Viessmann VITOCAL 300-G PRO Type BW 2150 Operating instructions

Installation and service instructions
for contractors
Viesmann
Vitocal 300-G Pro
Type BW 301.C090 to 302.C230, 82.8 to 296.0 kW
Heat pump, single and two-stage
For applicability, see the last page
VITOCAL 300-G PRO
5787 232 GB 09/2016 Please keep safe.

2
Please follow these safety instructions closely to
prevent accidents and material losses.
Safety instructions explained
Danger
This symbol warns against the risk of injury.
!Please note
This symbol warns against the risk of material
losses and environmental pollution.
Note
Details identified by the word "Note" contain additional
information.
Target group
These instructions are exclusively intended for author-
ised contractors.
■Work on the refrigerant circuit may only be carried
out by authorised refrigeration engineers.
■Work on electrical equipment must only be carried
out by a qualified electrician.
■The system must be commissioned by the system
installer or a qualified person authorised by the
installer.
Regulations to be observed
■National installation regulations
■Statutory regulations for the prevention of accidents
■Statutory regulations for the protection of the envi-
ronment
■Codes of Practice of the relevant trade associations
■All relevant safety regulations as defined by DIN, EN,
DVGW, VDE and locally applicable standards
aÖNORM, EN and ÖVE
cSEV, SUVA, SVTI, SWKI and SVGW
Working on the system
■Isolate the system from the power supply (e.g. by
removing the separate fuse or by means of a mains
isolator) and check that it is no longer 'live'.
Note
In addition to the control circuit there may be several
load circuits.
Danger
Contact with 'live' components can result in
severe injuries. Some components on PCBs
remain 'live' even after the power supply has
been switched off.
Wait at least 4 minutes before removing equip-
ment covers, to allow the voltage to dissipate.
■Safeguard the system against reconnection.
!Please note
Electronic assemblies can be damaged by elec-
trostatic discharge.
Prior to commencing work, touch earthed
objects such as heating or water pipes to dis-
charge static loads.
Repair work
!Please note
Repairing components that fulfil a safety func-
tion can compromise the safe operation of your
system.
Replace faulty components with genuine
Viessmann spare parts.
Auxiliary components, spare and wearing parts
!Please note
Spare and wearing parts that have not been tes-
ted together with the system can compromise its
function. Installing non-authorised components
and making non-approved modifications or con-
versions can compromise safety and may inva-
lidate our warranty.
For replacement, use only spare parts supplied
or approved by Viessmann.
Safety instructions
Safety instructions
5787 232 GB

