Gree GMV-N140U/A-T User manual

Owner's Manual
Air Conditioners
Models：
GMV-N140U/A-T
GMV-N280U/A-T
GMV-N560U/A-T
Gree Electric Appliances, Inc. of Zhuhai
Thank you for choosing Air Conditioners, please read this owner’s manual carefully before
operation and retain it for future reference.
GREE reserves the right to interpret this manual which will be subject to any change due to
product improvement without further notice.
GREE Electric Appliances, Inc. of Zhuhai reserves the final right to interpret this manual. If
you have lost the Owner’s Manual, please contact the local agent or visit www.gree.com or
sent email to [email protected] or electronic version.
INSTALLATION AND OPERATION MANUAL
FOR AHU-KIT UNIT

Preface
For correct installation and operation, please read all instructions carefully. Before reading the
instructions, please be aware of the following items:
(1) For the safe operation of this unit, please read and follow the instructions carefully.
(2) During operation, total capacity of indoor units should not exceed the total capacity of
outdoor units. Otherwise, poor effect of cooling or heating may result.
(3) Direct operators or maintainers should well keep this manual.
(4) If this unit fails to operate normally, please contact our service center as soon as possible
and provide the following information:
Content on the nameplate (model number, cooling capacity, production code, ex-factory
date).
Malfunction details (before and after the malfunction occurs).
(5) Each unit has been strictly tested and proved to be qualified before ex-factory. In order to
prevent units from being damaged or operating normally because of improper
disassembly, please do not disassemble the unit by yourself. If you need to disassemble
and check units, please contact our service center. We will send specialists to guide the
disassembly.
(6) Do only use this system in combination with a field supplied air handling unit. Do not
connect this system to other appliances.
(7) The outdoor unit and the air handling unit can both influence the overall performance of
the unit, please be sure to select appropriate outdoor unit, air handling unit and AHU-KIT
unit according to actually apply requirements.
(8) This equipment is not designed for year-round cooling applications with low indoor
humidity conditions, such as Electronic Data Processing rooms.
(9) All graphics in this manual is only for your reference. For sales or production reasons,
these graphics are subject to change by manufacturer without prior notice.
User Notice
This appliance can be used by children aged from 8 years and above and persons 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 understand the hazards involved. Children shall not play with the appliance.
Cleaning and user maintenance shall not be made by children without supervision.

Disposal
This marking indicates that this product should not be disposed
with other household wastes throughout the EU. To prevent
possible harm to the environment or human health from
uncontrolled waste disposal, recycle it responsibly to promote the
sustainable reuse of material resources. To return your used
device, please use the return and collection systems or contact
the retailer where the product was purchased. They can take this
product for environmental safe recycling.

Contents
1 Safety Precautions............................................................................................... 1
2 Product Introduction............................................................................................. 3
2.1 Names of Key Components..................................................................................................3
2.2 Overall System Connection Diagram.................................................................................. 3
3 Preparations for Installation ................................................................................. 4
3.1 Before Installation..................................................................................................................4
3.2 Standard Fittings.................................................................................................................... 4
3.3 Selecting the Air Handling Unit ............................................................................................5
3.4 Selecting the AHU-KIT Unit.................................................................................................. 5
3.5 Location for Installation......................................................................................................... 6
3.6 Requirements for Communication Wire.............................................................................. 7
3.7 Wiring Requirements............................................................................................................. 8
4 Installation Instructions......................................................................................... 9
4.1 Unit Dimensions and Maintenance Space......................................................................... 9
4.2 Piping Installation.................................................................................................................11
4.3 EXV Installation.................................................................................................................... 13
4.4 Installation of the Control Box............................................................................................ 14
4.5 Installation of the Thermistors............................................................................................ 16
4.6 Installation of the EXV Cable..............................................................................................18
4.7 Installation of Wired Controller........................................................................................... 18
5 Wire Connection .................................................................................................18
5.1 Connect Cables and Terminals of Wiring Board..............................................................19
5.2 Power Cord Connection......................................................................................................20
5.3 Connection of Communication Wire between Indoor Unit and Outdoor Unit (or Indoor
Unit)...................................................................................................................................................... 20
5.4 Connect Communication Wire of Wired Controller......................................................... 21
5.5 Illuminate for Connection of Wired Controller and Indoor Units (AHU-KIT) Network 21
6 Operation and Maintenance................................................................................22
6.1 Before Operation.................................................................................................................. 22
6.2 Test Operation ......................................................................................................................23
6.3 Routine Maintenance........................................................................................................... 23
6.4 Disposal Requirements....................................................................................................... 24
7 Table of Error Codes for Indoor Unit....................................................................24
8 Troubleshooting ..................................................................................................25

