Nortek GKU18USV4DH Service manual

Nortek Global HVAC, LLC
Installation Instructions / Owner's Manual
Heat Pump
ƽPlease read this owner’s manual carefully before operation and retain it for future reference
ƽSpecifications & illustrations subject to change without notice or incurring obligations
Indoor Unit
Outdoor Unit
GKU18(5.3)USV4DH GXH18(5.3)USV4DH
GKU24(7.0)USV4DH
GKU30(8.8)USV4DH
GXH24(7.0)USV4DH
GXH30(8.8)USV4DH
GKU36(10.6)USV4DH GXH36(10.6)USV4DH
GKU42(12.3)USV4DH
GKU48(14.1)USV4DH
GXH42(12.3)USV4DH
GXH48(14.1)USV4DH
DC Inverter U-Match Series
Cassette Type Unit

Contents

1 Safety Precautions................................................................................ 1
2 Outline of the Unit and Main Parts........................................................ 3
3 Preparative for Installation .................................................................... 4
3.1 Standard Accessory Parts ........................................................................... 4
3.2 Selection of the Installation Location ........................................................... 5
3.3 Connection Pipe Requirement..................................................................... 7
3.4 Electrical Requirement................................................................................. 8
4 Installation of the Unit ...........................................................................9
4.1 Installation of the Indoor Unit ....................................................................... 9
4.2 Installation of the Outdoor Unit .................................................................. 13
4.3 Installation of the Connection Pipe ............................................................ 14
4.4 Vacuum and Gas Leakage Inspection....................................................... 18
4.5 Installation of the Drain Hose..................................................................... 20
4.6 The Panel Installation ................................................................................ 24
4.7 Electrical Wiring......................................................................................... 26
5 Installation of Controllers ....................................................................33
6 Test Running ......................................................................................33
6.1 Trial Operation and Testing ....................................................................... 33
6.2 Working Temperature Range ....................................................................35
7 Troubleshooting and Maintenance ..................................................... 36
7.1 Troubleshooting......................................................................................... 36
7.2 Routine Maintenance................................................................................. 36

DC Inverter U-match Series Cassette Type Unit
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1 Safety Precautions
WARNING NOTICE: Failure to comply with warning notice could result in
property damage, serious personal injury or death.
CAUTION NOTICE: Failure to comply with caution notice could result in property
damage or personal injury.
NOTICE: Failure to comply with notice could result in property damage.
(1).
Instructions for installation and use of this product are provided by the manufacturer.
(2).
Installation must be performed by qualified personnel only.
(3).
Improper installation may cause water leakage, electrical shock, or fire.
(4).
Install the air conditioner according to the i
nstructions given in this manual. Incomplete
installation may cause water leakage, electrical shock, or fire.
(5).
Be sure to use the supplied or specified installation parts. Use of other parts may cause the unit
to come to lose, water leakage, electrical shock, or fire.
(6).
Install the air conditioner on a solid base that can support the weight of the unit. An inadequate
base or incomplete installation may cause injury in the event the unit falls off the base.
(7).
Electrical work should be carried out in accorda
nce with the installation manual and the
national electrical wiring rules or code of practice. Insufficient capacity or incomplete electrical
work may cause electrical shock or fire.
(8).
Be sure to use a dedicated power circuit. Never use a power supply sha
red by another
appliance.
(9).
For wiring, use a single length of cable with no connections
. Do not use an extension cord. Do
not put other loads on the power supply, use a dedicated power circuit. (Failure to do so may
cause terminal overheating, electric shock or fire.)
(10).
Use the specified types of wires for electrical connections between the indoor and outdoor
units. Firmly clamp the interconnecting wires so their terminals receive no external stresses.
Improper connections or clamping may cause terminal overheating or fire.
(11).
After connecting interconnecting and supply wiring be sure to shape the cables so that they do
not put undue force on the electrical covers or panels. Install covers over the wires.
Improper
cover installation may cause terminal overheating, electrical shock, or fire.
(12).
If any refrigerant has leaked out during the installation work, ventilate the room. (The refrigerant
produces a toxic gas if exposed to flames.)
(13).
After all installation is complete, check to make sure that no refrige
rant is leaking out. (The
refrigerant produces a toxic gas if exposed to flames.)
(14).
When installing the system, be sure to keep the refrigerant circuit free from substances other
than the specified refrigerant (R410A), such as air. (Any presence of air or
other foreign
substance in the refrigerant circuit causes an abnormal pressure rise or rupture, resulting in
injury.)

