Nibe F1255 Series User guide

Installer manual
LEK
NIBE™ F1255
Ground source heat pump
IHB GB 1617-3
331296

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 38.
How to scroll through menus and make different settings is described on page 40.
Set the indoor climate
2X
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
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.
In event of disturbances in comfort
If a disturbance in comfort of any type occurs there are some measures that can be taken before you need to
contact your installer. See page 59 for instructions.

Table of Contents
41 Important information
4Safety information
72 Delivery and handling
7Transport
7Assembly
8Supplied components
8Removing the covers
9Removing parts of the insulation
103 The heat pump design
10General
12Distribution boxes
13Cooling section
154 Pipe connections
15General
16Dimensions and pipe connections
16Brine side
17Heating medium side
17Water heater
17Docking alternatives
205 Electrical connections
20General
22Connections
24Settings
27Optional connections
31Connecting accessories
326 Commissioning and adjusting
32Preparations
32Filling and venting
33Start guide
34Post adjustment and venting
36Setting the cooling/heating curve
387 Control - Introduction
38Display unit
39Menu system
428 Control - Menus
42Menu 1 - INDOOR CLIMATE
42Menu 2 - HOT WATER
42Menu 3 - INFO
43Menu 4 - HEAT PUMP
44Menu 5 - SERVICE
539 Service
53Service actions
5910 Disturbances in comfort
59Info menu
59Manage alarm
59Troubleshooting
6111 Accessories
6312 Technical data
63Dimensions and setting-out coordinates
64Technical specifications
70Energy labelling
81Index
3Table of Contents |NIBE™ F1255

Safety information
This manual describes installation and service procedures
for implementation by specialists.
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.
Rights to make any design or technical
modifications are reserved.
©NIBE 2016.
Symbols
NOTE
This symbol indicates danger to machine or
person.
Caution
This symbol indicates important information
about what you should observe when maintain-
ing your installation.
TIP
This symbol indicates tips on how to facilitate
using the product.
Marking
The CE marking means that NIBE ensures that the
product meets all regulations that are placed on it based
on relevant EU directives. The CE mark is obligatory for
most products sold in the EU, regardless where they are
made.
Serial number
The serial number can be found at the bottom right of
the front cover and in the info menu (menu 3.1).
You can also find the serial number on the type plate
PF1, for location see the section for the Heat pump
design in the installer manual.
Serial number
Caution
Always give the product's serial number (14 di-
gits) when reporting a fault.
Recovery
Leave the disposal of the packaging to the in-
staller who installed the product or to special
waste stations.
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
administrative penalties in accordance with current legis-
lation.
Country specific information
Installer manual
This installer manual must be left with the customer.
NIBE™ F1255Chapter 1 | Important information4
1 Important information

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
✔
Brine (page 16)
System flushed
System vented
Antifreeze
Level/Expansion vessel
Particle filter
Safety valve
Shut off valves
Circulation pump setting
Heating medium (page 17)
System flushed
System vented
Expansion vessel
Particle filter
Safety valve
Shut off valves
Circulation pump setting
Electricity (page 20)
Connections
Main voltage
Phase voltage
Fuses heat pump
Fuses property
Outside sensor
Room sensor
Current sensor
Safety breaker
Earth circuit-breaker
Setting of emergency mode thermostat
5Chapter 1 | Important informationNIBE™ F1255

