Viessmann AC-Box Operating instructions

Installation and service instructions
for contractors
VIESMANN
AC-Box
Pre-assembled unit for implementing the natural cooling and active cooling
functions in conjunction with brine/water heat pumps up to 17 kW
For applicability, see the last page
AC-Box
5675 895 GB 2/2015 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
5675 895 GB

3
1. Information Symbols ................................................................................................. 4
Product information ................................................................................ 4
■Information regarding operation ......................................................... 5
2. Preparing for installation Hydraulic function diagram .................................................................... 6
Hydraulic connection with on-site pipework ........................................... 7
Hydraulic connection with AC-Box connection accessories .................. 7
Siting and transport requirements .......................................................... 8
■Transport ............................................................................................ 8
■Installation room requirements ........................................................... 8
■Minimum clearances ........................................................................... 8
3. Installation sequence Siting the AC-Box .................................................................................. 9
Hydraulic connection ............................................................................. 9
■Connection with AC-Box connection accessories .............................. 10
■Installing the contact humidistat 24 V– (accessories) ......................... 11
Electrical connection .............................................................................. 11
■Required connections ......................................................................... 11
■Additional connections ........................................................................ 12
■Overview of electrical connections ..................................................... 15
■Switching to heat pump control unit (NC / AC signal) ......................... 16
■Shutdown signal for heat pump 230 V~ .............................................. 16
■Contact humidistat 24 V– .................................................................... 18
■Additional frost stat (accessories) ....................................................... 18
■Contact humidistat signal 24 V– ......................................................... 19
Power supply ......................................................................................... 19
■Connections on plug fÖ ...................................................................... 20
Closing the AC-Box ............................................................................... 20
4. Upkeep Internal components .............................................................................. 21
5. Parts lists Overview of assemblies ......................................................................... 22
■Parts not shown .................................................................................. 23
Casing .................................................................................................... 24
Electrical equipment .............................................................................. 26
Hydraulics .............................................................................................. 28
Connection set ....................................................................................... 30
6. Connection and wiring dia-
gram
.................................................................................................................. 32
7. Specification .................................................................................................................. 33
8. Declaration of conformity .................................................................................................................. 34
9. Keyword index .................................................................................................................. 35
Index
Index
5675 895 GB

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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.
Product information
Design and function
The AC-Box includes all hydraulic and electrical com-
ponents required for cooling a heating/cooling circuit
without mixer or a separate cooling circuit in conjunc-
tion with a brine/water heat pump. Subject to the cool-
ing demand, either the natural cooling or the active
cooling function starts.
In natural cooling mode, the temperature level of the
primary circuit is directly transferred to the cooling cir-
cuit. In active cooling mode, the compressor starts. As
a result, the available cooling capacity is significantly
higher compared to natural cooling.
Hydraulic connections
The heating/cooling circuit or the separate cooling cir-
cuit and the primary circuit (brine) are hydraulically
connected directly to the AC-Box. The hydraulic con-
nection between the heat pump and the AC-Box can
be made on site or via the AC-Box connection acces-
sories.
Electrical connection
The AC-Box and the heat pump are connected electri-
cally. The electrical cables and power cable required
are connected inside the AC-Box at the factory and
routed outside through the back of the appliance.
Information
Symbols
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Information

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Product validity
The AC-Box can be used in conjunction with the fol-
lowing heat pumps:
■Vitocal 300-G, types BW/BWC 301.A06 to A17
■Vitocal 300-G, types BW/BWC 301.B06 to B17
■Vitocal 350-G, type BW/BWC 351.A07
Information regarding operation
■In order to safeguard the transfer of the cooling
capacity at all times, we recommend connecting fan
convectors to the AC-Box.
■If cooling by means of an underfloor heating system,
a contact humidistat is required: See page 11.
Information
Product information (cont.)
5675 895 GB
Information

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M
M
M
M
M
M
M
A
S
O
P R
V
W
B
C
D
E
F
G
H
K
LM
UT
N
Fig.1
Note
■Valve switching states without switching by the heat
pump.
■Component layout inside the appliance: See
page 21.
Direction of flow, 3-way diverter valve
Valve open
Valve closed
A2-way valve V1
B2-way valve V2
C2-way valve V3
D2-way valve V7
E2-way valve V5
F2-way valve V6
G3-way diverter valve V4
HHigh efficiency circulation pump M2
KHigh efficiency circulation pump M1
LPlate heat exchanger 1
MPlate heat exchanger 2
NFrost stat
OAC-Box
PContact humidistat 24 V– (accessories)
RFlow, heating/cooling circuit or separate cooling
circuit
SReturn, heating/cooling circuit or separate cool-
ing circuit
TGeothermal probe
UHeat pump
VDHW cylinder flow
WDHW cylinder return
Switching states of the integral 2-way valves and circulation pumps
Active signal V1 AV2 BV3 CV5 EV6 FV7 DM1 KM2 H
None 0 0
NC signal \ 0
AC signal \ \
Valve open
Valve closed
\ON
0OFF
Preparing for installation
Hydraulic function diagram
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Installation

