Nibe VVM 500 User guide

Installer manual
Indoor module
NIBE VVM 500
IHB EN 2235-1
731222

Quick guide
Navigation Ok button (confirm/select)
Back button (back/undo/exit)
Control knob (move/increase/reduce)
A detailed explanation of the button functions can be found on page 37.
How to scroll through menus and make different settings is described on page 39.
Set the indoor climate
2X
MY INSTALLATION
INDOOR CLIMATE HOT WATER
INFO
The mode for setting the indoor temperature is accessed by pressing the OK button twice, when in the start mode in
the main menu.
Increase hot water volume
2X
1X INDOOR CLIMATE HOT WATER
MY INSTALLATION INFO
To temporarily increase the amount of hot water, first turn the control knob to mark menu 2 (water droplet) and then
press the OK button twice.

41 Important information
4Safety information
4Symbols
4Marking
4Serial number
5Recovery
5Inspection of the installation
6Outdoor modules
72 Delivery and handling
7Transport
7Assembly
8Supplied components
9Removing panels
103 Design VVM 500
11List of components
124 Pipe connections
12General pipe connections
15Dimensions and pipe connections
16Connecting air/water heat pump
16Connection during use without heat pump
16Climate system
16Cold and hot water
16Installation alternative
185 Electrical connections
18General
21Connections
25Settings
26Optional connections
30Connecting accessories
316 Commissioning and adjusting
31Preparations
31Filling and venting
32Start-up and inspection
34Setting the heating curve
35Cooling in 2-pipe system
35Setting hot water circulation
35Pool
35SG Ready
377 Control - Introduction
37Display unit
37Menu system
418 Control – Menus
41Menu 1 - INDOOR CLIMATE
42Menu 2 - HOT WATER
42Menu 3 - INFO
43Menu 4 - MY SYSTEM
44Menu 5 - SERVICE
539 Service
53Service actions
5610 Disturbances in comfort
56Info-menu
56Manage alarm
56Troubleshooting
58Electrical addition only
5911 Accessories
6112 Technical data
61Dimensions
62Technical specifications
63Electrical circuit diagram
68Item register
71Contact information
3Table of ContentsNIBE VVM 500
Table of Contents

Safety information
This manual describes installation and service procedures
for implementation by specialists.
The manual must be left with the customer.
This appliance can be used by children
aged from 8 years and above and per-
sons with reduced physical, sensory or
mental capabilities or lack of experience
and knowledge if they have been given
supervision or instruction concerning use
of the appliance in a safe way and under-
stand the hazards involved. Children shall
not play with the appliance. Cleaning and
user maintenance shall not be made by
children without supervision.
This is an original manual. It may not be
translated without the approval of NIBE.
Rights to make any design or technical
modifications are reserved.
©NIBE 2022.
MinMaxSystem pres-
sure
0.05 MPa
(0.5 bar)
0.3 MPa
(3 bar)
Heating medium
0.01 MPa
(0.1 bar)
1.0 MPa
(10 bar)
Domestic water
Water may drip from the safety valve’s
overflow pipe. The overflow pipe must be
routed to a suitable drain, so hot water
splashes cannot cause harm. The entire
length of the overflow pipe must be inclined
to prevent water pockets, and must also be
frost-proof. The overflow pipe must be at
least the same size as the safety valve. The
overflow pipe must be visible and its mouth
must be open and not placed close to elec-
trical components.
VVM 500 must be installed via an isolator
switch. The cable area has to be dimen-
sioned based on the fuse rating used.
Symbols
Explanation of symbols that may be present in this manual.
NOTE
This symbol indicates danger to person or machine.
Caution
This symbol indicates important information about
what you should consider when installing or servi-
cing the installation.
TIP
This symbol indicates tips on how to facilitate us-
ing the product.
Marking
Explanation of symbols that may be present on the product’s
label(s).
Danger to person or machine.
!
Read the User Manual.
Serial number
The serial number can be found at the bottom right of the
front cover, in the info menu (menu 3.1) and on the type
plate (PZ1).
Serial number
Caution
You need the product’s (14 digit) serial number for
servicing and support.
NIBE VVM 500Chapter 1 | Important information4
Important information