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
1
1 Safety Precautions
means items that must be forbidden! Otherwise, it may lead to personal injury or death or
serious damage.
means items that must be followed! Otherwise, it may lead to personal injury or property
loss.
Please install the unit
according to instructions in
this manual. Read this
manual carefully before
starting up or checking the
machine.
Installation should be performed by
dealer or qualified technicians. Do
not install the product by yourself.
Improper installation may result in
water leakage, electric shock or fire
hazard.
Make sure the local power
supply is in accordance with
units before installation, and
check the power supply
carefully.
When the installation is finished,
please check and make sure the
drain pipe, pipeline and electric
wire are all well connected in order
to avoid water leakage, refrigerant
leakage, electric shock or fire
hazard.
Please use specialized
accessories or parts to carry
out installation, or water
leakage, electric shock, fire
hazard may resulted.
R410A refrigerant can produce
poisonous gas once it meets fire,
so please ventilate the room
immediately if refrigerant leaks out
during installation.
Diameter of power cord must
be large enough. Damaged
power cord and connecting
wire must be replaced by
specialized electric cable.
After the power cord is connected,
please install the cover of electric
box to avoid danger.
Nitrogen must be charged
according to technical
requirements.
During Cooling mode, indoor
temperature should not be set too
low. Keep the difference between
indoor temp and outdoor temp
within 5°C.
For units with wired controller,
do not connect power supply
until the wired controller is
well installed. Otherwise, the
wired controller cannot be
used.
Volatile liquid like thinner or
gasoline will damage the
appearance of this product. (Please
use soft dry cloth and wet cloth with
mild detergent to clean the outer
case of air conditioner.)

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
2
Connect power supply 8
hours before operation. Do
not disconnect power if you
want to stop the unit in a short
period of time, e.g. in one
night. (This is for protecting
the compressor.)
If you use gas heater or
petroleum heater in the same room,
please open the door or window to
maintain good air circulation in
case the room may lack of oxygen.
Never start or stop this
product by inserting or
removing the power cord.
Do not turn off the air conditioner
until it runs for at least 5 minutes.
Otherwise, oil-return of the
compressor will be affected.
Children are not allowed to
operate this product.
Do not operate this product with
wet hands.
Please turn the unit off and
unplug your air conditioner
before cleaning. Otherwise, it
may cause electric shock or
personal injury.
Do not spray water on this product
or it will cause malfunction or
electric shock.
Do not expose this product
directly to water or place it in
a damp or corrosive
environment.
Do not repair this product by
yourself. Improper repair will cause
electric shock or fire hazard. Please
contact GREE service center and
have it repaired by professional
technicians.
This product must be properly
grounded through the
receptacle to avoid electric
shock. The grounding wire
shouldn't be connected with
gas pipe, water pipe, lightning
arrester or telephone line.
If abnormal condition occurs (e.g.
unpleasant smell), please turn off
the unit at once and disconnect
power supply. Then contact GREE
service center. If the air conditioner
continues to operate despite of
abnormal condition, the unit may be
damaged and it may cause electric
shock or fire hazard.)
Any personal injury or property loss caused by improper installation, improper debug,
unnecessary repair or not following the instructions of this manual should not be the responsibility
of Gree Electric Appliances, Inc. of Zhuhai.

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
3
2 Product Introduction
2.1 Names of Key Components
Fig.2.1
No.
①
②
Name
Control Box
Expansion valve kit Box
2.2 Overall System Connection Diagram
Fig.2.2