3
1. Safety and liability Heat pump application limits .................................................................. 5
Occupational safety ............................................................................... 5
■Electrical connections ......................................................................... 5
■Work on the heat pump ...................................................................... 6
■Work on the refrigerant circuit ............................................................. 6
■Work on the casing ............................................................................. 7
2. Information Disposal of packaging ............................................................................ 8
Symbols ................................................................................................. 8
Intended use .......................................................................................... 8
Product information ................................................................................ 9
■Vitocal 300-G Pro ............................................................................... 9
3. Preparing for installation General information on electrical connection ......................................... 10
Transport and siting requirements ......................................................... 10
■Unloading and handling ...................................................................... 10
■Installation room requirements ........................................................... 12
■Minimum clearances ........................................................................... 13
■Anti-vibration base .............................................................................. 14
Requirements for on-site connections ................................................... 15
■Dimensions Vitocal 300-G .................................................................. 15
Hydraulic connection requirements ....................................................... 16
■Primary circuit: brine/water, 1-stage (type BW 301C.090 and
BW 301.C120) .................................................................................... 17
■Primary circuit: brine/water, 2-stage (type BW 302.C090,
BW 302.C110, BW 302.C140, BW 302.C180 and BW 302.C230) ..... 18
■Primary circuit: brine/water, heat pump cascade (type BW 301.C090
to BW 302.C230) ................................................................................ 19
■Heat pump cascade: 1-stage/2-stage (type BW 301.C090 to
BW 302.C230) .................................................................................... 20
■DHW heating (type BW 301.C090 to BW 302.C230) ......................... 21
4. Installation sequence Siting the heat pump .............................................................................. 23
■Levelling the heat pump ..................................................................... 23
■Removing the transport brackets ........................................................ 24
■Fitting the back panel, side panels and kicking plates ........................ 25
Making the hydraulic connections .......................................................... 26
■Overview of hydraulic connections ..................................................... 26
■Connecting the Vitocal 300-G ............................................................. 27
■Fitting the Victaulic couplings ............................................................. 28
■Connecting the primary circuit ............................................................ 29
■Connecting the secondary circuit ....................................................... 29
Electrical connections ............................................................................ 30
■Routing cables to the heat pump wiring chamber .............................. 30
■Overview of electrical connections ..................................................... 31
■Terminal strip for system components ................................................ 32
■Main PCB with expansion PCB .......................................................... 33
■Message and safety connections (safety chain) with distribution ter-
minal ................................................................................................... 39
■Controller and sensor PCB ................................................................. 42
■Electric booster heater (on-site) ......................................................... 44
Power supply ......................................................................................... 45
■Control circuit power supply (230 V~) and power circuit (400 V~) ..... 45
■Electrical connection requirements ..................................................... 46
■Power supply with power-OFF ........................................................... 47
■Electronic soft starter, type SMC ........................................................ 47
Fitting the shaft and dial for the ON/OFF switch and installing the pro-
gramming unit ........................................................................................ 49
Closing the heat pump ........................................................................... 49
Index
Index
5787 232 GB

4
5. Commissioning, inspec-
tion, maintenance
Steps - commissioning, inspection and maintenance ............................ 51
6. Troubleshooting Diagnosis ............................................................................................... 63
■Increased noise emissions ................................................................. 63
7. Repairs Removing the front panel and top panel ................................................ 64
Overview of electrical components ........................................................ 64
Overview of internal components .......................................................... 64
Draining the heat pump on the primary/secondary side ........................ 65
Checking sensors .................................................................................. 65
■Temperature sensors, type NTC 10 kΩ .............................................. 65
■Temperature sensors, type Pt500A .................................................... 66
Checking MCBs/fuses ........................................................................... 66
8. Parts lists Ordering parts ........................................................................................ 67
Parts, section 1 ...................................................................................... 68
Parts, section 2 ...................................................................................... 70
9. Commissioning/service
reports
Hydraulic parameter report .................................................................... 72
Control parameter report ....................................................................... 72
10. Specification Specification, Vitocal 300-G ................................................................... 80
11. Appendix Heat pump commissioning request ....................................................... 84
12. Final decommissioning Dismantling / Disposal ........................................................................... 85
13. Certificates Declaration of conformity ....................................................................... 86
14. Certificates Declaration of Conformity ...................................................................... 87
15. Keyword index ................................................................................................................ 88
Index
Index (cont.)
5787 232 GB

5
Intended use ■Generation of cooling and/or heating
■For use in industry, commerce, domestic households
System limit See P&I diagram, connection and wiring diagram
Service life
Heat pump 15 to 25 years
Wearing parts (filter dryer, refrigerant oil, com-
pressor)
Note
Refrigerant oil is available from your local re-
tailer.
4 to 5 years, subject to hours run and operating point
Occupational safety
Responsibilities during the lifecycle phases
Lifecycle System
user
External
person-
nel
Manufac-
turer
Refriger-
ation en-
gineer
Logistics Electri-
cian/
heating
contrac-
tor
Service
engineer
Disposal
contrac-
tor
Manufacture X X
Delivery, mov-
ing, handling,
siting
X X X X X
Installation X X X
Commission-
ing
X X X X
Operation X X
Maintenance,
repair, shut-
down
X X X X X
Dismantling,
removal, col-
lection
X X X X X
Disposal X X X
Electrical connections
Danger
Electromagnetic radiation near the wiring cham-
ber of the heat pump control unit can interfere
with electrical devices such as heart pacemak-
ers and defibrillators.
■Wearers of heart pacemakers:
Avoid the immediate vicinity of the heat pump
control unit wiring chamber; consult a doctor
beforehand if necessary.
■Store and use defibrillators outside the area at
risk.
Danger
Incorrectly executed electrical installations can
result in injuries from electrical current and dam-
age to the appliance.
Connect the power supply and implement all
safety measures (e.g. RCD circuit) in accord-
ance with the following regulations:
■IEC 60364-4-41
■VDE regulations
■Technical connection requirements specified
by the local power supply utility
Safety and liability
Heat pump application limits
5787 232 GB
Information

