not exceed 30°C. The
appliance must be installed on an even, horizontal surface. The
heat pump must be installed level. Choose a location for the
appliance where it can be easily operated and where CARRIER
customer service personnel have good access to it. The required
minimum clearances around the heat pump are specied in the
layout drawing in the appendix (section 10).
CAUTION! Cables and pipework of the heat pump must not
be subjected to external forces at any time.
The standard delivery includes ruber-metal anti-vibration mounts,
onto which the heat pump should be mounted. Secure the heat
pump to these anti-vibration mounts with screws.
The heat pump/rubber:metal anti-vibration mounts must be bolted
to the oor.
The heat pump must be mounted on the oor such that no
vibrations are transmitted to the building. Reverberant (sound-
reecting) rooms can increase the perceived noise emission. There
is always a possibility of transmitting vibrations/noise to adjacent
rooms, which should be considered when engineering the
installation.
Noise generation can vary with changing operating conditions and
performance requirements. Sound emissions also increase
proportionately with heat pump size and output.
Check for the need for machine room ventilation, e.g. according
to EN 378 and/or applicable refrigeration system regulations, and
install ventilation as required. Observe safety and environmental
requirements (for example, see EN 378).
4.4 - Preparation
Install the heat pump only when all welding and brazing work has
been completed, all threaded connections have been made and,
if necessary, the pipework has been ushed. Dirt can damage the
heat exchangers.
4.5 - Heating connection (WNA)
It is the system installer’s responsibility to size and route the heat
sink system within the CARRIER guidelines.
The system installer must size and install all components required
for the hydraulic circuit (e.g. safety valve, diaphragm expansion
vessel, air vent valve, etc.).
WARNING! The upper pressure limit and maximum
temperatures of the heat pump condenser given in the
machine data (see appendix) must not be exceeded at any
time. This applies regardless of whether or not the heat pump
is running.
To ensure this, install pressure relief devices in the pipework and
service/check them regularly. Ensure that there are no shut-o󰀨
valves in the pipework between the heat pump connection and
the next pressure relief devices.

9
4 - INSTALLATION
In addition to the mass ow to be dumped by the operator in an
emergency, the pressure relief device must additionally be able
to dump a mass ow corresponding to the required minimum
refrigerant blow-down capacity Qmd (see safety valve calculation
in section 10).
The heat pump must be operated only within the permissible
limits of use (see appendix). The system installer/operator must
ensure that the limits of use are maintained.
When selecting and sizing lines, observe the applicable general
and national standards, conditions and guidelines. The latest
applicable engineering standards must be taken into account and
observed.
We recommend hydraulic separation of the heat pump and heat
distribution network/heat consumers. This separation can be
achieved with a separate heating circuit connected to a low loss
header or bu󰀨er tank. On the heating side (condenser), ensure a
su󰀩ciently large bu󰀨er volume – at least 15 litres per kW of heating
output. A smaller bu󰀨er tank can only be used in exceptional cases
and at the user’s own risk if the energy consumption and ow rate
through the heat pump heat exchanger are permanently constant.
The operating point (temperatures, ow rates) agreed in the
system datasheet must be ensured.
In any case, at least the minimum and maximum ow rate through
the condenser as specied in the machine data (see appendix)
must be maintained during heat pump operation. The ow rate
must lie within the specied minimum and maximum values.
The parameters specied in the system datasheets (in particular
temperatures, temperature spreads, ow rate) must be met during
heat pump operation. Modied system parameters can result in
di󰀨erent heat pump outputs and/or temperatures.
If CARRIER is not notied of a specic operating point/specic
temperature spread in good time, the heat pump will normally be
sized with temperature di󰀨erentials of 5 K between condenser
inlet and outlet. In this case these values will have to be complied
with during heat pump operation.
As standard, the heat exchanger connections are Flange unions.
Ensure that these connections are not reversed. For the position
of these connections (inlets and outlets), see the dimensions sheet
in the appendix. The connections must be tension-free and be
made with anti-vibration ttings.
When installing pipework, take care to avoid transmission of
structure-borne sound.
When sizing the heating circuit pump/bu󰀨er charging pump, the
internal pressure di󰀨erential of the heat pump condenser must
be taken into account (in accordance with the operating point
data).
Heating water must be treated according to VDI 2035, Ö-NORM
5195 or EN 14336. The limit values specied in Table 1 must
always be observed.
Ensure that no dirt or foreign bodies can enter the condenser. We
strongly recommend that you install a lter, dirt separator, or at
least a lter strainer, upstream of the condenser inlet.
Ensure that the lter is easily accessible and regularly cleaned. A
clogged strainer signicantly impairs heat transfer and can cause
a high pressure safety shutdown. Install valves and thermometers
in the ow and return lines to allow continuous monitoring of the
water ow rate and the heat pump operating state. At the lowest
point in the pipework, t a drain pipe to allow the system to be
drained. Size the heating pipework according to the heat pump
specication.
The ow velocity in the pipework should not exceed 1.0 m/s (noise/
pressure drop).