Recovery
Leave the disposal of the packaging to the installer
who installed the product or to special waste sta-
tions.
Do not dispose of used products with normal
household waste. It must be disposed of at a special waste
station or dealer who provides this type of service.
Improper disposal of the product by the user results in ad-
ministrative penalties in accordance with current legislation.
Inspection of the installation
Current regulations require the heating installation to be inspected before it is commissioned. The inspection must be
carried out by a suitably qualified person.
In addition, fill in the page for the installation data in the User Manual.
DateSignatureNotesDescription
✔
Heating medium, see section "System diagram"
System flushed
System vented
Expansion vessel
Particle filter
Safety valve
Shut off valves
System pressure
Connected according to outline diagram
Hot water, see section "Cold and hot water"
Shut off valves
Mixing valve
Safety valve
Electricity, see section "Electrical connections"
Connected communication
Fuses, indoor module
Fuses property
Outside sensor
Room sensor
Current sensor
Safety breaker
Earth circuit-breaker
Setting of emergency mode thermostat
Miscellaneous
Docked to
5Chapter 1 | Important informationNIBE VVM 500

Outdoor modules
COMPATIBLE AIR/WATER HEAT PUMPS
F2040
F2040-16
Part no. 064 108
F2040-12
Part no. 064 092
F2050
F2050-10
Part no. 064 318
F2050-6
Part no. 064 328
F2120
F2120-20 3x400V
Part no. 064 141
F2120-16 3x400V
Part no. 064 139
S2125
S2125-8 3x400V
Part no. 064 219
S2125-8 1x230V
Part no. 064 220
S2125-12 3x400V
Part no. 064 217
S2125-12 1x230V
Part no. 064 218
F2300
F2300-20
Part no. 064 064
NIBE SPLIT HBS 05
HBS 05-12
Part no. 067 480
AMS 10-12
Part no. 064 110
HBS 05-16
Part no. 067 536
AMS 10-16
Part no. 064 035
NIBE SPLIT
HBS 20-6
Part no. 067 668
AMS 20-6
Part no. 064 235
HBS 20-10
Part no. 067 819
AMS 20-10
Part no. 064 319
Check the software version of compatible older NIBE
air/water heat pumps, see page 17.
NIBE VVM 500Chapter 1 | Important information6

Transport
VVM 500 should be transported and stored vertically in a
dry place.
However, the VVM 500 can be carefully laid on its back when
being moved into a building.
R
0
R
0
Assembly
•Place VVM 500 on a solid foundation indoors that can take
its weight.
Use the product’s adjustable feet to attain a horizontal
and stable set-up.
30 - 50 mm
30 - 50 mm
15 - 40 mm
20-55 mm
•The space where VVM 500 is located must be frost-free.
•Because water can exit the safety valve1for hot water,
when connected to VVM 500, the space where VVM 500
is placed must be provided with a floor drain.
1Not enclosed.
INSTALLATION AREA
Leave a free space of 800 mm in front of the product. All
service on VVM 500 can be carried out from the front.
800
10-25
50
50
NOTE
Leave 10 – 25 mm free space between VVM 500
and the wall behind for routing cables and pipes.
7Chapter 2 | Delivery and handlingNIBE VVM 500
Delivery and handling

Supplied components
Room sensorOutside sensor
O-rings
LEK
LEK
LEK
Current sensor
LEK
Cable*
APH
Flow meter*
Union nut*
Copper pipe with flange to
energy meter*
*Only applies to Norway.
LOCATION
The kit of supplied items is placed on top of the product.
NIBE VVM 500Chapter 2 | Delivery and handling8

Removing panels
FRONT PANEL
1
2
LEK
LEK
LEK
LEK
LEK
1. Remove the screws from the lower edge of the front
panel.
2. Lift the panel out at the bottom edge and up.
SIDE PANELS
LEK
LEK
LEK
The side panels can be removed to make installation easier.
Caution
50 mm space required to remove the side panels.
1. Remove the screws from the upper and lower edges.
2. Twist the panel slightly outwards.
3. Move the panel backwards and slightly to the side.
4. Pull the panel to one side.
5. Pull the panel forwards.
6. Assembly takes place in the reverse order.
9Chapter 2 | Delivery and handlingNIBE VVM 500