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If the AC-Box cannot be installed immediately to the
left of the heat pump:
1. Install the AC-Box near the heat pump.
2. Connect on-site connection lines so that they are
free of load and torque stress.
Hydraulic connection with AC-Box connection accessories
The AC-Box connection accessories comprise 4 ther-
mally insulated connecting pipes, each with 1 air vent
valve and gaskets.
10
Fig.2
AAC-Box
BPrimary circuit connection line: AC-Box brine inlet
CPrimary circuit connection line: AC-Box brine outlet
DPrimary circuit flow: AC-Box brine outlet
EPrimary circuit return: AC-Box brine inlet
FFlow, heating/cooling circuit or separate cooling
circuit
GReturn, heating/cooling circuit or separate cooling
circuit
HSecondary circuit connection line: AC-Box heating
water outlet
KSecondary circuit connection line: AC-Box heating
water inlet
LSecondary circuit connection line: Heat pump
heating water inlet
MDHW cylinder flow
NSecondary circuit connection line: Heat pump
heating water outlet
PPrimary circuit connection line: Heat pump brine
inlet
Preparing for installation
Hydraulic connection with on-site pipework
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Installation

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RPrimary circuit connection line: Heat pump brine
outlet
SHeat pump
Siting and transport requirements
Transport
!Please note
Impacts, compression and tensile loads can
cause damage to the outside panels of the
appliance.
Never apply loads/weight to the top, front or
side panels of the appliance.
Installation room requirements
!Please note
Unfavourable ambient conditions can lead to
malfunction 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 cause 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
total weight of the appliance into account.
Minimum clearances
A B
200
400400
1500
Fig.3
AAC-Box
BHeat pump
Preparing for installation
Hydraulic connection with AC-Box connection… (cont.)
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Installation

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1. Site the AC-Box on a level surface, to the left of the
heat pump with no gap between them: See Figs. 2
and 3.
2. Level the appliance with its adjustable feet.
Hydraulic connection
To prevent corrosion damage, provide all hydraulic
pipes with thermal insulation as vapour diffusion-proof
installation (on the brine and cold water sides) in
accordance with current engineering standards.
Installation sequence
Siting the AC-Box
5675 895 GB
Installation

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Connection with AC-Box connection accessories
1.
4x
2.
4.
2x
5.
2x
3.
2x
2x
Fig.4
Note
Thermally insulate the connections of the AC-Box and
the heat pump with vapour diffusion-proof adhesive
tape.
A to DHydraulic connection lines: See the following
table
Installation sequence
Hydraulic connection (cont.)
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Installation

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Tightening torques for fitting the union nuts
Connection to Primary circuit hydraulic connection lines Secondary circuit hydraulic connection
lines
A B C D
Heat pump 70 Nm 70 Nm 70 Nm 70 Nm
AC-Box 50 Nm 50 Nm — —
Installing the contact humidistat 24 V– (accessories)
The contact humidistat monitors the formation of con-
densate on the flow of the heating/cooling circuit or of
the separate cooling circuit.
■Where the heating/cooling circuit extends over sev-
eral rooms with different relative humidity levels, it
may become necessary to provide several contact
humidistats.
■Where several contact humidistats are used, connect
all contact humidistats electrically in series.
■In the delivered condition, the contact humidistat
switches at a relative humidity of 80 %. This value
can be adjusted.
Contact humidistat installation instructions
Installation conditions: The flow and return of the heat-
ing/cooling circuit or the separate cooling circuit are
connected to the AC-Box.
1. Fit the contact humidistat outside the AC-Box to the
flow of the heating/cooling circuit or the separate
cooling circuit as near as possible to the room to be
monitored.
2. Thermally insulate all lines on site with vapour diffu-
sion-proof material. Thermally insulate the pipe
joints and the area around the contact humidistat
with vapour diffusion-proof insulating tape.
Electrical connection
Danger
Damaged wiring insulation wiring can lead to
serious injury from electrical current and result in
appliance damage.
Route cables so that they cannot touch very hot,
vibrating or sharp-edged components.
Danger
Incorrect wiring can lead to serious injury from
electrical current and result in appliance dam-
age.
Take the following measures to prevent drifting
of wires into the adjacent voltage area:
■Route LV leads < 42 V separately from cables
> 42 V/230 V~/400 V~ and secure with cable
ties.
■Only strip the minimum of insulation from
cables as close as possible to the terminals
and bundle tightly to the corresponding termi-
nals.
■If 2 components are connected to the same
terminal, press both cores together in a single
wire ferrule.
Danger
Incorrect wire assignment can result in serious
injury and damage to the appliance.
Never interchange cores "L" and "N".
Colour coding to IEC 60757
L BN Brown
N BU Blue
?GNYE Green/yellow
Required connections
The connecting cables are factory-fitted with plugs for
connection to the AC-Box PCB; their free ends are
routed outside through the back panel. The PCB is
located in the control panel behind the front panel.
Note
Observe the cable markers: See the following table.
Installation sequence
Hydraulic connection (cont.)
5675 895 GB
Installation