Regarding the temperature spread, please note the need for bu󰀨er
tank cooling: assuming that the heating water bu󰀨er tank has been
fully charged to the required temperature, the heat pump must
then be stopped (via remote ON/OFF) until the bu󰀨er tank has
cooled down again su󰀩ciently or the system can operate at the
design temperature spread again. If, for example, the set
temperature is 85 °C and the temperature spread between
condenser inlet and condenser outlet is 10 K, the heat pump should
run only when the temperature at the condenser inlet is 75 °C or
less (see also section 6.2).
Before commissioning the heat pump, ensure that the condenser
circuit contains no air or other gases and the consumer system
has reached operating pressure.
CAUTION! The water quality must be regularly checked.
Incrustations or acidic deposits could impair the condition
and function of the heat exchanger.
CAUTION! Impermissible media and substances they may
contain can destroy the components in the hydraulic circuit.
Abrasive solids (e.g. sand) increase wear.
Excessively hard water can result in deposits on the pipe inner
walls, which could impair the heat exchanger performance.
The heat exchanger must not be exposed to dynamic or local
loads. Dynamic excess pressure and water hammer can damage
the heat exchanger.
Exceeding the highest permissible ow rate can cause erosion
and damage the condenser.
After draining the condenser water circuit, always thoroughly dry
the condenser tubes to prevent corrosion.
Pump cavitation and gas in the hydraulic circuit must be prevented.
During prolonged idle times, completely charge the heat exchanger
or fully drain and dry it.
WARNING! Never open the heat exchanger under pressure.
Risk of scalding.
4.6 - Source energy connection (WQA)
Sizing and routing the source system is the system installer’s
responsibility and must be carried out in compliance with CARRIER
guidelines.
The system installer must size and install all components required
for the hydraulic circuit (e.g. safety valve, diaphragm expansion
vessel, air vent valve, etc.).
WARNING! The upper pressure limit and maximum
temperatures of the heat pump evaporator specied in the
machine data (see appendix) must not be exceeded at any
time. This applies regardless of whether or not the heat pump
is running and whether the heat transfer medium in the
evaporator is owing or at rest.

10
4 - INSTALLATION
To ensure this, install pressure relief devices in the pipework and
service/check them regularly. Ensure that there are no shut-o󰀨
valves in the pipework between the heat pump connection and
the next pressure relief devices.
In addition to the mass ow to be dumped by the operator in an
emergency, the pressure relief device must additionally be able
to dump a mass ow corresponding to the required minimum
refrigerant blow-down capacity Qmd (see safety valve calculation
in section 10).
The heat pump must be operated only within the permissible
limits of use (see appendix). The system installer/operator must
ensure that the limits of use are maintained.
The temperature of the heat transfer medium at the evaporator
outlet must not fall below 4°C.
When selecting and sizing lines, observe the applicable general
and national standards, conditions and guidelines. The latest
applicable engineering standards must be taken into account and
observed.
We recommend hydraulic separation of the heat pump and heat
source. This separation can be achieved with a separate heating
circuit connected to a low loss header or bu󰀨er tank. On the source
side (evaporator), ensure su󰀩cient bu󰀨er volume – at least 15
litres per kW of cooling capacity. A smaller bu󰀨er tank can only be
used in exceptional cases and at the user’s own risk if the energy
supply and ow rate through the heat pump heat exchanger are
permanently constant.
The operating point (temperatures, ow rates) agreed in the
system datasheet must be ensured.
In any case, at least the minimum and maximum ow rate through
the evaporator as specied in the machine data (see appendix)
must be maintained during heat pump operation. The ow rate
must lie within the specied minimum and maximum values.
The parameters specied in the system datasheets (in particular
temperatures, temperature spreads, ow rate) must be met during
heat pump operation. Modied system parameters can result in
di󰀨erent heat pump outputs and/or temperatures.
If CARRIER is not notied of a specic operating point/specic
temperature spread in good time, the heat pump will normally be
sized with temperature di󰀨erentials of 4–5 K between evaporator
inlet and outlet. In this case these values will have to be maintained
during heat pump operation.
As standard, the heat exchanger connections are Flange unions.
Ensure that these connections are not reversed. For the position
of these connections (inlets and outlets), see the dimensions sheet
in the appendix. The inlet and outlet are also labelled on the
evaporator. The connections must be tension-free and be made
with anti-vibration ttings.
When installing pipework, take care to avoid transmission of
structure-borne sound.
When sizing the source circulation pump, the internal pressure
di󰀨erential of the heat pump evaporator must be taken into
account (in accordance with the operating point data).
Use only suitable media in the evaporator circuit. The limit values
specied in Table 1 must always be observed.
Ensure that no dirt or foreign bodies can enter the evaporator. We
strongly recommend that you install a lter, dirt separator, or at
least a lter strainer, upstream of the evaporator inlet.
Ensure that the lter is easily accessible and regularly cleaned. A
clogged strainer signicantly impairs heat transfer and can cause
a safety shutdown. Install valves and thermometers in the ow
and return lines to allow continuous monitoring of the water/brine
ow rate and the heat pump operating state. At the lowest point
in the pipework, t a drain pipe to allow the system to be drained.