6
Danger
Contact with live components can lead to seri-
ous injury from electric current. Some compo-
nents on PCBs remain 'live' even after the
power supply has been switched off.
■Isolate the system from its power supply (e.g.
at a separate MCB/fuse or mains isolator),
check that there are no 'live' currents and
safeguard against reconnection.
Note
In addition to the control circuit there may be
several power circuits.
■Prior to removing the heat pump covers, wait
at least 4 min until the voltage has dropped
off.
■Never touch terminal areas of the heat pump
control unit or power connections (see
page 31).
Danger
The absence of component earthing can result
in serious injury from electrical current and in
component damage in the event of an electrical
fault.
■Always re-establish all earth connections of
the heat pump.
■The heat pump and pipework must be groun-
ded to the equipotential bonding of the build-
ing.
Note
Observe all information in the "Safety instructions".
For further information regarding electrical connec-
tions, see from page 30.
Work on the heat pump
Note
Before commissioning and after repair or maintenance
work, check that the heat pump is in the intended con-
dition.
Danger
Falling of heavy or unwieldy heat pump compo-
nents can result in life threatening crushing or
breaks.
■Always use suitable ropes/slings and lifting
gear when installing/dismantling compressors,
heat exchangers or similar.
■Wear appropriate protective clothing (e.g.
safety boots) in compliance with applicable
regulations on accident prevention and in line
with trade association recommendations.
Work on the refrigerant circuit
Danger
Direct contact with refrigerant can be harmful to
skin.
■Only work on the refrigerant circuit whilst
wearing safety goggles and safety gloves.
Note
Work on the refrigerant circuit must only be
carried out by a qualified refrigeration engi-
neer.
■Wear suitable protective clothing.
Danger
Refrigerant circuits of heat pumps develop
extremely low (–25 °C) and very high (+130 °C)
temperatures. Work on heat pumps can result in
life threatening frostbite and burns.
■Switch off the heat pump at least 30 min
before working on it.
■If at all possible, avoid touching the injection
valve and compressor; wear safety gloves, if
contact is necessary.
■Wear suitable protective clothing.
Danger
Refrigerant R410A is a non-poisonous gas that
displaces air. Unregulated escape of refrigerant
R410A in enclosed spaces can result in difficul-
ties in breathing and suffocation.
■Never breathe in refrigerant vapours.
■Ensure adequate ventilation in enclosed
spaces.
■Prevent open flames.
■Always observe regulations and guidelines on
handling this type of refrigerant.
Safety and liability
Occupational safety (cont.)
5787 232 GB
Information

7
Work on the casing
Danger
Breaking through the knockouts on the back
panel leaves behind sharp edges from the metal
retaining tabs that can lead to life threatening
injuries.
■Finish and seal the edges appropriately before
installation.
Note
Damage to the surfaces of the casing can lead to cor-
rosion.
Safety and liability
Occupational safety (cont.)
5787 232 GB
Information