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The free ends have been stripped of their insulation
and have wire ferrules fitted and are therefore ready
for connection.
Existing connecting cables
Designation Function Internal connec-
tion, plug
Page
"NC signal" Switching signal 230 V~ for switching the AC-Box for the natu-
ral cooling function
aMAD 16
"AC signal" Switching signal 230 V~ for switching the AC-Box for the ac-
tive cooling function
aMAE 16
"SC" ■Shutdown signal for heat pump if safety equipment has re-
sponded, e. g. contact humidistat 24 V– and/or frost stat
■The shutdown signal is part of the heat pump safety chain.
aMG 16
"Mains" Power supply 1/N/PE 230 V/50 Hz fÖ 19
Additional connections
To connect the following components, insert the con-
necting cables into the AC-Box, where they must be
routed accordingly:
■Contact humidistat 24 V– (accessories)
■Additional frost stat (accessories)
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Removing the front panel and side panel
3x
1.
2.
Fig.5
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Inserting and routing cables
For the additional components, use the two cable
entries which are still available at the back of the AC-
Box.
2.
1.
A B
3.
Fig.6
AAdditional frost stat 230 V~ (accessories)
BContact humidistat 24 V– (accessories)
1. Remove the dummy plugs, insert cables and apply
threaded strain relief fittings (on site).
2. Secure the cables with cable ties to the holes at the
top of the angled panel.
3. Route cables into the terminal box, apply strain
relief fittings and connect:
■Connect the cable of the additional frost stat to
plug aBAB on the AC-Box PCB: See page 18.
Remove the jumper from plug aBAB.
■Connect the 24 V– contact humidistat cable
across terminals X4.1 and X4.2 on the AC-Box
PCB: See page 18. Remove the jumper from
plug aBAC.
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Overview of electrical connections
1
2
3
4
5
6
7
8
9
X4
230 V~
aMG fÖ
aBY]
A
aBY]
B
aMY]
DaMY]
E
L N
230 V~
X2
X1
2V7
s-]
BlM]
GlM]
FlM]
E
V6
V5
s-]
AlM]
DlM]
ClM]
BlM]
A
1
V4
V3 V1
V2
aBY]
C
Fig. 7 AC-Box PCB
AaMAD
NC signal 230 V~: See page 16.
BaMAE
AC signal 230 V~: See page 16.
CaMG
Shutdown signal for heat pump 230 V~: See
page 16.
DfÖ
Power supply 230 V~: See page 19.
EMessage output if contact humidistat 24 V–
has responded:
Floating changeover contact, contact breaking
capacity 10 to 30 V, 5 A
FContact humidistat 24 V–, 10 mA: See
page 18.
GaBAC
If contact humidistat 24 V– is connected to F,
remove the jumper.
HaBAB
Additional frost stat (accessories): Remove
jumper when connecting.
KFrost stat connected at the factory
X1, X2 Terminal strip for valves and circulation pumps
connected at the factory
X4 Low voltage terminal strip
Note
If several contact humidistats are used, the switching
contacts must be connected as N/C contacts and in
series.
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Switching to heat pump control unit (NC / AC signal)
4
N
?
3
2
1N N N N
1? ? ?
123
X6
X1
X2
123
sYÖsYAsYSsYD
4 1235
F
12
171D
1
2
GNYE
171E
1
2
GNYE
BU BN BU BN
A
?
ED
C
B
Fig.8
Note
Plugs aMAD and aMAE are plugged into the AC-Box
PCB at the factory.
AAC-Box PCB
B"AC signal" connecting cable
C"NC Signal" connecting cable
DHeat pump control unit Vitotronic 200
ECross connect PCB
X1 Earth conductor terminal strip
X2 Neutral conductor terminal strip
FMain PCB (function components 230 V~)
Shutdown signal for heat pump 230 V~
The frost stat and contact humidistat 24 V– are con-
nected to the AC-Box. The shutdown signal must be
connected at the heat pump control unit to ensure the
compressor stops when these safety devices respond.
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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175
1 2
BN
GNYE
BU
1
2
3
4
5
6
7
8
9
10
11
12
X3
A