Size the pipework according to the heat pump specication.
The ow velocity in the pipework should not exceed 1 m/s (noise/
pressure drop).
Regarding the temperature spread, please note the need for
source bu󰀨er tank charging: assuming that the source bu󰀨er tank
has been fully cooled to the required temperature, the heat pump
must then be stopped (via remote ON/OFF) until the bu󰀨er tank
has charged up again su󰀩ciently or the system can operate at the
design temperature spread again. If, for example, the set
temperature is 10°C and the temperature spread between
evaporator inlet and evaporator outlet is 5 K, the heat pump should
run only when the temperature at the condenser inlet is 15°C or
more (see also section 6.2).
Before commissioning the heat pump, ensure that the evaporator
circuit contains no air or other gases and the system has reached
operating pressure.
CAUTION! The water or brine quality must be regularly
checked. Incrustations or acidic deposits could impair the
condition and function of the heat exchanger.
CAUTION! Impermissible media and substances they may
contain can destroy the components in the hydraulic circuit.
Excessively hard water/brine can result in deposits on the pipe
inner surfaces, which could impair the heat exchanger
performance.
The heat exchanger must not be exposed to dynamic or local
loads. Dynamic excess pressure and water hammer can damage
the heat exchanger.
Exceeding the highest permissible ow rate can cause erosion
and damage the evaporator.
After draining the evaporator water or brine circuit, always
thoroughly dry the evaporator tubes to prevent corrosion.
Pump cavitation and gas in the hydraulic circuit must be prevented.
During prolonged idle times, completely charge the heat exchanger
or fully drain and dry it.
WARNING! Never open the heat exchanger under pressure.
Risk of scalding.

11
4.6.1 - Water as heat transfer medium (61CW-Z heat
pumps)
If water is used as the heat transfer medium, use only clear water
with no turbidity. If using water, we further recommend the use of
a large area lter with a gauge of 500 µm (0.5 mm).
Before installing a system, carry out a water analysis.
The water for analysis should be sampled just before the end of
continuous pumping operation and analysed immediately.
Corrosive and coking substances can cause corrosion and silting
of evaporator, submersible pump and pipework (heat pump failure).
Check the source temperature/evaporator inlet temperature: it
must not be below 8 °C without special measures. The evaporator
outlet temperature must not be allowed to fall below 4°C.
Otherwise there is a risk of freezing, with a potential for total failure
through water ingress into the refrigerant circuit.
When using water with an above average corrosion potential or
dirty water, a warranty cannot be given without special protection
measures (please check with CARRIER and observe their
guidelines).
For a sealed water circuit, the water must be treated according to
VDI 2035, Ö-NORM 5195 or EN 14336. The limit values specied
in Table 1 must always be observed.
Only clear water with no turbidity is suitable, with permissible
values as specied below:
Table 1: Application limits of shell and tube heat
exchangers
pH-value (25°C) 6,8 - 9,0
Conductivity [µ– Siemens /cm] (at 25°C) < 800
Chloride [mg Cl-/l] < 150
Chloride (molecular) [mg Cl2/l] < 5
Sulphate [mg SO4- -/l] < 100
Sodium nitrate [mg NaNO3/l] < 100
Alkalinity [mg CaCO3/l] < 100
Total hardness [mg CaCO3/l] < 200
Iron [mg Fe/l] < 1,0
Copper [mg Cu/l] < 1,0
Sulphides [S -/l] No
Ammonium [mg NH4+/l] < 1,0
Silicon [mg SiO2/l] < 50
Maximum particle size (lter gauge) [mm] 0,5
Maximum dissolved solids, total salinity [mg/l]
Total Dissolved Solids (TDS) is the sum of mobile ions,
including minerals, salts or metals, dissolved in a specic
volume of water.
<1500
Maximum ethylene, propylene glycol 50 %
CAUTION! When using water as medium, the outlet
temperature at the evaporator must not be allowed to fall
below 4°C.
4.6.2 - Brine as heat transfer medium (61CW-Z heat
pumps)
The design of the source connection is such that the brine circuit
can be ushed if necessary.
Use only the antifreeze listed in Table 1. For the highest permissible
concentration of this antifreeze, see also Table 1. Note that the
antifreeze concentrations also a󰀨ect the heat pump performance.
The antifreeze must not be mixed with corrosive raw water (pH
value below 7.0), distilled water or rain water. Check the frost
protection, pH value and reserve alkalinity. Tests must be carried
out with a representative quantity (e.g. 3x 1/4 l). Check the mixing
ratio is suitable with a refractometer. Fill the system in such a way
as to ensure correct venting.
When operating with brine, lines and system components carrying
brine must be lled only with premixed heat transfer medium.
The antifreeze must have a su󰀩cient concentration to prevent
freezing. The evaporator outlet temperature must always be at
least 4 K above the brine freezing point.
4.7 - Electrical connection
DANGER! When working on electrical equipment, there is a
risk to life from electric shock.