8
Please dispose of packaging waste in line with statu-
tory regulations.
DE: Use the disposal system organised by
Viessmann.
AT: Use the ARA statutory disposal system (Altstoff
Recycling Austria AG, licence number 5766).
CH: Packaging waste is disposed of by the HVAC
contractor.
Symbols
Symbol Meaning
Reference to other document containing
further information
1.
Step in a diagram:
The numbers correspond to the order in
which the steps are carried out.
Warning of material losses and environ-
mental pollution
Live electrical area
Pay particular attention.
■Component must audibly click into place.
or
■Acoustic signal
■Fit new component.
or
■In conjunction with a tool: Clean the sur-
face.
Dispose of component correctly.
Dispose of component at a suitable collec-
tion point. Do not dispose of component in
domestic waste.
The steps in connection with commissioning, inspec-
tion and maintenance are found in the "Commission-
ing, inspection and maintenance" section and identified
as follows:
Symbol Meaning
Steps required during commissioning
Not required during commissioning
Steps required during inspection
Not required during inspection
Steps required during maintenance
Not required during maintenance
Intended use
The Vitocal 300-G Pro heat pumps, type BW 301.C090
to 302.C230 can be used for the following purposes:
■Central heating and cooling via a heating system
■DHW heating
■Swimming pool heating
Information
Disposal of packaging
5787 232 GB
Information

9
The range of functions can be extended with additional
components and accessories.
Intended use presupposes that a fixed installation in
conjunction with permissible, system-specific compo-
nents has been carried out.
Commercial or industrial usage for a purpose other
than central heating/cooling or DHW heating shall be
deemed inappropriate.
Incorrect use and/or operation of the appliance (e.g.
the appliance being opened by the system user) is pro-
hibited and will result in an exclusion of liability. Incor-
rect use also occurs if the components in the heating
system are modified from their intended function.
Note
The Vitocal 300-G Pro must be operated exclusively
by authorised and trained personnel.
Product information
Vitocal 300-G Pro
Heat pump Vitocal 300-G Pro, type BW
Medium Brine/water
Single stage heat pumps 301.C090
301.C120
Two-stage heat pumps 302.C090
302.C110
302.C140
302.C180
302.C230
Characteristics:
■Integral heat pump control unit Vitotronic 200,
type WO1C
■The refrigerant circuit has an electronic expansion
valve (EEV) with an independent control circuit
(refrigerant circuit controller).
■The heat pump control unit can switch and regulate
one cooling circuit. The cooling circuit may be a
heating circuit prepared on site for cooling operation
or a separate cooling circuit.
■All sensors are fitted inside sensor wells.
■Electric booster heaters (on site) can be controlled
(e.g. instantaneous heating water heater, immersion
heater in heating water buffer cylinder).
An output increase in connection with additional
Vitocal 300-G Pro appliances (cascade) is possible.
Information
Intended use (cont.)
5787 232 GB
Information

10
■Electrical connection of system components
(pumps, mixers, valves, message facilities, contac-
tors, function extensions, sensors etc.):
Connections are made inside the heat pump wiring
chamber. Observe information from page 31.
■Power supply:
The number of power cables from the meter box to
the heat pump wiring chamber depends on the sys-
tem version and tariffs used. Observe information
from page 45.
Transport and siting requirements
■The Vitocal 300-G Pro is delivered as a standard
unit. Side panels are packed separately for fitting on
site. See pages 23 to 25.
■The programming unit of the Vitotronic 200 is deliv-
ered loose inside the wiring chamber and must be fit-
ted and connected on site. See page 49.
■Accessories are delivered separately.
■No charging with oil or refrigerant required. The heat
pump has been charged with oil and refrigerant at
the factory.
Unloading and handling
Note
Before unloading, have the recipient check the con-
signment for possible damage. Note down any dam-
age on the delivery note and notify the haulage con-
tractor.
■Lifting gear, such as slings and cross beams, must
be provided on site.
■The lifting capacity of each sling and that of the cross
beam must be at least equal to the shipping weight.
See "Specification".
■Only use suitable equipment for unloading the lorry;
see the following chapter.
!Please note
To prevent appliance damage, observe the fol-
lowing when unloading and handling the heat
pump.
■Never put weight on top of the appliance.
■To protect the paintwork, wrap the lifting gear
(such as ropes, cross beams) and place pad-
ding between the heat pump and lifting gear.
■Observe correct weight distribution when lift-
ing. Due to the heat exchangers, the heat
pump's centre of gravity is at the back, by the
hydraulic connections.
■Avoid impact and shocks to prevent damage
to the internal pipework of the heat pump.
■To protect the refrigerant circuit, avoid strongly
tilting the compressor: tilting angle of the heat
pump max. 30°.
Viessmann (Switzerland) AG accepts no liability for
any damage resulting from incorrect handling.
Preparing for installation
General information on electrical connection
5787 232 GB
Installation