DC Inverter U-match Series Cassette Type Unit
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(15).
During pump-
down, stop the compressor before removing the refrigerant piping. If the
compressor is still running and the stop valve is open during pump-
down, air will be sucked in
when the refrigerant piping is removed, causing abnormal pressure in the freezer cycle which
will lead to breakage and even injury.
(16).
During installation, attach the refrigerant piping securely before running the
compressor. If the
compressor is not attached and the stop valve is open during pump-
down, air will be sucked in
when the compressor is run, causing abnormal pressure in the freezer cycle which will lead to
breakage and even injury.
(17).
Be sure to ground equipment. Do not ground
the unit to a utility pipe, arrester, or telephone
conduit. Incomplete grounding
may cause electrical shock, or fire. A high surge current from
lightning or other sources may cause damage to the air conditioner.
(18).
Be sure to install ground fault interrupter. Failure to install a ground fault interrupter
r may result
in electric shocks, or fire.
(19).
This appliance is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge,
(20).
Children should be supervised to ensure that they do not play with the appliance.
(21).
If the supply cord is damaged, it must be replaced with and appropriate size cord.
(1).
Do not install the air conditioner in a place where there
is danger of exposure to inflammable
gas leakage. If the gas leaks and builds up around the unit, it may catch fire.
(2).
Establish drain piping according to the instructions of this manual. Inadequate piping may
cause flooding.
(3).
Tighten the flare nut accord
ing to the specified method such as with a torque wrench. If the
flare nut is tightened too much, the flare nut may crack and cause refrigerant leakage.

DC Inverter U-match Series Cassette Type Unit
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2 Outline of the Unit and Main Parts
Fig. 2.1
The connection pipe, drain pipe, power cord, and duct for this unit should be prepared by a
qualified technician.

DC Inverter U-match Series Cassette Type Unit
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3 Preparation for Installation
3.1 Standard Accessory Parts
The standard accessory parts listed below are furnished and should be used as
required.
Table 3.1
Indoor Unit Accessories
No.
Name Appearance
Q'ty
Usage
1
Drain Hose 1
To connect with the hard
PVC drain pipe
2
Nut with Washer
4
To fix the
hook on the
cabinet of the unit
(for
24k~48k units)
3
Washer
10
To be used together with the
hanger bolt for installing the
unit (for 24k~48k units)
4
installation
template
1
U
sed for ceiling drilling
5
Gasket mounting
board
4
Used to prevent gasket from
falling off
6
Wireless Controller
+Battery
1+2
To control the indoor unit
7
sealing plaster
1
8
Fastener 4
To fasten the sponge
9
Insulation 1
To insulate the gas pipe
10
Insulation 1
To insulate the liquid pipe
11
Sponge 3
To insulate the drain pipe
12
Nut 1
To connect gas pipe
13
Nut 1
To connect liquid pipe
14
Enswathement
2