Before any work on electrical equipment, isolate it from the
power supply and secure against unintentional reconnection.
DANGER! The control cabinet must remain closed while the
heat pump is running!
The key to the control cabinet must be kept separately.
Observe the regulations of the responsible power supply utility
and the applicable EN standards. The control cabinet is rated IP
54 by the manufacturer. Ensure that the IP 54 rating is still
maintained after installation of the power cable.
The fuse ratings listed below are guideline values only. The
electrician who carries out the installation is responsible for sizing
the power cable and tting the correct protective devices. All
relevant factors must be considered, such as length, ambient
temperature, etc.
Protection of the power cable with low voltage HRC fuse links
must be sized selectively, i.e. one stage higher than the protection
inside the heat pump control cabinet. For selectivity, use a
guideline value of 1:1.6. The power cable must be protected
against overload and short circuit. The sizes of the recommended
low voltage HRC fuse links are listed in Table 2.
CARRIER does not accept liability for faults or losses resulting
from incorrectly designed protective equipment!
The outputs to a source energy pump or consumer energy pump
are equipped with motor overload relays and protected against
overload and short circuit.
The individual cores of the power cable must be tted with suitable
cable lugs and connected to the main emergency stop switch with
the specied torque (see Table 2 and Fig. 2).
4 - INSTALLATION

12
Table 2
Heat pump type Max. operating
current, compressor
Power cable
protection
(selectivity 1:1.6)
Torque of
terminal screw
Copper power cable,
minimum cross-
section up to 50 m
Single core copper
power cable,
minimum cross-
section up to 50 m
61CW-Z 392 295A LV HRC 400 A M10 - 31 Nm 4 x 240 mm²
2 x 4 x 95 mm² 4 x 185 mm² 2 x 4 x 70 mm²
61CW-Z 472 361A LV HRC 500 A M10 - 31 Nm 4 x 300 mm²
2 x 4 x 120 mm² 4 x 24 mm² 2 x 4 x 95 mm²
61CW-Z 572 428A LV HRC 500 A M10 - 31 Nm 4 x 300 mm²
2 x 4 x 120 mm² 4 x 240 mm² 2 x 4 x 95 mm²
61CW-Z 742 551A LV HRC 630 A M10 - 31 Nm 2 x 4 x150 mm² 2 x 4 x120 mm²
Fig. 2
B
C
D
8 mm
31 Nm
(274 lb-in)
The cable cross-sections listed in Table 2 apply to a cable length
of up to 50 m at an ambient temperature not exceeding 30 °C. In
each case, the electrician responsible must ensure appropriate
sizing.
The power cables must be used to create a clockwise rotating
eld. The clockwise rotating eld must be ensured before
commissioning.
Caution: Operation with the wrong rotational direction will
result in compressor damage.
DANGER! Connection work which requires electrical
distributors to be opened must be carried out by authorised
electricians, since there is a risk to life when working on live
components.
Observe the accident prevention regulations.
CAUTION! Only CARRIER customer service may start the
heat pump for the rst time.
4.8 - Fitting sensor leads
Route sensor leads in separate conduits or preferably use
screened leads to avoid induction and resulting controller
malfunction.
If installing an outdoor temperature sensor for the controller, t it
at a height of about 2.5 m on an outside wall of the building (north-
west side). Make sure that the temperature sensor is not exposed
to direct sunlight or wind, as this will impair the control behaviour.
Caution: Never apply voltage to sensor terminals. (Destruction
of the controller).
4 - INSTALLATION

13
5 - COMMISSIONING
Commissioning should be requested from CARRIER customer
service. A binding commissioning date must be logged at
least 6 weeks in advance. Please contact our customer
service.
To be able to carry out commissioning, the following work must
have been completed:
■The hydraulic installation of the WQA and WNA must have been
completed. The system must be lled, vented, hydraulically
adjusted and all functions checked.
■Source energy and consumption must be available in adequate
form to allow continuous operation of the heat pump.
■The ow rates according to the system datasheet must be
permanently ensured.
■ The heat pump must have been electrically connected by an
authorised electrician.
■ The system must be connected to the low voltage mains with
3 x 400 V / 50 Hz and the on-site electrical installation must be
completed. Ensure a clockwise rotating eld; no provisional
installations!
■In order to activate the oil heating, the following must be
implemented 24 h before CARRIER customer service
arrives: connect the 230 V control voltage to the heat pump,
move the switch for fault protection (15F1) and the circuit
breaker (15F3) into the active position, and subsequently,
with the control cabinet closed, turn the mains isolator to
the “ON” position. At this point, there must not yet be 400
V present at the control box.
-The oil heater in the oil separator then begins to heat the oil,
so that the system is ready to operate at the start of
commissioning.
■ For water/water heat pumps
-The pipes must be lled and checked for leaks.
■ For brine/water heat pumps
-The brine system must be charged, vented and ready for
operation.
Persons required on site:
Electrician, installer and the future system operator or user for
training.