11
Handling by crane
Fig. 1
ALifting shackle attachment points
BBelt strap suitable for the weight (see page 12)
CEdge protection (e.g. 2 or 3 layers of corrugated
cardboard)
DCross beam to relieve the load on the frame
Note
Lifting with belt straps is only permitted without fitted
side, front or back panels.
Handling by forklift truck or pallet truck
Fig. 2
Information regarding transport with fork lift truck
■Select a fork length appropriate for the total heat
pump length; see "Specification" from page 80.
■The heat pump's centre of gravity is at the back,
close to the hydraulic connections.
■Observe required edge protection (e.g. 2 or 3 layers
of corrugated cardboard).
Note
Transport by fork lift truck is only permitted without fit-
ted side, front and back panels.
Preparing for installation
Transport and siting requirements (cont.)
5787 232 GB
Installation

12
Installation room requirements
!Please note
Unfavourable ambient conditions can lead to
malfunctions and appliance damage.
■The installation room must be dry and free
from the risk of frost.
■Ensure ambient temperatures between 0 and
35 °C.
Danger
Dust, gases and vapours can be damaging to
health and trigger explosions.
Avoid dust, gases and vapours in the installation
room.
!Please note
Overloading the floor can result in damage to
the building structure.
Observe the permissible floor load. Take the
weight of the appliance into account.
Weight
Type Weight in kg
BW 301.C090 770
BW 301.C120 870
BW 302.C090 720
BW 302.C110 910
BW 302.C140 1180
BW 302.C180 1280
BW 302.C230 1425
■To prevent the transmission of structure-borne noise,
never site the appliance above ceilings with wooden
joists (e.g. in the attic).
■Level the appliance horizontally.
Where floors are uneven, distribute the load evenly
across the adjustable feet.
■Observe minimum room volume (to EN 378).
Note
Additional, country-specific regulations apply.
Minimum room volume, based on the available
air volume
Type Minimum room volume
in m3
BW 301.C090 36
BW 301.C120 40
BW 302.C090 34
BW 302.C110 38
BW 302.C140 56
BW 302.C180 72
BW 302.C230 94
■Observe the floor area and minimum clearances
(see following chapter).
Preparing for installation
Transport and siting requirements (cont.)
5787 232 GB
Installation

13
Minimum clearances
1 heat pump
600 600
Fig. 3
Heat pump cascade (2 to 5 heat pumps)
600 600 600
Fig. 4
ACable entries:
On-site strain relief fittings required (wall clearance
≥ 80 mm)
B■When using hydraulic connection accessories
(connection set and Victaulic flange adaptor set,
2½" or 3"):
≥ 1000 mm
■On-site hydraulic connections:
≥ 600 mm
CClearances for installation and maintenance:
≥ 500 mm
DWithout anti-vibration parts (side sections):
≥ 855 mm
Preparing for installation
Transport and siting requirements (cont.)
5787 232 GB
Installation