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
4
3 Preparations for Installation
3.1 Before Installation
Notes: Product graphics are only for reference. Please refer to actual products.
Unspecified measure unit is mm.
①This equipment is designed for R410A system, and the designed working pressure is 4.2
MPa or 42 bar.
②Precautions for R410A:
a).The refrigerant requires strict cautions for keeping the system clean, dry and tight.
—Clean and dry：Foreign materials (including mineral oils or moisture)should be prevented
from getting mixed into the system.
—Tight：Read this manual carefully and follow these procedures correctly.
b).Since R410A is a mixed refrigerant, the required additional refrigerant must be charged
in its liquid state. ( If the refrigerant is in state of gas, its composition changes and the
system will not work properly).
c).The connected air handling units must have heat exchangers designed exclusively for
R410A．
③Never use this appliance under inflammable and explosive gas.
④For the following items, take special care during construction and check after installation
is finished:
Tick √when checked
□Are the thermistors fixed firmly?
Thermistor may come loose.
□Is the capacity code setted correctly?
The performance of system may not achieve it’s requirement.
□Is the control box fixed firmly?
The unit may drop, vibrate or make noise.
□Do electrical connections comply with specifications?
The unit may malfunction or components may burn out.
□Are wiring and piping correct?
The unit may malfunction or components may burn out.
□Is the unit safely grounded?
Dangerous at electric leakage.
3.2 Standard Fittings
Please use the supplied standard fittings listed below as instructed.
No.
Name
Appearance
Quantity
1
Magnetic ring
1
2
Swell screw
4

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
5
3
Self-tapping screw
4
4
Operating Instruction Manual
1
5
Wired controller
1
3.3 Selecting the Air Handling Unit
Select the air handling unit according to the technical data and limitations mentioned in the
following table. Lifetime of the outdoor unit, operation range or operation reliability may be
influenced if you neglect these limitations.
Model
capacity
（kW）
Allowable internal volume
of heat exchanger (dm3)
Allowable capacity of
heat exchanger (kW)
Suggested air
volume (m3/h)
Minimum
Maximum
Minimum
Maximum
GMV-N140U/A-T
9.0
2.09
2.64
7.9
9.9
1500~1850
11.2
2.65
3.3
10
12.3
1850~2100
14.0
3.31
4.12
12.4
15.4
2100~2400
GMV-N280U/A-T
22.4
4.63
6.60
17.7
24.6
3700~4200
28.0
6.61
8.25
24.7
30.8
4200~4800
GMV-N560U/A-T
45.0
10
11.8
42.5
47.5
7400~8000
50.4
11.9
13.7
47.6
53.2
8000~5600
56.0
13.8
15.6
53.3
58.7
8600~9200
Notes:
a) The capacity of heat exchanger is obtained at these test conditions: evaporation temperature at air outlet of
heat exchanger is 6℃, overheating degree of heat exchanger is 5℃and the air return temperature is 27℃
DB/19℃WB.
b) The heat exchanger of air handling unit is designed for R410A, and it’s working pressure is 4.2MPa.
c) Quantity of rows of heat exchanger: no more than 4 rows.
d) The diameter of copper pipe of heat exchanger is no more than 12.7mm. 9.52mm is recommended.
Notes: The air handling unit can be connected as a standard indoor unit to the outdoor unit.
The limitations of connection are determined by the outdoor unit.
3.4 Selecting the AHU-KIT Unit
The corresponding AHU-KIT unit needs to be selected for your air handling unit. Select the
AHU-KIT unit according to the above limitations.
Capacity ranges of different AHU-KIT unit are as follows:
Model
Acquiescent capacity (kW)
Adjustable capacity (kW)
GMV-N140U/A-T
14.0
9.0/11.2/14.0
GMV-N280U/A-T
28.0
22.4/28
GMV-N560U/A-T
56.0
45/50.4/56
Different capacities of same model of AHU-KIT unit are achieved through dialing capacity
code of mainboard (shown as "S1").Capacity code setting is shown as follows:

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
6
S1
Capacity
(kW)
1
2
3
4
5
0
0
1
1
0
9.0
0
1
1
1
0
11.2
0
0
0
0
1
14.0
1
1
0
0
1
22.4
1
0
1
0
1
28.0
1
0
0
1
1
45.0
0
1
0
1
1
50.4
1
1
0
1
1
56
Please ensure dialing the code switch properly in place instead of middle position. Setting the
switch to "ON" stands for "0", otherwise stands for "1".
(Notes: The black part is the deflector rod.) The figure shows that the addresses of ”1,2,3,4,5”
are ”0,0,1,0,0”.
Notes:
①The selected air handling unit must be designed for R410A.
②Extraneous substances (including mineral oils or moisture) must be prevented from
getting mixed into the system.
3.5 Location for Installation
Select an installation site where the following conditions are fulfilled and that meets your
customer’s approval.
(1) The EXV box can be installed inside and outside. The control box should be installed
inside.
(2) Do not install the EXV box in or on the outdoor unit.
(3) Do not put the option boxes in direct sunlight. Direct sunlight will increase the
temperature inside the option boxes and may reduce its lifetime and influence its
operation.
(4) Choose a flat and strong mounting surface.
(5) Make sure there is enough free space in front and in the side of the AHU-KIT unit for
future maintenance.
(6) The installation site should be far away from heat source, inflammable gas and smoke.
(7) Keep the air handling unit, power supply wiring and transmission wiring at least 1 m away
from televisions and radios. This is to prevent image interference and noise in those
electrical appliances. (Noise may be generated depending on the conditions under which
the electric wave is generated, even if 1 m is kept.)
(8) Make sure the electronic expansion valve is installed in an upright position.