Work carried out by CARRIER:
■ Setting the safety devices
■ Checking the switching sequence
■ Drawing up a commissioning report
■ Making standard control unit settings
■Introduction, briefing of the operator (if present during
commissioning)
Special work such as venting, electrical connection, etc., not
included in CARRIER’s scope of supply will be invoiced separately.
If additional work is required or there are downtimes during
commissioning because the system is not fully prepared, the
additional time will be chargeable.
CAUTION! Let only trained specialist personnel carry out
adjustments and troubleshooting!
Standard controller settings are made during commissioning by
CARRIER specialists.
CAUTION!
Only CARRIER customer service may start the heat pump
for the rst time. The system operator/customer may only
restart the system when commissioning and brieng have
been fully completed by CARRIER customer service (see
section 6.1).

14
6 - OPERATION
Operating and fault display:
The heat pump is equipped with an integral fault display.
The operating conditions and any faults are indicated in detail on
the heat pump touchscreen.
When the cause of the fault has been eliminated, the system can
be reactivated with a RESET.
If the monitors for rotating eld, oil level, oil temperature or winding
temperature respond, this must be acknowledged with the key
switch on the front of the control cabinet after the fault has been
eliminated.
For a detailed explanation of how to operate the heat pump using
the touchscreen, see the controller description in the appendix
(section 10).
6.1 - Restarting
Before switching on the system, the operator/customer
must check and (if necessary) repair or correct the
following on both sides of the heat pump:
System pressure, function of the expansion vessel, venting, ow
rate
Check that all shut-o󰀨 valves are open
Check the voltage supply
Check that the controller is set to the required operating mode
Additionally for brine/water heat pumps:
System pressure, frost protection additive
Additionally for water/water heat pumps:
Filter, water quality
The heat pump is switched on via the mains isolator (ON/OFF),
which is located on the front of the heat pump control cabinet.
After the preheating time (see section 5), the heat pump can be
started with the ON key on the touchscreen.
When correctly installed, the heat pump works fully automatically
and without user interaction.
WARNING! During operation and subsequent stops, the
surfaces of the heat pump are hot. Risk of burns on contact
with heat pump components!
6.2 - Control
Depending on the control mode, the heat pump can automatically
meet the expected or currently required target. It can also provide
control of the pumps on the source and condenser sides, so that
these also operate automatically.
On systems in which the bu󰀨er tank temperatures are monitored
by the heat pump, suitable positions must be chosen for the bu󰀨er
sensors.
It is often necessary or preferable to control the heat pump through
an external building management system (BMS).
In all cases, the heat pump must operate for at least 10 minutes
and stand idle for at least 6 minutes!
6.2.1 - Temperature control (default set values):
Depending on the selected control mode, a target value for the
evaporator or condenser inlet or outlet temperature can be
specied to the controller. The following are possible:
■Fixed target (set by our customer service department at
administrator level during commissioning)
■ External target with 0-10 V signal via analogue input
-A target value band is assigned to the specied input signal
shape (e.g.: 0 V = 75 °C; 10 V = 92 °C). According to the
target at the input (± hysteresis), the compressor and, if
applicable, source and condenser pumps are started by the
internal control unit and switched o󰀨 again when the target
has been reached.
-The target value band can extend over an annual requirement
prole to also meet cooling requirements. In this case, a
second digital input signal to dene the operating mode (e.g.
0 = heating operation; 1 = cooling operation) is required.
-Depending on the parameter settings, 0-10 V in cooling mode
then corresponds to a target (on the evaporator side) of e.g.:
10 – 18°C, and in heating mode (on the condenser side) of
e.g.: 80 – 92°C.
■ External target with 4-20 mA signal via analogue input (see
description above)
■ External target via Modbus interface
6.2.2 - Link-up to a BMS:
In addition to the target input, the control unit o󰀨ers the following
inputs and outputs:
Inputs:
■ External alarm (the heat pump stops)
■ Changeover between heating and cooling
■ Remote ON/OFF
-With this input, the heat pump can be enabled or disabled
by means of a digital input signal. The heat pump starts only
if the enable signal has been issued and the operating
conditions are met.
-To prevent the heat pump cycling, it is advisable to disable
the heat pump enable signal as soon as operating conditions
occur
• That deviate from the operating point(s) agreed in the
system datasheet and/or
• That lie outside the permissible limits of use.
The enable signal should be re-enabled only when
temperatures allow operation of the heat pump at least with
the minimum runtime.
-As long as the external enable signal is applied and the heat
pump controls the circulation pumps (see below), the
circulation pumps are active to capture the correct operating
conditions (ow temperature) at all times.

15
6 - OPERATION
Outputs:
■ Compressor status message (compressor running)
■ Fault message (heat pump has a fault)
■ Message of readiness for operation (the heat pump is ready
for operation, i.e. switched on and fault-free, and may be started
at any time via remote ON/OFF)
■ Compressor running at 100 % output
■ Enables external control of a 3-way valve on the condenser
(when the 3-way valve is not switched by the heat pump)
■ Enables external control of a 3-way valve on the evaporator
(when the 3-way valve is not switched by the heat pump)
■ 0-10 V di󰀨erential temperature, condenser (pump control unit)
■ 0-10 V di󰀨erential temperature, evaporator (pump control unit)
6.2.3 - Control of peripherals:
In this context, peripherals are circulation pumps on the source
(evaporator) and condenser side.