L
L´
X1
B
C
Fig.9
Note
Plug aMG is plugged into the AC-Box PCB at the fac-
tory.
ACross connect PCB inside the heat pump control
unit
X1 Earth conductor terminal strip
X3 Terminal strip for message and safety connec-
tion
BAC-Box PCB
C"SC" connecting cable
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Contact humidistat 24 V–
Note
If several contact humidistats are used, the switching
contacts must be connected as N/C contacts and in
series.
2
3
4
5
6
7
8
9
X4.1
1
42
A
Fig.10
AContact humidistat (accessories) 24 V–, 10 mA
X4 Low voltage terminal strip on the AC-Box PCB
1. Connect the contact humidistat.
2. Remove the jumper from plug aBAC: See page 15.
Additional frost stat (accessories)
151B
12
A
Fig.11
AFrost stat
Contact breaking capacity 230 V~, 8 A
1. Connect the frost stat.
2. Remove the jumper from plug aBAB: See page 15.
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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Contact humidistat signal 24 V–
If a contact humidistat has responded, this response
can be made available as a signal via a floating
changeover contact.
X4.8
X4.9
X4.7
[YA
K
Fig.12
X4 Low voltage terminal strip on the AC-Box PCB,
contact breaking capacity 10 to 30 V, 5 A
X4.7 Contact humidistat has responded.
X4.9 Contact humidistat has not responded.
Power supply
Isolators for non-earthed conductors
■Install an isolator in the power cable to provide
omnipolar separation from the mains for all active
conductors, corresponding to overvoltage category
III (3 mm) for full isolation. This isolator must be fitted
in the permanent electrical installation in line with
installation requirements, e.g. mains isolator or
upstream circuit breaker.
■We additionally recommend installing an AC/DC-
sensitive RCD (RCD class B ) for DC (fault)
currents that can occur with energy efficient equip-
ment.
■Class A RCDs must not be used and not installed
upstream of the class B RCD.
Connection information
■The "Mains" power cable is connected to the AC-Box
PCB and routed to the outside of the unit at the fac-
tory.
■We recommend connecting the power supply for the
AC-Box at the power supply of the heat pump control
unit.
Connection to the same fuse provides additional pro-
tection in the case of faults and when the power is
switched off. For this, take the power consumption of
the connected consumer into account (fuse protec-
tion, heat pump control unit, max. 16 A).
Heat pump installation and service instructions
Danger
Incorrect electrical installations can lead to seri-
ous injury from electrical current and result in
appliance damage.
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
■Protect the power cable with a fuse/MCB of
max. 16 A.
Danger
The absence of system component earthing can
lead to serious injury from electrical current and
component damage in the event of an electrical
fault.
The appliance and pipework must be connected
to the equipotential bonding of the building.
Danger
Incorrect core assignment can lead to serious
injury from electrical current and result in equip-
ment damage.
Never interchange cores "L" and "N".
Colour coding to IEC 60757
L BN Brown
N BU Blue
?GNYE Green/yellow
Installation sequence
Electrical connection (cont.)
5675 895 GB
Installation

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L1
NfÖ
F
A
B
C
D
E
Fig.13
AAC-Box PCB
BPower distribution board (on-site)
CHeat pump control unit
DMains isolator (optional)
EFuse F1 (max. 16 A)
FPower supply 1/N/PE 230 V/50 Hz
Connections on plug fÖ
40
NL
N
L1
A
BU
GNYE
BN
Fig.14
APower cable 1/N/PE 230 V/50 Hz
■Length approx. 2.5 m
■Connected to the AC-Box at the factory via
plug fÖ and routed to the outside; marked
"Mains"
Closing the AC-Box
Fit in reverse order to Fig. 5 on page 13.
Installation sequence
Power supply (cont.)
5675 895 GB
Installation