DC Inverter U-match Series Cassette Type Unit
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Table 3.2
Outdoor Unit Accessories
No.
Name
Appearance
Q'ty
Usage
1
Drain Plug
1
or 3
To plug the unused drain hole
2
Drainage Connecter
or
1
To connect with the hard PVC
drain pipe
3.2 Selection of the Installation Location
ķ. Check the support structure to verify that it has sufficient load-
carrying capacity to support the
weight of the unit, and it can be securely mounted.
ĸ
. Do not install where there is a danger of combustible gas leakage.
Ĺ
. Do not install the unit near heat source, steam, or flammable gas.
ĺ
. Children should be kept away from unit.
Decide the installation location with the customer as follows:
3.2.1 Indoor Unit
Select an installation site where the following conditions are fulfilled and that
meets your customer's approval.
(1). No obstruction should block the air inlet or outlet vents.
(2). Make sure that the installation meets the requirement of the schematic
diagram of installation spaces.
(3). Check the support structure to verify that it has sufficient load carrying
capacity to support 4 times the weight of the indoor unit. Mount the unit
securely to reduce vibration noise.
(4). Unit should be mounted level.
(5). Select a location with easy access to outdoor unit and convenient
condensate drain connection.
(6). Be sure to leave sufficient space around the unit for service and
maintenance. Unit should be mounted a minimum of 1.8M (6 feet) above
the floor.
(7). When installing the suspension bolt, check if the structure can withstand 4
times of the weight of the unit. If not, reinforce it before installation.

DC Inverter U-match Series Cassette Type Unit
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Note: If the unit is mounted in a kitchen or dining room, there may be build-up of greasy dirt on
the fan, heat exchanger and water pump. This will reduce the effectiveness of the system and
may cause it to malfunction.
Fig. 3.1
Table 3.3
3.2.2 Outdoor Unit
ķ
. Install the unit where it will not be tilted by more than 5°.
ĸ
. The outdoor unit should be securely mounted to withstand high wind.
If possible, do not install the unit where it will be exposed to direct sunlight. (If
necessary, install a blind that does not interfere with the air flow.)
(1). Install the outdoor unit in a place where it will be free from dirt or rain as
much as possible.
(2). Install the outdoor unit where it is convenient to connect with the indoor
unit.
(3). Install the outdoor unit where the condensate water can be drained out
Models H
mm (inch)
GKU18(5.3)USV4DH
255(10)
GKU24(7.0)USV4DH
260(10-1/4)
GKU30(8.8)USV4DH
340(13-3/8)
GKU36(10.6)USV4DH
340(13-3/8)
GKU42(12.3)USV4DH
340(13-3/8)
GKU48(14.1)USV4DH
320(12-5/8)

DC Inverter U-match Series Cassette Type Unit
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freely during heating operation.
(4). Do not place animals and plants in the path of the warm air.
(5). Check the support structure to verify that it has sufficient load-carrying
capacity to support the weight of the unit. Mount the unit securely to reduce
vibration noise.
(6). Provide the space shown in Fig. 3.2, so that the air flow is not blocked. Also
for efficient operation, leave three of four directions of peripheral
constructions open.
Fig. 3.2
3.3 Connection Pipe Requirement
The maximum length of the connection pipe is listed in the Tabl
e below..
Table 3.4
Item
Model
Size of Fitting Pipe
mm (inch)
Max. Pipe
Length
m (feet)
Max. Height
Difference
between Indoor
Unit and
Outdoor Unit
m (feet)
Drainage
pipe(Outer
Diameter × wall
thickness)
mm (inch)
Liquid
Gas
GKU18(5.3)USV4DH
GXH18(5.3)USV4DH
6(1/4)
12.7(1/2)
50(164)
15(49-1/4
)
Φ25×1.5
(Φ1 X 1/16)
GKU24(7.0)USV4DH
GXH24(7.0)USV4DH
9.5(3/8)
16(5/8)
50(164)
15(49-1/4
)
Φ25×1.5
(Φ1 X 1/16)
GKU30(8.8)USV4DH
GXH30(8.8)USV4DH
9.5(3/8)
16(5/8)
50(164)
15(49-1/4
)
Φ25×1.5
(Φ1X 1/16
)
GKU36(10.6)USV4DH
GXH36(10.6)USV4DH
9.5(3/8)
16(5/8)
50(164)
15(49-1/4
)
Φ25×1.5
(Φ1 X 1/16
)
GKU42(12.3)USV4DH
GXH42(12.3)USV4DH
9.5(3/8)
16(5/8)
50(164)
15(49-1/4
)
Φ25×1.5
(Φ1 X 1/16)