14
Anti-vibration base
Site the heat pump on a base prepared on site for the
purpose of noise attenuation and even weight distribu-
tion.
Note
In the case of corner installation, enlarge the base by
the minimum clearances (see chapter "Minimum clear-
ances" on page 13).
150
Fig. 5
AConcrete B25, iron
BFloor construction, screed
CTop edge unfinished floor
DImpact sound insulation as per regulations
EPressure-tested sound insulation layer, approx.
10 to 20 mm
FHeat pump
Pressure points of the adjustable heat pump feet
Type BW 301.C090, BW 301.C120, BW 302.C090 and BW 302.C110
168
1400
1064
1000
50
709
50
145,5
Fig. 6
êPressure point, adjustable foot
EPressure-tested sound insulation layer, approx.
10 to 20 mm
FFront of the heat pump
Preparing for installation
Transport and siting requirements (cont.)
5787 232 GB
Installation

15
Type BW 302.C140, BW 302.C180 and BW 302.C230
2040
852 800
1000
50
709
50
194
145,5
Fig. 7
êPressure point, adjustable foot
EPressure-tested sound insulation layer, approx. 10
to 20 mm
FFront of the heat pump
Requirements for on-site connections
Dimensions Vitocal 300-G
Type BW 301.C090 to BW 301.C120, BW 302.C090 and BW 302.C110
850
1343
1650
911
1241
644
436
1126
368 343200
Fig. 8
A Flow, primary circuit (inlet):
Victaulic 3" (DN 80)
B Flow, secondary circuit (outlet):
Victaulic 2½" (DN 65)
C Return, primary circuit (outlet):
Victaulic 3" (DN 80)
D Return, secondary circuit (inlet):
Victaulic 2½" (DN 65)
ELow voltage < 50 V
FPower supply 230 V/50 Hz
GPower supply 400 V/50 Hz
Preparing for installation
Transport and siting requirements (cont.)
5787 232 GB
Installation

16
Note
The width of the heat pump is indicated with and with-
out side panels. The dimensions without side panels
are the transport dimensions.
Type BW 302.C140 to BW 302.C230
1241
644
436
1126
368 343
200
911
1932
1650
850
Fig. 9
A Flow, primary circuit (inlet):
Victaulic 3" (DN 80)
B Flow, secondary circuit (outlet):
Victaulic 2½" (DN 65)
C Return, primary circuit (outlet):
Victaulic 3" (DN 80)
D Return, secondary circuit (inlet):
Victaulic 2½" (DN 65)
ELow voltage < 50 V
FPower supply 230 V/50 Hz
GPower supply 400 V/50 Hz
Note
The width of the heat pump is indicated with and with-
out side panels. The dimensions without side panels
are the transport dimensions.
Hydraulic connection requirements
■Make on-site hydraulic connections stress-free.
■Make the hydraulic connections between several
heat pumps on site.
■All components required for the cooling circuit must
be provided on site. This must be achieved with an
appropriately sized plate heat exchanger.
Preparing for installation
Requirements for on-site connections (cont.)
5787 232 GB
Installation

17
Primary circuit: brine/water, 1-stage (type BW 301C.090 and BW 301.C120)
Hydraulic installation scheme
22
27
20
21
1
P1
P1
2
--KM BUS--
--230 V--
--F2--
--211.1-- --F3--
--224.2--
--2/211.1--
15
--LP1 X3.8;3.9--
--2/LP1 X3.8;3.9--
P
Fig. 10
Required equipment
Pos. Description
1Heat pump
2Heat pump control unit
qT Primary pump (fail-safe)
wP Brine safety assembly
wQ Pressure switch, primary circuit
wW Brine manifold for geothermal probes/collectors
wU Geothermal probes
Note
If 2 primary pumps are used, at least 75 % of the nomi-
nal flow rate must be produced during partial load.
Electrical installation scheme
For a summary of electrical connections, see from
page 31 and separate "Connection and wiring dia-
gram".
Preparing for installation
Hydraulic connection requirements (cont.)
5787 232 GB
Installation