APH
VVM 500
AA3
QM1
AA1
EB1
FQ10
FC1
QN35
PZ3PZ1
GP12
QN10
AA2
SF1
UB1
AA4-XF4
AA4
AA4-XF3
GP1
BT63
BT2
UB2
XL8
XL9
XL4
XL30
XL2
XL3
XL14
XL13XL19
XL18XL1
QN11
BT6
BT54
QM20
BT7
PZ3
PZ1
XL39
XL39
XL18
XL14
XL19
XL13
AA7
W130
BT3
NIBE VVM 500Chapter 3 | Design VVM 50010
Design VVM 500

List of components
PIPE CONNECTIONS
Connection, heating medium flow lineXL1
Connection, heating medium return lineXL2
Connection, cold waterXL3
Connection, hot waterXL4
Connection, docking from heat pumpXL8
Connection, docking to heat pumpXL9
Connection, solar heating system supply lineXL13
Connection, solar heating system return lineXL14
Connection, docking in high tempXL18
Connection, docking out high tempXL19
Connection, expansion vesselXL30
Connection, docking poolXL39
HVAC COMPONENTS
Circulation pumpGP1
Charge pumpGP12
Drain valve, climate systemQM1
Venting valve, climate systemQM20
Reversing valve, climate system/water heating, flow
line
QN10
Mixing valve, additionQN11
Reversing valve, climate system/water heating, return
line
QN35
SENSORS ETC.
Temperature sensors, heating medium flowBT2
Temperature sensor, heating medium return1 BT3
Temperature sensor, hot water, control1 BT6
Temperature sensor, hot water, display1 BT7
Temperature sensor, solar coil1 BT54
Temperature sensor, heating medium supply after immer-
sion heater
BT63
1Not visible in the image
ELECTRICAL COMPONENTS
Immersion heater cardAA1
Base cardAA2
Input circuit boardAA3
Display unitAA4
AA4-XF3 USB socket
AA4-XF4 Service socket
Extra relay circuit boardAA7
Immersion heaterEB1
Miniature circuit-breakerFC1
Temperature limiterFQ10
SwitchSF1
Network cable for NIBE UplinkW130
MISCELLANEOUS
Rating platePZ1
Serial number platePZ3
Cable glandUB1
Cable glandUB2
Designations according to standard EN 81346-2.
11Chapter 3 | Design VVM 500NIBE VVM 500

General pipe connections
Pipe installation must be carried out in accordance with
current norms and directives.
NOTE
The heating medium side and the domestic hot
water side must be fitted with the necessary
safety equipment in accordance with the applic-
able regulations.
The pipe dimension should not be less than the recommen-
ded pipe diameter according to the table. However, each
system must be dimensioned individually to manage the
recommended system flows.
MINIMUM SYSTEM FLOWS
The installation must be dimensioned to manage at least
the minimum defrosting flow at 100% pump operation, see
table.
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
22200.29AMS 10-12/
HBS 05-12
28250.39AMS 10-16/
HBS 05-16
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
22200.19
AMS 20-6/
HBS 20-6
AMS 20-10/
HBS 20-10
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
22200.29F2040-12
28250.39F2040-16
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
22200.19
F2050-6
F2050-10
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
28250.38
F2120-16
(3x400V)
35320.48
F2120-20
(3x400V)
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
28250.32
S2125-8
(1x230V)
S2125-8
(3x400V)
S2125-12
(1x230V)
S2125-12
(3x400V)
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
35320.47F2300-20
NOTE
An undersized system can result in damage to the
product and lead to malfunctions.
VVM 500 together with a compatible air/water heat pump
(see section "Outdoor modules") constitutes a complete in-
stallation for heating and hot water.
The system requires the dimensions of the radiator circuit
to be designed for a low temperature heating medium. At
the lowest dimensioned outdoor temperature, the highest
recommended temperatures are 55 °C on the supply line
and 45 °C on the return line, but VVM 500 can handle up to
70 °C on the supply line.
NIBE recommends installing VVM 500 as close to the heat
pump as possible for the optimum comfort. For further in-
formation about the location of various components, see
section "Installation alternative" in this manual.
Caution
Ensure that incoming water is clean. When using
a private well, it may be necessary to supplement
with an extra water filter.
NIBE VVM 500Chapter 4 | Pipe connections12
Pipe connections