Contact information
KNV Energietechnik GmbH, Gahberggasse 11, 4861 SchörflingAT
Tel: [phone] Fax: [phone] E-mail: [e-mail] www.knv.at
NIBE Wärmetechnik c/o ait Schweiz AG, Industriepark, CH-6246 AltishofenCH
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.nibe.ch
Druzstevni zavody Drazice s.r.o, Drazice 69, CZ - 294 71 Benatky nad JizerouCZ
Tel: [phone] Fax: [phone] E-mail: [email protected] www.nibe.cz
NIBE Systemtechnik GmbH, Am Reiherpfahl 3, 29223 CelleDE
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.nibe.de
Vølund Varmeteknik A/S, Member of the Nibe Group, Brogårdsvej 7, 6920 VidebækDK
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.volundvt.dk
NIBE Energy Systems OY, Juurakkotie 3, 01510 VantaaFI
Puh: 09-274 697 0 Fax: [phone] E-mail: inf[email protected] www.nibe.fi
NIBE Energy Systems France Sarl, Zone industrielle RD 28, Rue du Pou du Ciel, 01600 ReyrieuxFR
Tel : [phone] Fax : [phone] E-mail: inf[email protected] www.nibe.fr
NIBE Energy Systems Ltd, 3C Broom Business Park, Bridge Way, Chesterfield S41 9QGGB
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.nibe.co.uk
NIBE Energietechniek B.V., Postbus 634, NL 4900 AP OosterhoutNL
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.nibenl.nl
ABK AS, Brobekkveien 80, 0582 Oslo, Postadresse: Postboks 64 Vollebekk, 0516 OsloNO
Tel. sentralbord: [phone] E-mail: [email protected] www.nibeenergysystems.no
NIBE-BIAWAR Sp. z o. o. Aleja Jana Pawła II 57, 15-703 BIAŁYSTOKPL
Tel: [phone] Fax: [phone] E-mail: [e-mail] www.biawar.com.pl
© "EVAN" 17, per. Boynovskiy, Nizhny NovgorodRU
Tel./fax [phone] E-mail: [email protected] www.nibe-evan.ru
NIBE AB Sweden, Box 14, Hannabadsvägen 5, SE-285 21 MarkarydSE
Tel: [phone] Fax: [phone] E-mail: inf[email protected] www.nibe.se
For countries not mention in this list, please contact Nibe Sweden or check www.nibe.eu for more information.
NIBE™ F1255Chapter 1 | Important information6

Transport
F1255 should be transported and stored vertically in a
dry place. When being moved into a building, F1255
may be leant back 45 °.
Caution
The product can be tail heavy.
Remove the outer panels in order to protect them when
moving in confined spaces inside buildings.
R
0
+2
0
-2
1
R
0
HMflow 49(50)°C
Hotwater
51°C
+2
0
-2
1
R
0
HMflow
49(50)°C
Hotwater
51°C
R
0
Pulling out the cooling module
To simplify transport and service, the heat pump can be
separated by pulling the cooling module out from the
cabinet.
See page 55 for instructions about the separation.
Assembly
■Position F1255 on a solid foundation that tolerates
the weight of the heat pump. Use the product's ad-
justable feet to obtain a horizontal and stable set-up.
30 - 50 mm
30 - 50 mm
15 - 40 mm
■Because water comes from F1255, the area where the
heating pump is located must be equipped with floor
drainage.
■Install with its back to an outside wall, ideally in a room
where noise does not matter, in order to eliminate
noise problems. If this is not possible, avoid placing it
against a wall behind a bedroom or other room where
noise may be a problem.
■Wherever the unit is located, walls to sound sensitive
rooms should be fitted with sound insulation.
■Route pipes so they are not fixed to an internal wall
that backs on to a bedroom or living room.
Installation area
Leave free space of 800 mm in front of the product. Ap-
prox. 50 mm free space is required on each side (see
image) in order to remove the side panels. The panels
do not need to be removed during service. All service on
F1255 can be carried out from the front. Leave space
between the heat pump and the wall behind (and any
routing of supply cables and pipes), to reduce the risk of
transmission of any vibrations.
(50) (50)
800
*
*
* A normal installation needs 300 – 400 mm (any side) for connec-
tion equipment, i.e. level vessel, valves and electrical equipment.
7Chapter 2 | Delivery and handlingNIBE™ F1255
2 Delivery and handling

Supplied components
Enclosed in all countries:
O-ringsRoom sensorOutside sensor
8 x1 x1 x
Compression ring couplings
F1255 6 kW
2 x (ø28 x G25)
2 x (ø22 x G20)
F1255 12/16 kW
4 x (ø28 x G25)
In other countries the following
is also enclosed:
In the DACH coun-
tries and Italy, the
following is also en-
closed:
LEK
LEK
LEK
LEK
Level vessel
1 x
Current sensor
3 x (not
1x230V)
WILO
LEK
LEK
WILO
WILO
2,5(22)
H- 50 - 2,5
TUV-SV-97-525
WILO
LEK
LEK
WILO
WILO
2,5(22)
H- 50 - 2,5
TUV-SV-97-525
LEK
Particle filter
F1255 6 kW
1 x G1
1 x G3/4
F1255 12/16
kW
1 x G1
1 x G1 1/4
Safety valve
(0.3 MPa) (3
bar)
1 x
Shut off valve
with filter
F1255 6 kW
1 x G1
1 x G3/4
F1255 12/16
kW
1 x G1
1 x G1 1/4
Location
The kit of supplied items is placed in packaging on top
of the heat pump.
Removing the covers
Front cover
1
2
LEK
LEK
LEK
LEK
LEK
1. Remove the screws from the lower edge of the front
cover.
2. Lift the cover out at the bottom edge and up.
Side covers
LEK
LEK
LEK
The side covers can be removed to facilitate the installa-
tion.
1. Remove the screws from the upper and lower edges.
2. Twist the cover slightly outward.
3. Move the hatch outwards and backwards.
4. Assembly takes place in the reverse order.
NIBE™ F1255Chapter 2 | Delivery and handling8