18
Primary circuit: brine/water, 2-stage (type BW 302.C090, BW 302.C110,
BW 302.C140, BW 302.C180 and BW 302.C230)
Hydraulic installation scheme
22
27
20
21
1
15
--2/211.1--
P1
25
--2/224.2--
P1
2
--KM BUS--
--230 V--
--F2--
--211.1-- --F3--
--224.2--
--LP1 X3.8;3.9--
--2/LP1 X3.8;3.9--
P
Fig. 11
Required equipment
Pos. Description
1Heat pump
2Heat pump control unit
qT Primary pump 1 (fail-safe)
wP Brine safety assembly
wQ Pressure switch, primary circuit
wW Brine manifold for geothermal probes/collectors
wT Optionally: 2nd primary pump (fail-safe) for stage 2
Note
■Contactor relay required.
■Size primary pump 1 qT for partial load.
wU Geothermal probes
Electrical installation scheme
For a summary of electrical connections, see from
page 31 and separate "Connection and wiring dia-
gram".
Preparing for installation
Hydraulic connection requirements (cont.)
5787 232 GB
Installation

19
Primary circuit: brine/water, heat pump cascade (type BW 301.C090 to BW 302.C230)
Hydraulic installation scheme
22
27
20
21
9
P1
25
P1
P1
15
2
--KM BUS--
--230 V--
--F2--
--211.1-- --F3--
--2/211.1--
--2/211.1--
P1
1
2
--KM BUS--
--230 V--
--F2--
--211.1-- --F3--
--LP1 X3.8;3.9--
--LP1 X3.8;3.9--
--2/LP1 X3.8;3.9--
P
Fig. 12
Equipment required
Pos. Description
1Lead heat pump
2Heat pump control unit with LON communication module (accessories)
9Lag heat pump
qT Primary pump, lead heat pump (fail-safe)
Note
For 2-stage Vitocal 300-G Pro, a primary pump can be used for stages 1 and 2 respectively. Ob-
serve minimum flow rate.
wP Brine safety assembly
wQ Pressure switch, primary circuit
wW Brine manifold, geothermal probes/collectors
wT Primary pump, lag heat pump (fail-safe)
Note
For 2-stage Vitocal 300-G Pro, a primary pump can be used for stages 1 and 2 respectively.
wU Geothermal probes
Electrical installation scheme
For a summary of electrical connections, see from
page 31 and separate "Connection and wiring dia-
gram".
Preparing for installation
Hydraulic connection requirements (cont.)
5787 232 GB
Installation

20
Heat pump cascade: 1-stage/2-stage (type BW 301.C090 to BW 302.C230)
A heat pump cascade consists of a lead heat pump
and lag heat pumps.
Each lag heat pump has a heat pump control unit.
Both the lead and lag heat pumps can have 2 stages.
The lead heat pump regulates the operation of the
heat pumps within the cascade.
■Up to 4 lag heat pumps possible when connected via
LON.
The following communication modules (accessories)
must be fitted in the heat pump control units:
–LON cascade communication module in the lead
heat pump
–LON communication module in lag heat pumps
Hydraulic installation scheme
IV III II I
Fig. 13
AInterface to heating water buffer cylinder
(return)
CInterface to the separate cooling circuit or heat-
ing/cooling circuit
HInterface to heating water buffer cylinder (flow)
PInterface to primary circuit (flow)
QInterface to primary circuit (return)
WInterface to the DHW cylinder
I Lead heat pump in the heat pump cascade
(1-stage or 2-stage)
II to IV Lag heat pump in the heat pump cascade
(1-stage or 2-stage respectively)
Equipment required
Pos. Description
Heat generator
1Heat pumps
2Heat pump control unit
3Outside temperature sensor
4LON communication module for cascade control of the lead heat pump I
LON communication module for lag heat pumps II to IV
5Secondary pump 1 (fail-safe)
6Circulation pump for cylinder heating (fail-safe)
Preparing for installation
Hydraulic connection requirements (cont.)
5787 232 GB
Installation