Control by CARRIER heat pump:
The external source and condenser pumps can be controlled by
the heat pump controller. The required prerun and overrun times
are set by CARRIER customer service for each specic application.
The type of control is specied in the system datasheet.
Control via external building management system:
The external BMS fully regulates the targets, controls the system
peripherals (pumps, dampers, valves, etc.) and only requests
active heating or cooling from the heat pump.
In this context, the following functions must be ensured:
■ The source pump must be started approximately 1.0 minute
prior to the heat pump being enabled and must run on for around
1.0 minute after the compressor has stopped (feedback signal).
■ The condenser pump (consumption side) must start up at least
0.5 minutes before the compressor and run on for at least 0.5
minutes.
■ The compressor must not be switched more than 4 times per
hour.
■ The standard minimum operating time must not fall below 10
minutes.
To the extent required, the external BMS receives a feedback
signal about the actual operating state of the compressor by means
of a oating contact (standby, compressor running or safety shut
down). The source and condenser pumps must always run when
the compressor is working to prevent faults and damage to the
heat pump. We recommend linking the prerun and overrun timers
to the enable and feedback signals.
If the source and condenser pumps assume other functions outside
heat pump operation, it makes sense to have the external BMS
control these circulation pumps.
Control of 3-way valves by CARRIER heat pump:
The heat pump control unit can regulate the voltage supply to and
switching of the external 3-way mixing valves (actuators), both on
the source and/or condenser side. In the standard version, the
heat pump issues a 0-10 V target signal to switch the 3-way valves
on the evaporator and/or condenser side.
A 4-20 mA signal can also be provided as an option. The 3-way
valves or their actuators must be installed so that they are 100%
open to a hydraulic system on the source or consumption at a 10
V target signal. When the target signal is 0 V, the valves should
be fully open towards the bypass (short circuit circulation).
A voltage supply is provided to drive the 3-way valves. This can
be either 24 V DC (standard) or 24 V AC.
The voltage supply and type of control are dened in the system
datasheet and may vary from the standard version.
The 3-way valves used must reach an actuating time (duration
from fully open to fully closed state and vice versa) of maximum
30 seconds, 16 seconds is better.
6.2.4 - Bu󰀨er tank
The text below describes the heat pump in heating mode as an
example (target at condenser outlet), but it applies vice versa to
cooling mode (target at evaporator outlet).
Note that, depending on the hydraulic system and the temperature
spread, the heat pump target (condenser outlet) generally has to
be higher than the required temperature in the bu󰀨er tank. If for
example a temperature of 60°C is to be reached in the heating
bu󰀨er tank, the heat pump should generally be set a target value
>60°C (temperature raising).
Once the bu󰀨er tank has been heated to approximately the
required target temperature and the heat pump is o󰀨/shutting
down, the heat pump should remain o󰀨 (via the remote ON/OFF)
until the buffer tank has cooled down again or the agreed
temperature spread across the condenser could be controlled
again at least over the minimum runtime.
If, for example, the target temperature for the condenser outlet is
60°C and the agreed temperature spread between condenser inlet
and condenser outlet is 10K, the heat pump should only run when
the temperature at the condenser inlet is 50°C or less.
If, for example, the target temperature for the evaporator outlet is
8°C and the agreed temperature spread between evaporator inlet
and evaporator outlet is 10K, the heat pump should only run when
the temperature at the evaporator inlet is 18°C or more.

16
6 - OPERATION
6.3 - Safety functions
Compressor protection device
CARRIER industrial heat pumps are equipped with a protection
device for the screw compressor as standard. The protection
device is installed in the compressor terminal box.
Safety monitoring by the compressor protection device:
■Temperature monitoring
The compressor protection device locks out as soon as the
highest permissible motor or oil temperature is exceeded.
■ Rotational direction monitoring
The compressor protection device monitors the rotational
direction in the rst 5 seconds after the compressor has started.
If the compressor starts in the wrong direction, the protection
device locks out immediately. In addition, CARRIER uses a
second, upstream rotational direction monitor, which prevents
the compressor starting in the wrong direction in advance.
■ Phase failure monitoring
In the event of a phase failure within the rst 5 seconds after
the compressor has started, the protection device immediately
opens the relay contact in the safety chain and closes it again
after 6 minutes. It fully locks out after 3 phase failures inside
18 minutes or after 10 phase failures within 24 hours.
Further safety equipment:
■ Motor overload relay for the compressor
■ Motor overload relay for the required source pump
■ Motor overload relay for the required condenser pump
■ High and low pressure controller
■ High and low pressure sensors
■ Hot gas temperature monitor
■ Frost protection monitor
■ Di󰀨erential pressure switch at the evaporator
■ Flow switch for the evaporator is optionally available and is
recommended by CARRIER for low evaporator inlet
temperatures.