Removing parts of the
insulation
Parts of the insulation can be removed to facilitate the
installation.
Insulation, top
1. Disconnect the cable from the motor and remove
the motor from the shuttle valve as illustrated.
LEK
LEK
A
B
LEK
2. Grip the handle and pull straight out as illustrated.
LEK
Insulation, immersion heater
NOTE
Electrical installation and service must be carried
out under the supervision of a qualified electri-
cian. Electrical installation and wiring must be
carried out in accordance with the stipulations
in force.
1. Remove the cover for the junction box according to
the description on page 20.
2. Grip the handle and pull the insulation carefully to-
wards you as illustrated.
LEK
9Chapter 2 | Delivery and handlingNIBE™ F1255

General
F1255
BT7
QN10
BT2
EB1
UB1
QM34
BT6
UB2
QM32
QM33
XL1
XL6 XL7
XL4 XL3 XL2
PF1
PF2
QM22
UB3
AA4
W130
QM31
AA4-XJ3
AA4-XJ4
SF1
RA3
XL4 XL3
FR1
View from above
XL5 BT7
View from behind
BF1
NIBE™ F1255Chapter 3 | The heat pump design10
3 The heat pump design

Pipe connections
Connection, heating medium flowXL1
Connection, heating medium returnXL2
Connection, cold waterXL3
Connection, hot waterXL4
Connection, HWC*XL5
Connection, brine inXL6
Connection, brine outXL7
* Only heat pumps with enamelled or stainless steel vessel.
HVAC components
Venting, coilQM22
Shut-off valve, heating medium flowQM31
Shut off valve, heating medium returnQM32
Shut off valve, brine outQM33
Shut-off valve, brine inQM34
Shuttle valve, climate system/water heaterQN10
Sensors etc.
Flow meter**BF1
Outdoor temperature sensor*BT1
Temperature sensors, heating medium flowBT2
Temperature sensor, hot water chargingBT6
Temperature sensor, hot water topBT7
**Only heat pumps with energy meter
* Not illustrated
Electrical components
Display unitAA4
AA4-XJ3 USB socket
AA4-XJ4 Service outlet (No function)
Immersion heaterEB1
Sacrificial anode*FR1
Choke**RA3
SwitchSF1
Network cable for NIBE UplinkTM W130
* Only heat pump with enamelled vessel.
** Only for F1255-12 kW 3X400V.
Miscellaneous
Rating platePF1
Type plate, cooling sectionPF2
Cable gland, incoming electricityUB1
Cable glandUB2
Cable gland, rear side, sensorUB3
Designations in component locations according to
standard IEC 81346-1 and 81346-2.
11Chapter 3 | The heat pump designNIBE™ F1255

Distribution boxes
AA3
AA2
FD1
AA1
FA1
AA8
AA23
RA3
RA2
Electrical components
Immersion heater cardAA1
Base cardAA2
Input circuit boardAA3
Sacrificial anode card*AA8
Communication boardAA23
Miniature circuit-breakerFA1
Temperature limiter/Emergency mode thermostatFD1
Choke**RA2
Choke**RA3
* Only heat pump with enamelled vessel.
** Only for F1255-12 kW 3X400V.
Designations in component locations according to
standard IEC 81346-1 and 81346-2.
NIBE™ F1255Chapter 3 | The heat pump design12