DC Inverter U-match Series Cassette Type Unit
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GKU48(14.1)USV4DH
GXH48(14.1)USV4DH
9.5(3/8)
16(5/8)
70(
230)
15(49-1/4
)
Φ25×1.5
(Φ1 X 1/16)
Notes:
ķ. The connection pipe should be insulated with proper water-proof material.
ĸ. The pipe wall thickness shall be 0.5~1.0mm (0.02~0.04 inch) and the pipe
wall shall be able to withstand the pressure of 6.0MPa (870psig). The
shorter the connecting pipe, the better the cooling and heating effect.
3.4 Electrical Requirement
Electric Wire Size and Fuse Capacity.
Table 3.5
Indoor Units
Power Supply
Fuse
Capacity
Minimum
Circuit
Ampacity
Maximum
Overcurrent
Protection
V/Ph/Hz
A
A
A
GKU18(5.3)USV4DH
208/230V ~ 60Hz
5
1
15
GKU24(7.0)USV4DH
208/230V ~ 60Hz
5
1
15
GKU30(8.8)USV4DH
208/230V ~ 60Hz
5
1.5
15
GKU36(10.6)USV4DH
208/230V ~ 60Hz
5
1.5
15
GKU42(12.3)USV4DH
208/230V ~ 60Hz
5
1.5
15
GKU48(14.1)USV4DH
208/230V ~ 60Hz
5
2
15
Table 3.6
Outdoor Units
Power Supply
Fuse
Capacity
Minimum
Circuit
Ampacity
Maximum
Overcurrent
Protection
V/Ph/Hz
A
A
A
GXH18(5.3)USV4DH
208/230V ~ 60Hz
5
17
25
GXH24(7.0)USV4DH
208/230V ~ 60Hz
5
24
40
GXH30(8.8)USV4DH
208/230V ~ 60Hz
5
24
40
GXH36(10.6)USV4DH
208/230V ~ 60Hz
5
29
45
GXH42(12.3)USV4DH
208/230V ~ 60Hz
5
31
50
GXH48(14.1)USV4DH
208/230V ~ 60Hz
5
45
70
Notes:
ķ. The fuse is located on the main board.
ĸ. Install the disconnect device with a contact gap of at least 3mm (1/8inch) in
all poles nearby the units (Both indoor unit and outdoor unit).The appliance
must be positioned so that the plug is accessible.

DC Inverter U-match Series Cassette Type Unit
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Ĺ. Use 2 pieces of power cord of 0.75mm2(AWG18) as the communication
lines between indoor and outdoor unit, with their longest lengths of 50m
(164feet). Please select the appropriate line length per the actual
installation conditions. The communication lines can not be twisted together.
For the unit (≤30k), it’s recommended to use 8m (26feet) long
communication line.
ĺ. Take 2 pieces of power cord of 0.75mm2(AWG18) as the communication
lines between the wired controller and the indoor unit, with their longest
lengths of 30m (98- ½ feet). Please select the appropriate line length as per
the actual installation conditions. The communication lines can not be
twisted together. It’s recommended to use 8m (26feet) long communication
line.
Ļ. The wire size of the communication line should be no less than 0.75mm2
(AWG18). It’s recommended to take 0.75mm2(AWG18) power cords as the
communication line.
4 Installation of the Unit
4.1 Installation of the Indoor Unit
4.1.1 Indoor unit dimension
For the units: GKU18(5.3)USV4DH