Caution
Any high points in the climate system, must be
equipped with air vents.
NOTE
The pipe systems need to be flushed out before
the indoor module is connected so that any debris
cannot damage component parts.
NOTE
Water may drip from the safety valve’s overflow
pipe. The overflow pipe must be routed to a suit-
able drain, so hot water splashes cannot cause
harm. The entire length of the overflow pipe must
be inclined to prevent water pockets, and must
also be frost-proof. The overflow pipe must be at
least the same size as the safety valve. The over-
flow pipe must be visible and its mouth must be
open and not placed close to electrical compon-
ents.
NOTE
Switch (SF1) must not be moved to "" or " " until
VVM 500 has been filled with water. Otherwise the
temperature limiter, thermostat and the immersion
heater etc can be damaged.
SYSTEM VOLUME
H
Internal volume in VVM 500 for
calculating expansion vessel is
500 l. The expansion vessel's
volume must be at least 5 % of
the system's total volume.
Example table
Volume (l) ex-
pansion vessel
Total volume (l)
(indoor module
and climate sys-
tem)
25500
35700
501,000
NOTE
Expansion vessels are not supplied with the
product. Equip the product with an expansion
vessel.
The pre-pressure of the pressure expansion vessel must be
dimensioned according to the maximum height (H) between
the vessel and the highest positioned radiator, see figure.
A pre-pressure of 0.5 bar (5 mvp) means a maximum permit-
ted height difference of 5 m.
If the standard pre-pressure in the pressure vessel is not
high enough, it can be increased by filling via the valve in
the expansion vessel. The expansion vessel’s pre-pressure
must be entered in the check list on page 5.
Any change in the initial pressure affects the ability of the
expansion vessel to handle the expansion of the water.
13Chapter 4 | Pipe connectionsNIBE VVM 500

SYMBOL KEY
MeaningSymbol
Shut-off valve
Non-return valve
Mixing valve
Circulation pump
Immersion heater
Expansion vessel
Filterball
Flow meter/energy meter
Shut off valve
Pressure gauge
Control valve
Safety valve
Reversing valve/shunt
Manual reversing valve/shunt
Under floor heating systems
Indoor module
Cooling system
Air/water heat pump
Radiator system
Domestic hot water
Hot water circulation
SYSTEM DIAGRAM
VVM 500 consists of a hot water coil, immersion heater,
circulation pumps, buffer vessel, control system and is pre-
pared for use with solar panels. VVM 500 connects to the
climate system.
VVM 500 is directly adapted for connection and communic-
ation with a compatible NIBE air/water heat pump, see sec-
tion "Outdoor modules", and together they constitute a
complete heating installation.
When it is cold outdoors, the air/water heat pump works
with VVM 500, and if the outdoor air temperature falls below
the heat pump’s stop temperature, all heating is carried out
by VVM 500.
XL 4
39 2
13
14
38 9 30 1 18
19
NIBE VVM 500Chapter 4 | Pipe connections14

Dimensions and pipe
connections
19
28
43
1788
691
725
791
900
734
756
66
85
382
760
296
154
73
61
57
660
381
290
648
25-50
19
28
43
1788
691
725
791
900
734
756
66
85
382
760
296
154
73
61
57
660
381
290
648
25-50
XL8 XL9
XL4
XL2
XL3XL1
XL30
Pipe connections
G25 intXL1 Connection, heating medium supply line
G25 intXL2 Connection, heating medium return line
G25 intXL3 Connection, cold water
G25 ext.XL4 Connection, hot water
G25 intXL8 Connection, docking from heat pump
G25 intXL9 Connection, docking to heat pump
G25 intXL30 Connection, expansion vessel
15Chapter 4 | Pipe connectionsNIBE VVM 500