Cooling section
1X230V, 3X230V, 3X400V, 6 kW
LEK LEK
BT10
AA100
BT3
QM2
GP1
GP2
QM1
BT11
BT12
1X230V, 3X230V, 12 kW
LEK
BT10
AA100
BT3
QM2
GP1
GP2
QM1
BT11
BT12
3X400V, 12 kW
LEK
BT10
AA100
BT3
QM2
GP1
GP2
QM1
BT11
BT12
RF2
3X400V, 16 kW
LEK
BT10
AA100
BT11
BT12
GP1
GP2
QM2
RF2
QM1 BT3
1X230V, 3X230V, 3X400V, 6 kW
LEK LEK
EP2
BT14
QA40
BP2
BT15
BP1 EB10
BT17
EP1
GQ10
HS1
XL20
QN1
XL21
RA1
CA1
1X230V, 3X230V, 12 kW
LEK
EP2 BT17
QA40
BT15
BP1
BT14
EP1
GQ10
HS1
XL20
QN1
XL21
RA1
CA1 BP2
EB10
3X400V, 12 kW
LEK
EP2
BT17
QA40
BT15
BP1
BT14
EP1
GQ10
HS1
XL20
QN1
BP2
EB10
XL21
3X400V, 16 kW
LEK
EP2
BT14
BT17
EP1
BP2
BT15
BP1
GQ10
HS1
XL20
QN1
EB10 XL21
QA40
13Chapter 3 | The heat pump designNIBE™ F1255

Pipe connections
Service connection, high pressureXL20
Service connection, low pressureXL21
HVAC components
Circulation pumpGP1
Brine pumpGP2
Drainage, climate systemQM1
Draining, brine sideQM2
Sensors etc.
High pressure pressostatBP1
Low pressure pressostatBP2
Temperature sensors, heating medium returnBT3
Temperature sensor, brine inBT10
Temperature sensor, brine outBT11
Temperature sensor, condenser supply lineBT12
Temperature sensor, hot gasBT14
Temperature sensor, fluid pipeBT15
Temperature sensor, suction gasBT17
Electrical components
Joint cardAA100
CapacitorCA1
Compressor heaterEB 10
InverterQA40
ChokeRA1
EMC-filterRF2*
* Only 12 & 16 kW 3X400 V.
Cooling components
EvaporatorEP1
CondenserEP2
CompressorGQ10
Drying filterHS1
Expansion valveQN1
Designations in component locations according to
standard IEC 81346-1 and 81346-2.
NIBE™ F1255Chapter 3 | The heat pump design14

General
Pipe installation must be carried out in accordance with
current norms and directives. F1255 can operate with a
return temperature of up to 58 °C and an outgoing
temperature from the heat pump of 70 (65 °C with only
the compressor).
F1255 is not equipped with external shut off valves; these
must be installed to facilitate any future servicing.
Caution
Any high points in the climate system, must be
equipped with air vents.
NOTE
The pipe system needs to be flushed out before
the heat pump is connected so that debris can-
not damage component parts.
Symbol key
MeaningSymbol
Venting valve
Shut-off valve
Non-return valve
Level vessel
Trim valve
Shunt / shuttle valve
Safety valve
Temperature sensor
Expansion vessel
Pressure gauge
P
Circulation pump
Particle filter
Auxiliary relay
Flow meter (only heat pumps with energy
meter)
Compressor
Heat exchanger
System diagram
F1255 consists of a heat pump, water heater, electrical
module, circulation pumps and a control system. F1255
is connected to the brine and heating medium circuits.
In the heat pump evaporator, the brine (water mixed
with anti-freeze, glycol or ethanol) releases its energy to
the refrigerant, which is vaporised in order to be com-
pressed in the compressor. The refrigerant, of which the
temperature has now been raised, is passed to the con-
denser where it gives off its energy to the heating medi-
um circuit and, if necessary, to the water heater. If there
is a greater need for heating/hot water than the com-
pressor can provide there is an integrated immersion
heater.
VVKV
KBinVBf VBr KBut
XL1 XL6 XL7XL4 XL3 XL2
Connection, heating medium flowXL 1
Connection, heating medium returnXL 2
Connection, cold waterXL 3
Connection, hot waterXL 4
Connection, brine inXL 6
Connection, brine outXL 7
15Chapter 4 | Pipe connectionsNIBE™ F1255
4 Pipe connections