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
7
Notes!
①Do not install or operate the unit in rooms mentioned below:
a). Where mineral oil, like cutting oil is present.
b). Where the air contains high levels of salt such as air near the ocean.
c). Where sulphurous gas is present such as that in areas of hot spring.
d). In vehicles or vessels.
e). Where voltage fluctuates a lot such as that in factories.
f). Where high concentration of vapor or spray are present.
g). Where machines generating electromagnetic waves are present.
h). Where acidic or alkaline vapor is present.
②Installing this unit must comply with the relevant local and national codes.
③Connecting the power after all installation works are done.
3.6 Requirements for Communication Wire
Notes:
If the unit is installed in the place with strong electromagnetic interference, shielded wire
must be applied on the communication wire between indoor unit (AHU-KIT) and wired
controller. Twisted pair wire with shielding function must be applied on the communication
wire between indoor unit and indoor unit (outdoor unit).
3.6.1 Selecting communication wire for AHU-KIT and wired controller
Fig.3.6.1
Wire Type
Total Length of
Communication wire L(m)
Wire Gauge (mm2)
Remark
Light/Common PVC
Jacket Soft Wire
L ≤ 250
2×0.75 ～2×1.25
The total length of
communication wire should
not exceed 250m.
Light shield/Common
PVC Jacket Soft Wire
L ≤ 250
2×0.75 ～2×1.25
The shield cable is required
when the unit is installed in
the environment of strong
magnetic or interference.

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
8
3.6.2 Select Communication wire for AHU-KIT and Outdoor Unit
Fig.3.6.2
Wire Type
Total Length of Communication
wire L(m)
Wire Gauge
(mm2)
Remark
Light/Common PVC Jacket
Soft Wire
L ≤ 1000
≥ 2×0.75
If wire gauge is 2X1 mm2,
then it’s OK to increase the
length of communication
wire. But total length should
not exceed 1500m.
Light shield/Common PVC
Jacket Soft Wire
L ≤ 1000
≥ 2×0.75
The shield cable is required
when the unit is installed in
the environment of strong
magnetic or interference.
3.7 Wiring Requirements
Power Cord Size and Air Switch Capacity:
Model
Power Cord Size
Air Switch
Capacity(A)
Ground Wire
Power Cord
Minimum Sectional
Area(mm2)
Minimum Sectional
Area(mm2)
GMV-N140U/A-T
220~240V/1ph/50Hz &
208~230V/1ph/60Hz
6
1.0
1.0
GMV-N280U/A-T
6
1.0
1.0
GMV-N560U/A-T
6
1.0
1.0
Notes:
①Use copper wire only as unit’s power cord. Operating temperature should be within its
rated value.
②Above selection requirements: Power cord size is based on BV single-core wire (2~4pc)
at 40°Cambient temperature when laying across plastic pipe. Air switch is D type and
used at 40°C. If actual installation condition varies, please lower the capacity
appropriately according to the specifications of power cord and air switch provided by
manufacturer.
③Install cut-off device near the unit. The minimum distance between each stage of cut-off
device should be 3 mm (The same for both indoor unit and outdoor unit).

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
9
4 Installation Instructions
4.1 Unit Dimensions and Maintenance Space
(1) Size of control box for GMV-N140U/A-T、GMV-N280U/A-T and GMV-N560U/A-T (Unit: mm):
Fig.4.1.1
Maintenance space of control space (Unit: mm):
Fig.4.1.2

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
10
(2) Size of EXV box for GMV-N140U/A-T and GMV-N280U/A-T(Unit: mm):
Fig.4.1.3
Size of EXV box for GMV-N560U/A-T (Unit: mm):
Fig.4.1.4
Maintenance space of EXV box (Unit: mm):
Fig.4.1.5