■ Di󰀨erential pressure switch for lter in the oil circuit
Safety valve:
A safety valve discharge pipe must discharge the refrigerant to
the ambient air or to removal devices in a suitable manner or direct
it into absorbent material available in an adequate amount. The
refrigerant must not be directed into adjacent rooms, stairwells or
similar. The refrigerant must not be brought into contact with an
air supply for combustion engines, boilers or air compressors.
If for improved service quality a sealed ball shut-o󰀨 valve is tted
upstream of the safety valve on the condenser, note the following:
as soon as the valve service has been completed, the ball shut-o󰀨
valve must be checked while in the open position and sealed by
a qualied inspection body in accordance with the Pressure
Equipment Directive 2014/68/EU.

17
7 - MAINTENANCE
7.1 - Service work
Ensure the following:
■The water/brine lter system is regularly inspected and cleaned.
■The water/brine circuit is always vented and the medium quality
is regularly checked and maintained.
■ The system is shut down when cleaning the heat exchanger.
■If dirty, the heat exchanger is not cleaned with excessively
corrosive chemical cleaning agents, unsuitable tools or
excessively powerful pressure jets.
■Safety valve
The refrigerant safety valve opens at a dened maximum
pressure that has been calculated for the heat pump. The valve
is generally maintenance-free. After a response, however, a
steady leakage of refrigerant may occur. This results in a loss
of performance and a higher hot gas temperature. In this case,
please contact CARRIER customer service.
■Integral non-return valve
To protect the compressor against running in reverse (expansion
operation) at standstill, a non-return valve is installed under the
pressure shut-o󰀨 valve. If the compressor runs in reverse for
more than about 3 seconds after being switched o󰀨, this valve
may be faulty and must be replaced. The inspection interval
for the non-return valve is 5000 hours or at least once a year.
■Roller bearings
If the compressor is operated with less than 4 starts/stops per
hour and always within the application limits, the expected
service life of the roller bearings is 100,000 hours. However, it
is advisable to inspect and (if necessary) replace the
compressor bearings after 40,000 hours. For this purpose, a
separate maintenance request must be sent to CARRIER
customer service (not covered by the maintenance contract).
■Oil
When replacing the bearings, the oil and oil lter should also
be changed.
■Control cabinet
The fans are maintenance-free. With active lter mats, the
control cabinet interior does not have to be cleaned. Clean or
replace the lter mats as required (this depends on the ambient
conditions). Clean undamaged lter mats by beating them out
or by carefully blowing them clean with compressed air.
Damaged lter mats should be replaced.
■Shut-o󰀨 valves
A Rotalock valve is tted to the refrigerant outlet at the bottom
of the condenser. It may only be closed while the lter dryer is
being serviced. If a ball shut-o󰀨 valve is tted in the line
downstream of the lter dryer, this may also only be closed
during servicing of the lter dryer. In this case, the main
expansion valve must be opened. To do so, rst log in the
ADMIN user on the touchscreen, then manually set the
expansion valve opening to 100%. Ensure that the expansion
valve remains open during servicing and until the ball shut-o󰀨
valve is reopened. Both valves (Rotalock valve on the
condenser and ball shut-o󰀨 valve downstream from the lter
dryer) must then be secured against unintentional closing.
For maintenance of the oil lter, the ball shut-o󰀨 valves upstream
and downstream of the lter must be closed, reopened again
after maintenance, and secured against unintentional closing.
If there is a ball shut-o󰀨 valve in a line leading to the compressor,
this serves to regulate the compressor temperature and must
not be touched under any circumstances.
The Rotalock valves on the compressor are only used for
technical approval and must not be touched.
Once per year, carry out a function check on the safety equipment
(pressure switches, thermostats, hot gas sensors).
CARRIER recommends at least an annual inspection of the heat
pump by CARRIER customer service.
A maintenance contract is available from CARRIER on request.
If required, please contact our customer service. As part of a
maintenance contract, CARRIER customer service carries out the
work specied in section 0.
The service work specied in the F-gas regulations must be carried
out.
7.2 - Inspection by the operator
The heat pump should be visually inspected for leakages once a
week. For this, pay particular attention to the connections on the
compressor and to the oil circuit.
Check the oil level in the oil separator once a week. This must be
checked while the system is in operation. Please contact CARRIER
customer service if the oil level falls below the lower sight glass.
In the event of leakage, please contact CARRIER immediately.

18
7 - MAINTENANCE
7.3 - Customer service
CARRIER customer service carries out the following work as part of a maintenance service (rough overview):
■ Inspection of the refrigerant and oil circuits (oil check)
■ Inspection and retightening of electrical terminals
■ Testing of safety equipment (pressure switches, thermostats, hot gas sensors)
■ Checking of switching contacts
■ Entries in the service book
■ Checking of control parameters
Should your appliance develop faults despite the use of quality components and care in its production, please contact customer service
on the phone number below, giving the serial number and model of your heat pump.