Dimensions and pipe
connections
620
600
560 440
70
1775
650*
25-50
25
50
130
210
390
470
525
650*
620
600
560 440
70
1775
650*
25-50
25
50
130
210
390
470
525
650*
XL1 XL6 XL7XL4 XL3 XL2
Pipe dimensions
16
kW
12
kW
6
kW
Connection
2822(mm)(XL1)/(XL2) Heating medium
flow/return ext Ø
22(mm)(XL3)/(XL4) Cold/hot water Ø
28(mm)(XL6)/(XL7) Brine in/out ext Ø
Brine side
Collector
Caution
The length of the collector hose varies depend-
ing on the rock/soil conditions, climate zone
and on the climate system (radiators or under-
floor heating) and the heating requirement of
the building Each installation must be sized in-
dividually.
Max length per coil for the collector should not exceed
400 m.
In those cases where it is necessary to have several col-
lectors, these should be connected in parallel with the
possibility for adjusting the flow of the relevant coil.
For surface soil heat, the hose should be buried at a
depth determined by local conditions and the distance
between the hoses should be at least 1 metre.
For several bore holes, the distance between the holes
must be determined according to local conditions.
Ensure the collector hose rises constantly towards the
heat pump to avoid air pockets. If this is not possible,
airvents should be used.
As the temperature of brine system can fall below 0 °C
it must be protected against freezing down to -15 °C. 1
litre of ready mixed brine per meter of collector hose
(applies when using PEM-hose 40x 2.4 PN 6.3) is used as
a guide value when making the volume calculation.
Side connection
It is possible to angle the brine connections, for connec-
tion to the side instead of top connection.
To angle out a connection:
1. Disconnect the pipe at the top connection.
2. Angle the pipe in the desired direction.
3. If necessary, cut the pipe to the desired length.
Connecting the brine side
■Insulate all indoor brine pipes against condensation.
■The level vessel must be installed at the highest point
in the brine system, on the incoming pipe before the
brine pump (Alt. 1).
If the level vessel cannot be placed at the highest point,
an expansion vessel must be used (Alt. 2).
NOTE
Note that condensation may drip from the level
vessel. Position the vessel so that this does not
harm other equipment.
■Details of the antifreeze used must be shown on the
level vessel.
* Can be angled for side connection.
NIBE™ F1255Chapter 4 | Pipe connections16

■Install the enclosed safety valve under the level vessel
as illustrated. The entire length of the overflow water
pipe from the safety valve must be inclined to prevent
water pockets and must also be frost-free.
■Install shut off valves as close to the heat pump as
possible.
■Fit the supplied particle filter on the incoming pipe.
In the case of connection to an open groundwater sys-
tem, an intermediate frost-protected circuit must be
provided, because of the risk of dirt and freezing in the
evaporator. This requires an extra heat exchanger.
P
P
XL6
XL7
Collector
Alt. 1 Alt. 2
Heating medium side
Connecting the climate system
A climate system is a system that regulates indoor com-
fort with the help of the control system in F1255 and for
example radiators, underfloor heating/cooling, fan
convectors etc.
■Install all required safety devices, shut-off valves (as
close to the heat pump as possible), and supplied
particle filter.
■The safety valve must have a maximum opening pres-
sure of 0.25 MPa (2.5 bar) and be installed on the
heating medium return as illustrated. The entire length
of the overflow water pipe from the safety valve must
be inclined, to prevent water pockets and must also
be frost-free.
■When connecting to a system with thermostats on all
radiators, a relief valve must be fitted, or some of the
thermostats must be removed to ensure sufficient flow.
P
P
XL1 XL4 XL3 XL2
Water heater
Connecting the hot water heater
■The hot water heater in the heat pump must be sup-
plied with necessary set of valves.
■The mixing valve must be installed if the setting is
changed so that the temperature can exceed 60 °C.
■The setting for hot water is made in menu 5.1.1.
■The safety valve must have a maximum opening pres-
sure of 1.0 MPa (10.0 bar) and be installed on the in-
coming domestic water line as illustrated. The entire
length of the overflow water pipe from the safety valve
must be inclined to prevent water pockets and must
also be frost-free.
Docking alternatives
F1255 can be connected in several different ways, some
of which are shown below.
Further option information is available at www.nibe.eu
and in the respective assembly instructions for the ac-
cessories used. See page 61 for a list of the accessories
that can be used with F1255.
Buffer vessel
If the climate system volume is too small for the heat
pump output, the radiator system can be supplemented
with a buffer vessel, for example NIBE UKV.
UKV
P
17Chapter 4 | Pipe connectionsNIBE™ F1255