Connecting air/water heat pump
You can find a list of compatible air/water heat pumps in
section "Compatible air/water heat pumps".
Caution
Also, consult the Installer Manual for your air/water
heat pump.
Install as follows:
•pressure relief valve
Some heat pump models have a factory-fitted safety
valve.
•drain valve
For draining the heat pump during prolonged power fail-
ures. Only for heat pumps that do not have a gas separat-
or.
•non-return valve
A non-return valve is only required in those installations
where the placement of the products in relation to each
other can cause self-circulation.
If the heat pump is already fitted with a non-return valve,
there is no need to install another.
•shut-off valve
To facilitate any future servicing.
•filterball or particle filter
Installed before connection "heating medium return" (XL2)
(the lower connection) on the vacuum pump.
In installations with a particle filter, the filter is combined
with an additional shut-off valve.
EB101-XL1
EB101-XL2
XL8
XL9
Connection during use without
heat pump
Connect the pipe for docking in from the heat pump (XL8)
with the pipe out to the heat pump XL9.
XL8
XL9
Climate system
A climate system is a system that regulates the indoor
temperature with the help of the control system in VVM 500
and, for example, radiators, underfloor heating, underfloor
cooling, fan coils, etc.
CONNECTING THE CLIMATE SYSTEM
Install as follows:
•expansion vessel in connection XL30
•pressure gauge in connection XL30
•pressure relief valve
Recommended opening pressure is 0.25 MPa (2.5 bar).
For information about max opening pressure, see technical
data. Install the safety valve as illustrated.
•shut-off valves
Install the shut-off valves as close to VVM 500 as possible.
•When connecting to a system with thermostats on all ra-
diators/underfloor heating coils, either a bypass valve
must be fitted or some of the thermostats must be re-
moved to ensure there is sufficient flow and heat emission.
P
XL1
XL2
XL30
Cold and hot water
The settings for hot water are made in menu 5.1.1.
CONNECTING COLD AND HOT WATER
Install as follows:
•shut-off valve
•non-return valve
•pressure relief valve
The safety valve must have a maximum 1.0 MPa (10.0 bar)
opening pressure and be installed on the incoming domest-
ic water line as shown.
•mixing valve
A mixer valve must also be installed, if the factory setting
for hot water is changed. National regulations must be
observed.
XL3
XL4
Installation alternative
VVM 500 can be installed in several different ways, some of
which are shown here.
NIBE VVM 500Chapter 4 | Pipe connections16

Further option information is available at nibe.eu and in the
respective assembly instructions for the accessories used.
See page 59 for a list of the accessories that can be used
with VVM 500.
COMPATIBLE NIBE AIR/WATER HEAT PUMPS
Compatible NIBE air/water heat pump must be equipped
with a control board with a display with the minimum soft-
ware version indicated in the following list. The version of
the control board is displayed in the heat pump’s display (if
applicable) at start-up.
Software versionProduct
118F2020
55F2025
55F2026
all versionsF2030
all versionsF2040
all versionsF2120
55F2300
all versionsS2125
all versionsNIBE SPLIT HBS 05:
AMS 10-6 + HBS 05-6
AMS 10-8 + HBS 05-12
AMS 10-12 + HBS 05-12
AMS 10-16 + HBS 05-16
all versionsNIBE SPLIT HBS 20:
AMS 20-6 + HBS 20-6
EXTRA HOT WATER HEATERS
The system can be supplemented with an extra water
heater, if a large bath tub or other significant consumer of
hot water is installed. A mixer valve is then installed on the
outgoing hot water from the water heater.
Water heater with immersion heater
In a water heater with an immersion heater, the water is
initially heated by the heat pump. The immersion heater in
the water heater is used for keeping warm and when the
heat pump does not have sufficient power.
The water heater’s flow is connected after VVM 500.
EXTRA CLIMATE SYSTEM
In buildings with several climate systems that require differ-
ent supply temperatures, the accessory ECS 40/ECS 41 can
be connected.
A shunt valve then lowers the temperature to the underfloor
heating system, for example.
-EP21-RM1
-EP21-GP10-EP21-BT2
-EP21-AA25
-EP21-BT3
-EP21-QN25
-EP21
CONNECTING HOT WATER CIRCULATION
A circulation pump can be controlled by VVM 500 to circulate
the hot water. The circulating water must have a temperat-
ure that prevents bacterial growth and scalding, and national
standards must be satisfied.
The HWC return is connected to a freestanding water heater.
The circulation pump is activated via AUX input in menu 5.4.
-QZ1-FQ3
-QZ1-GP11-QZ1-RM1-QZ1-RN1
-QZ1
17Chapter 4 | Pipe connectionsNIBE VVM 500