DC Inverter U-match Series Cassette Type Unit
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Table 4.1
Unit: mm (inch)
Item
Model
A B
C
D
E
F
G
H
I
J
GKU18(5.3)
USV4DH
670
(26
-
3/8)
595
(23
-7
/16)
592
(23
-
1/4)
575
(22
-
5/8)
145
(5
-
3/4)
240
(9
-
1/2)
665
(26
-
1/8)
236
(9
-
1/4)
575
(22
-
5/8)
505
(19
-
7/8)
For the units: GKU24(7.0)USV4DH ~ GKU42(12.3)USV4DH
Table 4.2
Unit: mm (inch)
Item
Model
A B C D
E
F G
H
I
GKU24(7.0)USV4DH
950
(37-3/8)
840
(33-1/8)
780
(30-3/4)
680
(26-3/4)
160
(6-1/4)
240
(9-1/2)
91
5
(36)
215
(8-1/2)
993
(39-1/8)
GKU30(8.8)USV4DH
950
(37-3/8)
840
(33-1/8)
780
(30-3/4)
680
(26-3/4)
160
(6-1/4)
320
(12-5/8)
91
5
(36)
215
(8-1/2)
993
(39-1/8)
GKU36(10.6)USV4DH
950
(37-3/8)
840
(33-1/8)
780
(30-3/4)
680
(26-3/4)
160
(6-1/4)
320
(12-5/8)
91
5
(36)
215
(8-1/2)
993
(39-1/8)
GKU42(12.3)USV4DH
950
(37-3/8)
840
(33-1/8)
780
(30-3/4)
680
(26-3/4)
160
(6-1/4)
320
(12-5/8)
91
5
(36)
215
(8-1/2)
993
(39-1/8)

DC Inverter U-match Series Cassette Type Unit
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For the units: GKU48(14.1)USV4DH
Fig. 4.1
Table 4.3
Unit: mm (inch)
Item
Model
A B C D E F
GKU48(14.1)
USV4DH
1040(41)
910(35
-
7/8)
842(33
-
1/8)
788(31)
170(6
-
3/4)
290(11
-
3/8)
4.1.2 Installing the Main Body Unit
Fig. 4.2
(1). Install the hoisting stand on the hoisting screw by using nuts and gaskets at
both the upper and lower sides of the hoisting stand. To prevent the gasket
from breaking off, a gasket anchor board should be used.
(2). Install the paper template on the unit, and fix the drain pipe at the outlet

DC Inverter U-match Series Cassette Type Unit
12
vent.
(3). Adjust the unit to the best position.
(4). Check if the unit is installed level in four directions. If not, the water pump
and the float switch will malfunction and may cause leakage.
(5). Remove the gasket anchor board and tighten the nut.
(6). Remove the paper template.
4.1.3 Installing the Suspension Bolts
(1). Using the installation template, drill holes for bolts (four holes) (Fig. 4.3).
(2). Install the bolts to the ceiling at a place strong enough to hang the unit.
Mark the bolt positions from the installation template. With a concrete drill,
drill four 12.7mm (1/2inch) diameter holes (Fig. 4.4).
(3). Insert the anchor bolts into the drilled holes, and drive the pins completely
into the anchor bolts with a hammer (Fig. 4.5).
Fig.4.3 Fig.4.4 Fig.4.5
4.1.4 Leveling
The water level test must be done after installing the indoor unit to make the unit
is level, as shown below.
Fig. 4.6

DC Inverter U-match Series Cassette Type Unit
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4.2 Installation of the Outdoor Unit
ķ. Install the unit where it will not be tilted by more than 5°.
ĸ. During installation, if the outdoor unit has to be exposed to strong wind, it must be fixed secur
ely.
4.2.1 Outdoor unit dimension
Fig. 4.7
Table 4.4 Unit: mm (inch)
Item
Model
A B C D E
GXH18(5.3)USV4DH
955(37-5/8)
395(15-1/2)
700(27-1/2)
560(22)
360(14-1/8)
GXH24(7.0)USV4DH
980(38
-
5/8)
42
5(16-
3/4)
790(31
-
1/8)
610(24
)
395(15
-
1/2)
GXH30(8.8)USV4DH
GXH36(10.6)USV4DH
1105(43-5/8)
440(17-3/8)
1100(43-1/4)
630(24-7/8)
400(15-3/4)
GXH42(12.3)USV4DH
9
60(37-
3/4)
41
0(16-
1/4)
13
50(53-
1/8)
57
0(22-
1/2)
37
5(14-
3/4)
GXH48(14.1)USV4DH
4.2.2 Condensate Drainage of the Outdoor Unit (for the heat
pump unit only) (Fig. 4.8)
(1). It is required to install a drain pipe for the outdoor unit to drain condensate
water during heating operation (only for the heat pump unit).
(2). All holes, with the exception of the drain pipe hole, should be plugged so as
to avoid water leakage (only for the heat pump unit).
(3). Installation Method: Insert the pipe joint into the φ25mm (1inch) hole