Extra electric hot water heater
The heat pump should be supplemented with an electric
water heater, for example NIBE COMPACT, if a whirlpool
or other significant consumer of hot water is installed.
■The valve connection on COMPACT can be separated.
The mixing valve remains on COMPACT and the remain-
ing valve connector can be used for incoming cold
water in F1255.
VV
KV
COMPACT
CW
HW
Ground water system
An intermediate heat exchanger is used to protect the
heat pump's exchanger from dirt. The water is released
into a buried filtration unit or a drilled well. See page 30
for more information about connecting a ground water
pump.
If this docking alternative is used, "min. brine out" in
menu 5.1.7 "br pmp al set." must be changed to a suit-
able value to prevent freezing in the heat exchanger.
Ventilation recovery
The installation can be supplemented with the exhaust
air module FLM to provide ventilation recovery.
■Pipes and other cold surfaces must be insulated with
diffusion-proof material to prevent condensation.
■The brine system must be supplied with a pressure
expansion vessel (CM3). If there is a level vessel (CM2)
this should be replaced.
Frånluft
Ø 160
Avluft
Ø 160
P
Extract air
Exhaust
air
FLM
Free cooling
The installation can be supplemented with fan con-
vectors, for example, in order to allow connections for
free cooling (PCS 44).
■Pipes and other cold surfaces must be insulated with
diffusion-proof material to prevent condensation.
■Where the cooling demand is high, fan convectors
with drip trays and drain connection are needed.
■The brine system must be supplied with a pressure
expansion vessel (CM3). If there is a level vessel (CM2)
this should be replaced.
P
Fläktkonvektor
3
2
1
Fan convectors
NIBE™ F1255Chapter 4 | Pipe connections18

Under floor heating systems
The external circulation pump is dimensioned for the
under floor heating system’s demand.
To ensure a heating supply during hot water production,
the heating system can be supplemented with a NIBE
UKV vessel, e.g. when there is a water coil in the FTX
ventilation.
UKV
P
UKV
Two or more climate systems
When more than one climate system, with a lower tem-
perature, is to be heated up, the following connection
can be used. The shunt valve lowers the temperature to,
for example, the under floor heating system.
The ECS 40/ECS 41 accessory is required for this connec-
tion.
Pool
Charging of the pool is controlled by the pool sensor. In
the case of low pool temperatures, the shuttle valve re-
verses direction and opens towards the pool exchanger.
The POOL 40 accessory is required for this connection.
Pool
19Chapter 4 | Pipe connectionsNIBE™ F1255

General
All electrical equipment, except the outdoor sensors,
room sensors and the current sensors are ready connec-
ted at the factory.
■Disconnect the heat pump before insulation testing
the house wiring.
■If the building is equipped with an earth-fault breaker,
F1255 should be equipped with a separate one.
■If a miniature circuit breaker is used this should have
at least motor characteristic “C”. See page 64 for fuse
size.
■Electrical wiring diagrams for the heat pump, see sep-
arate installation handbook for electrical wiring dia-
grams.
■Communication and sensor cables to external connec-
tions 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 m, for example EKKX or LiYY or equivalent.
■When cable routing in F1255, cable grommets (e.g.
UB1-UB3, marked in image) must be used. In UB1-UB3
the cables are inserted through the heat pump from
the back to the front.
NOTE
The switch (SF1) must not be moved to "" or
" " until the boiler has been filled with water.
Component parts of the product can be dam-
aged.
NOTE
Electrical installation and service must be carried
out under the supervision of a qualified electri-
cian. Cut the current with the circuit breaker
before carrying out any servicing. Electrical in-
stallation and wiring must be carried out in ac-
cordance with the stipulations in force.
NOTE
Check the connections, main voltage and phase
voltage before the machine is started, to prevent
damage to the heat pump electronics.
F1255
FD1
FA1
FD1-SF2
UB2
UB1
UB3
Miniature circuit-breaker
The heat pump operating circuit and a large proportion
of its internal components are internally fused by a
miniature circuit breaker (FA1).
Temperature limiter
The temperature limiter (FD1) cuts the power to the
electric additional heat if the temperature exceeds 89°C
and is reset manually.
Resetting
The temperature limiter (FD1) is accessible behind the
front cover. Reset the temperature limiter by pressing
the button (FD1-SF2) using a small screwdriver.
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.
NIBE™ F1255Chapter 5 | Electrical connections20
5 Electrical connections