The heat pump model and serial number are given on the type plate. The type plate is located externally on the side of the control
cabinet.

19
8 - TROUBLESHOOTING
8.1 - Alarm messages on the touchscreen
The operating state and any faults can be identied on the touchscreen using the controller descriptions (see appendix). The table
below lists general fault messages, possible causes and recommendations for rectifying the fault.
Table 3
Text displayed on touchscreen Possible cause Troubleshooting
Phase monitor alarm
Phase failure in compressor
Oil temperature too high
Compressor motor too hot
Check power supply; check compressor fuses;
check soft starter; check oil level
Alarm: evaporator ow Water ow rate through evaporator too low Check evaporator pump, clean water lter
Fault: high pressure (pressure switch) Water ow rate through condenser too low Check condenser pump
Low pressure fault (pressure switch) Refrigerant loss source water temperature too
low
Contact refrigeration engineer;
Contact CARRIER
Evaporator pump or condenser pump
overload Motor overload relay responded Check source energy pump or condenser pump; check motor overload relay
Compressor overload Motor overload relay or soft starter responded Check power supply; check compressor
terminals and check motor overload relay
Frost alarm Water ow rate too low; source water
temperature too low
Check water ow rate and increase if necessary;
determine source water temperature
Alarm: low di󰀨erential pressure High pressure too low; source water
temperature too low
Contact refrigeration engineer;
Contact CARRIER
Alarm: high pressure (sensor) Water ow rate through condenser too low Check ow rate
Alarm: low pressure (sensor) Refrigerant loss Contact refrigeration engineer;
Contact CARRIER
Sensor faulty or not connected
Sensor failure or broken lead; the a󰀨ected
sensor is identied in the alarm message text or
in the controller description (inputs/outputs) Check sensors, sensor leads and terminals
Compressor outside
Limits of use
Inlet or outlet temperatures at evaporator or
condenser outside permissible range Contact refrigeration engineer; Contact CARRIER
In the event of a low pressure fault or an overload message, notify CARRIER customer service immediately.
8.2 - General troubleshooting
Table 4
Fault Possible cause Troubleshooting
Heat pump not working
Mains isolator in OFF position
Faulty fuse
Faulty LV HRC
Power cable break
Power failure
Switch on
Correct fault; replace fuse
Correct fault; replace LV HRC
Correct fault; switch on
Heat pump restarts after expiry of the preheating
phase (point 3)
High pressure fault
Energy transfer not ensured
Heating circuits excessively restricted
one or more circulation pumps are not pumping
Speed (output stage) of heating circulation
pump too low or heat pump is too large
Air in heating circuit
Non-return valve stays shut
with optional external DHW heating:
-Heat exchanger too small
-Heat exchanger scaled up or silted up
High pressure switch incorrectly set
Loose terminal connections
Open shut-o󰀨 valves
Re-establish function
Increase pump speed (stepper switch), ow/
return spread ∆t = 5 K
Vent heating circuit
loosen, replace
Enlarge
Notify customer service
Clean, descale
Correct the setting
Establish rm terminal connections

20
8 - TROUBLESHOOTING
Fault Possible cause Troubleshooting
Low pressure fault
Air in source energy circuit
Not enough frost protection additive
Not enough water/brine
Line leaks
Filter dirty (water)
Submersible pump clogged
Submersible pump running in wrong direction
Geothermal store exhausted
(brine inlet temperature ≤ -4 °C)
Submersible pump faulty
Low pressure switch set too low
Refrigerant loss
Refrigerant circuit faulty
Vent
Correct
Increase water/brine volume
Replace
Clean, backwash
Repair, clean
Correct rotational direction
Regenerate/enlarge geothermal store (interim
solution: signicantly reduce heating mode;
activate auxiliary heater, e.g. electric immersion
heater)
Replace
Correct the setting
Notify customer service
Top up refrigerant
Notify customer service
Brazing, renew
Frost protection shutdown through primary
temperature sensor Source energy insu󰀩cient or too low -
Heating system is not hot; heat pump up to
bu󰀨er tank/low loss header is hot Energy transfer is interrupted or too low
Replace circulation pump,
vent heating circuit,
open gate valve, open control valves,
increase circulation pump output stages
Heat pump running; heating output is too
low
Excessive heat demand
Source system overstretched
Building design specication not met (e.g.
thermal insulation)
Reduce heat load
Reduce heat load
Ensure building meets its design specication
Heat pump runs continually and yields
only low temperature; traces of oil in the
appliance
Refrigerant leak
Threaded connections are loose; refrigerant line
leaks
Switch o󰀨 heat pump,
notify customer service
To clarify the cause of the fault, please contact your heating installer/electrician. If the faults are denitely not the result of any of the
causes listed here, please contact our customer service.
CAUTION! Adjustments and troubleshooting may only be carried out by trained specialists!
Standard controller settings are made during commissioning by CARRIER specialists.
Subject to technical modications!
This manual describes appliances that are not always standard items. There may therefore be di󰀨erences to your specic heat pump.
System installer:
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Company name
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Address
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Tel.
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Installer
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