DC Inverter U-match Series Cassette Type Unit
14
located at the base plate of the unit and then connect the drain pipe to the
pipe joint.
Fig. 4.8
4.3 Installation of the Connection Pipe
4.3.1 Flare Proces
(1). Cut the connection pipe with pipe cutter and remove the burrs.
(2). Hold the pipe downward to prevent cuttings from entering the pipe.
(3). Remove the flare nut from the stop valve on the outdoor unit. Get another
flare nut from the accessory bag for the indoor unit. Insert pipe through
flare nuts. Flare the connection with a flaring tool
(4). Check if the flare part is spread evenly and there are no cracks (see Fig.
4.9).
Fig. 4.9
4.3.2 Bending Pipes
(1). Extend the pipe by hand. Be careful not to crimp it.
Fig. 4.10

DC Inverter U-match Series Cassette Type Unit
15
(2).
Do not bend the pipes in an angle more than
90°.
(3). When pipes are repeatedly bent
or
stretched, the material will
weaken making it
more likely to break
. Do not bend or stretch
the pipes more than three times.
(4). For best results
, cut insulation before
bending, as shown in fig. 4.12. Bend pipe as
needed and secure insulation with tape.
Fig. 4.11
ķ. To prevent breaking of the pipe, avoid sharp bends. Bend the pipe wi
th a radius of curvature of
150mm (5-7/8inch) or more.
ĸ. If the pipe is bent repeatedly at the same place, it will break.
4.3.3 Connecting the Pipe at the Indoor Unit Side
Detach the caps and plugs from the pipes.
ķ. Be sure to attach the pipe on the indoor unit correctly.
Center the flare nut on the fitting before
tightening. Do not force the nut to turn or the threads will be damaged and the system will leak.
ĸ. Do not remov
e the flare nut until the connection pipe is to be connected so as to prevent dust
and impurities from coming into the pipe system.
When connecting the pipe to the unit or removing it from the unit, please use a
torque wrench (Fig. 4.12).
When connecting, smear both inside and outside of the flare nut with lubricant,
screw it hand tight and then tighten it with the torque wrench.
Refer to Table 4.5 to check if the wrench has been tightened properly (too tight
would mangle the nut and lead to leakage).
Examine the connection pipe to see if it leaks, then apply heat insulation sheath,
as shown in the Fig. 4.12.
Use the medium-sized sponge to insulate the coupler of the gas pipe.

DC Inverter U-match Series Cassette Type Unit
16
Fig. 4.12
Table 4.5 Flare nut tightening torque
Pipe Diameter
Tightening Torque
6mm (1/4inch)
15~30N·m (11~22ft.-lb.)
9.5mm (3/8inch)
35~40N·m (26~29ft.-lb.)
12.7mm (1/2inch)
45~50N·m (33~37ft.-lb.)
16mm (5/8inch)
60~65N·m (44~48ft.-lb.)
Be sure to connect the gas pipe after connecting the liquid pipe completely.
4.3.4 Connecting the Pipe at the Outdoor Side Unit
Tighten the flare nut of the connection pipe
at the outdoor unit valve connector. The
tightening method is the same as that as at the
indoor side
.
Fig. 4.13
4.3.5 Checking the Pipe Connections for Gas Leaks
For both indoor and outdoor unit, be sure to check the joints for gas leaks with a