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
11
4.2 Piping Installation
4.2.1 Diagram of Piping Connection
Fig.4.2
(1) Air handling unit
(2) Connection pipe from expansion valve kit to air handling unit
(3) Valve kit
(4) Liquid pipe
(5) Gas pipe
Notes:
A: When the air handling unit is installed at the top of the EXV box, vertical distance between
the bottom of the air handling unit to the EXV box is no more than 2 m; if the air handling unit is
installed under the EXV box, vertical distance between the bottom of the air handling unit to the
EXV box is no more than 2 m.
L: The length of liquid pipe between the air handling unit to EXV box is no more than 2 m.
L is to be considered as a part of the total maximum piping length. See installation manual of
the outdoor unit for piping installation.
4.2.2 Piping Connections
Make sure to install gas and liquid pipe diameters in function of the air handling unit capacity
class.
Model
Capacity(kW)
Gas pipe(mm)
Connection pipe
Liquid pipe(mm)
GMV-N140U/A-T
9.0
Φ15.9
Φ9.52
11.2
Φ15.9
Φ9.52
14.0
Φ15.9
Φ9.52
GMV-N280U/A-T
22.4
Φ19.05
Φ9.52
28.0
Φ22.2
Φ9.52
GMV-N560U/A-T
45.0
Φ28.6
Φ12.7(*)
50.4
Φ28.6
Φ15.9
56.0
Φ28.6
Φ15.9
(*)Note:
The internal diameter of both inlet tube and outlet tube of EXV box for GMV-N560U/A-T is
Φ16.3mm. It needs engineering treatment on the scene if you want to connect liquid pipe of
Φ12.7mm( expanding the copper tube of Φ12.7mm or using a connection copper tube) in order to

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
12
satisfy the clearance requirement of brazing(the clearance requirement is 0.1~0.2mm normally).
4.2.3 Selection of Piping
(1) Ensure the inside of the pipes is clean and no foreign materials.
(2) Pipe specifications:
R410A System
Pipe Φ（mm/inch）
Thickness(mm)
Temper grade of piping material
Φ6.35（1/4）
≥0.8
O
Φ9.52（3/8）
≥0.8
O
Φ12.70（1/2）
≥0.8
0
Φ15.9（5/8）
≥1.0
0
Φ19.05（3/4）
≥1.0
0
Φ22.2（7/8）
≥1.2
1/2H
Φ25.40（1/1）
≥1.2
1/2H
Φ28.6（9/8）
≥1.2
1/2H
Φ31.8（5/4）
≥1.3
1/2H
Φ34.90（11/8）
≥1.3
1/2H
Φ38.10（12/8）
≥1.5
1/2H
Φ41.30（13/8）
≥1.5
1/2H
Φ44.5（7/4）
≥1.5
1/2H
Φ51.4（7/4）
≥1.5
1/2H
Φ54.1（17/8）
≥1.5
1/2H
4.2.4 Cautions for Brazing
(1) Make sure there is nitrogen protection during welding.
Brazing without carrying out nitrogen replacement or releasing nitrogen into the piping will
create large quantities of oxidized film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing normal operation.
(2) When brazing while inserting nitrogen into the piping, nitrogen must be set to 0.02 MPa
with a pressure-reducing valve (=just enough so that it can be felt on the skin).
Fig.4.2.4
a) Refrigerant piping
b) Part to be brazed
c) Taping
d) Hands valve
e) Pressure-reducing valve
f) Nitrogen
(3) For details, see manual of the outdoor unit.
Notes:

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
13
All field piping must be provided by a licensed refrigeration technician and must comply with
the relevant local and national codes.
①For refrigerant piping of outdoor unit, refer to the installation manual supplied with the
outdoor unit.
②The maximum allowed piping length depends on the connected outdoor model.
4.3 EXV Installation
4.3.1 Mechanical Installation
(1) Remove the EXV box cover by unscrewing screws.
(2) Drill 4 holes on correct position (measurements as indicated in figure below) and fix the
valve kit box securely with 4 screws through the provided holes Ø12 mm.
Notes:
①Make sure that the EXV box is installed upwards.
②Make sure there is enough free space in front and in the side of the box for future
maintenance.
4.3.2 Brazing Work
(1) Prepare the inlet/outlet field piping just in front of the connection (do not braze yet).
Fig.4.3.2
A Inlet coming from the outdoor unit
B Outlet to air handling unit
C Wire clamp
(2) Remove the wire clamp (C) by unscrewing 6xM4.2.
(3) Braze the field piping.
Notes:
①Make sure to cool the filters and valve body with a wet cloth and make sure the body
temperature does not exceed 120°C during brazing.
②Make sure that the other parts such as electrical box, tie wraps and wires are
protected from direct brazing flames during brazing.