General
All electrical equipment, except the outdoor sensors, room
sensors and the current sensors are ready connected at the
factory.
•Disconnect the indoor module before insulation testing
the house wiring.
•If the building is equipped with an earth-fault breaker,
VVM 500 should be equipped with a separate one.
•For electrical wiring diagram for VVM 500, see section
"Electrical circuit diagram".
•Communication and sensor cables to external connections
must not be laid close to high current cables.
•The minimum area of communication and sensor cables
to external connections must be 0.5 mm² up to 50, for
example EKKX or LiYY or equivalent.
•When cable routing in VVM 500, cable grommets UB1and
UB2, (marked in image) must be used. In UB1 and UB2, the
cables are inserted through the indoor module from the
back to the front.
APH
VVM500
B
AB
APH
UB2
UB1
SF1
NOTE
The switch (SF1) must not be set to "" or " " until
the boiler has been filled with water and the radi-
ator system vented. Otherwise the temperature
limiter, thermostat and the immersion heater can
be damaged.
NOTE
If the supply cable is damaged, only NIBE, its ser-
vice representative or similar authorised person
may replace it to prevent any danger and damage.
NOTE
Electrical installation and service must be carried
out under the supervision of a qualified electrician.
Cut the current with the circuit breaker before
carrying out any servicing. Electrical installation
and wiring must be carried out in accordance with
the stipulations in force.
Wilo
VVM320
AA1
FQ10
FC1
FQ10-S2
MINIATURE CIRCUIT-BREAKER
The indoor module and a large proportion of its internal
components are internally fused by a miniature circuit
breaker (FC1).
NIBE VVM 500Chapter 5 | Electrical connections18
Electrical connections

TEMPERATURE LIMITER
The temperature limiter (FQ10) cuts the power supply to the
electric additional heat, if the temperature rises to between
90 and 100 °C and it is reset manually.
Resetting
The temperature limiter (FQ10) is accessible behind the front
cover. Reset the temperature limiter by pressing the button
(FQ10-S2) using a small screwdriver. Press the button lightly,
max. 15 N (approx. 1.5 kg).
LEK
LEK
LEK
LEK
LEK
FQ10
FQ10-S2
ACCESSIBILITY, ELECTRICAL CONNECTION
The plastic cap of the electrical boxes is opened using a
screwdriver.
NOTE
The cover for the input card is opened without a
tool.
Removing the cover, input circuit board
1
2
1. Push the catch down.
2. Angle out the cover and remove it.
Removing the cover, immersion heater circuit
board
1
2
A
B
1. Insert the screwdriver (A) and pry the catch carefully
downwards (B).
2. Angle out the cover and remove it.
Removing the cover, base board
Caution
To remove the cover for the base board, the cover
for the input circuit board must first be removed.
1
A
B
2
1. Insert the screwdriver (A) and pry the catch carefully
downwards (B).
2. Angle out the cover and remove it.
19Chapter 5 | Electrical connectionsNIBE VVM 500

CABLE LOCK
Use a suitable tool to release/lock cables in the indoor
module terminal blocks.
LEK
1
1
2
2
3
3
1
2
3
3
4
1
2
LEK
1
1
2
2
3
3
1
2
3
3
4
1
2
1
2
NIBE VVM 500Chapter 5 | Electrical connections20