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
14
(4) Secure the wire clamp (C) in place again (6xM4.2).
(5) Make sure that field pipes are fully insulated. Make sure that there is no gap between
both ends in order to avoid condensation dripping (finish the connection with tape
eventually).
4.4 Installation of the Control Box
Fig.4.4
4.4.1 Mechanical Installation
（1）Fix the control box with its hanger brackets to the mounting surface.
（2）Open the lid of the control box.
（3）For electrical wiring: refer to the following contents.
（4）Install the screw nuts.
（5）Close the unnecessary openings.
（6）Close the lid securely after installation to ensure that the control box is watertight.
4.4.2 Wire connection Inside the Control Box
Notes:
①Pull the wires inside through the screw nut and close the nut firmly in order to ensure a
good pull relieve and water protection.
②The cables require an additional pull relief. Fixing the cable with the wire clamp.
Fig.4.4.2.1

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
15
Precautions:
(1) Thermistor cable and remote controller wire should be kept away from power cable in a
distance of at least 50mm. Violating this rule may generate electric noise and lead to
malfunctions.
(2) Use wires as specified and connect them tightly with wiring terminals. Keep the wires in
order and do not obstruct other devices. Insecure connection may result in overheating
or even cause electric shock or fire hazard.
Wiring connection:
Fig.4.2.2.2
Connecting cables according to the following instructions, as figure shown above.
L......................... Live
N........................ Neutral
..................... Protective earth (screw)
H........................High gear of fan
M........................Middle gear of fan
L........................ Low gear of fan
1/2........................ Lines of fault signal from external feedback
D1/D2........................Communication wires
H1/H2........................Wired controller
Notes:
①The H, M, L of fan gear lines and the 1, 2 of Lines of fault signal from external feedback
are shorted by the factory default.
②Neutral line of fan connects to the N.
It can be connected to any of them (H, M, L) when there is only one gear.
Disconnect the short cable between H and M when there are two gears, then connect
the high gear cable to H, and connect low gear cable to either M or L.
When there are three gears, disconnect the short cables between H and M, M and L,
then connect the high gear cable, middle gear cable and low gear cable to H,M,L for
each.
③The lines of fault signal from external feedback are connected to the 1, 2.The line is a dry
contact and closed normally. If the line is closed, it represents no fault and the system
operates normally; if the line is disconnected, it represents malfunction and the system
will stop.
④Disconnect the short cable between 1 and 2 when there is fault signal, and connect the
signal cable to 1 and 2.

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
16
⑤Pull the wires inside through the screw nut and close the nut firmly in order to ensure a
good pull relieve and water protection.
⑥The cables require an additional pull relief. Fixing the cable with the wire clamp.
4.5 Installation of the Thermistors
4.5.1 Refrigerant Thermistors
Location of the thermistor:
A correct installation of the thermistors is required to ensure a good operation:
(1) Liquid(RT4)
Install the thermistor behind the distributor on the coldest pass of the heat exchanger (contact
your heat exchanger dealer).
(2) Gas (RT2)
Install the thermistor at the outlet of the heat exchanger as close as possible to the heat
exchanger.
Fig.4.5.1.1
①Liquid RT4
②Gas RT2
Installation of the thermistor cable
(1) The length of thermistor wire is 10 m.
(2) Put the thermistor cable in an individual protective tube.
(3) Apply stress release in the temperature sensor wire to prevent the temperature sensor
wire from getting loose due to stress. Stress or looseness of temperature sensor wire will
lead to poor contact and inaccuracy of temperature measuring.
Fixation of the thermistor
Notes:
①Put the thermistor wire slightly down to avoid water accumulation on top of the thermistor.
Fig.4.5.1.2

OPERATING INSTALLATION MANUAL FOR AHU-KIT UNIT
17
②Keep the thermistor and air handling unit in good contact. Put the top of the thermistor on
the air handling unit, because the top of thermistor is the most sensitive part. Please
fixing the thermistor on the horizontal plane of copper tube (within ±30°), and make them
close together.
Fig.4.5.1.3
(1) Fix the thermistor with insulating aluminum tape in order to ensure good heat
transference.
Fig.4.5.1.4
(2) Cover the thermistor with rubber belt to prevent looseness of temperature sensor.
’
Fig.4.5.1.5
(3) Use two wire ties to bind the thermistor securely.
Fig.4.5.1.6
(4) Wrap the thermistor with insulating trip.
Fig.4.5.1.7