Carrier 38MURA User manual

Specifications subject to change without notice.
Fig. 1 —Sizes 18K, 18K HH, 24K, 24K HH, 30K,
30K HH, 36K
Fig. 2 —Sizes 36K HH, 48K, 48K HH, 60K, 60K HH
NOTES: Read the entire instruction manual before starting the
installation. Images are for illustration purposes only.
Actual models may differ slightly. HH Denotes High Heat
Models.
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS........................................................2
MODEL NUMBER AND ACCESSORIES.....................................3
DIMENSIONS..................................................................................4
CLEARANCES ................................................................................8
INSTALLATION REQUIREMENTS .............................................9
INSTALLATION .............................................................................9
Step 1 - Check Equipment ................................................................9
Step 2 - Mount Unit ..........................................................................9
Step 3 - Condensate Drain Installation .............................................10
Step 4 - Operating Ambient..............................................................10
Step 5 - Refrigerant Piping Connections ..........................................10
Step 6 - Electrical Connections - Dip Switch Configuration............13
Step 7 - Evacuate Coil And Tubing System .....................................15
ELECTRICAL DATA......................................................................16
24V CONNECTION DIAGRAMS ..................................................16
START-UP .......................................................................................18
CARE AND MAINTENANCE........................................................18
TROUBLESHOOTING ...................................................................18
OUTDOOR UNIT DIAGNOSTIC GUIDES ...................................19
CROSSOVER SOLUTIONS............................................................20
Installation Instruction
38MURA
Residential Single Zone Heat Pump System
Sizes 18 to 60

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
2
SAFETY CONSIDERATIONS
Installing, starting up, and servicing air- conditioning equipment can be
hazardous due to system pressures, electrical components, and equipment
location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics should install,
start- up, and service this equipment.
Untrained personnel can perform basic maintenance functions such as
coil cleaning. All other operations should be performed by trained service
personnel only.
When working on the equipment, observe the precautions in the
literature and on tags, stickers, and labels attached to the equipment.
Follow all safety codes.Wear safety glasses and work gloves. Keep a
quenching cloth and a fire extinguisher nearby when brazing. Use care in
handling, rigging, and setting bulky equipment.
Read these instructions thoroughly and follow all warnings or cautions
included in the literature and attached to the unit. Consult local building
codes and National Electrical Code (NEC) for special requirements.
Recognize safety information.
This is the safety - alert symbol . When you see this symbol on the unit
and in instructions or manuals, be alert to the potential for personal injury.
Understand these signal words: DANGER, WA R N I N G , and CAUTION.
These words are used with the safety- alert symbol.
DANGER identifies the most serious hazards which will result in severe
personal injury or death.
WARNING signifies hazards which could result in personal injury or
death.
CAUTION is used to identify unsafe practices which may result in minor
personal injury or product and property damage.
NOTE is used to highlight suggestions which will result in enhanced
installation, reliability, or operation.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or
death.
Before installing, modifying, or servicing system, the main
electrical disconnect switch must be in the OFF position. There
may be more than 1 disconnect switch. Lock out and tag switch
with a suitable warning label.
WA R N I N G
EXPLOSION HAZARD
Failure to follow this warning could
result in death, serious personal injury,
and/or property damage.
Never use air or gases containing oxygen
for leak testing or operating refrigerant
compressors. Pressurized mixtures of air
or gases containing oxygen can lead to an
explosion.
WAR NI NG
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Do not bury more than 36 in. (914 mm) of refrigerant pipe in the
ground. If any section of pipe is buried, there must be a 6 in. (152
mm) vertical rise to the valve connections on the outdoor units. If
more than the recommended length is buried, refrigerant may
migrate to the cooler buried section during extended periods of
system shutdown. This causes refrigerant slugging and could
possibly damage the compressor at start-up.
CAUTION

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
3
MODEL NUMBER AND ACCESSORIES
The system is shipped with the following accessories. Use all of the
installation parts and accessories to install the system. Improper
installation may result in water leakage, electrical shock and fire, or cause
the equipment to fail. Keep the installation manual in a safe place and do
not discard any other accessories until the installation work has been
completed.
Table 1 — Accessories
Table 2 — Suction Line and Liquid Line Flare to Braze
Fig. 3 — Outdoor Unit
NOTE:
- If the outdoor unit is higher than the indoor unit, prevent rain
from flowing into the indoor unit along the connection pipe by
making a downward arc in the connection pipe before it enters
the wall to the indoor unit. This ensures that rain drips from
the connection pipe before it enters the wall.
- Piping and the interconnecting wiring are field supplied.
- Figure 3 is only a sketch. The actual model may differ slightly.
Table 3 lists the units covered in this document.
Table 3 — Unit Sizes
PART
NO. PART NAME QTY.
1 Outdoor unit 1
- Literature package including installation instructions 1
-Mounting pads for the outdoor unit (helps with vibration
prevention during unit operation) 4
-DrainJoint 1
-DrainHose 1
- Flare to Braze Adapter (See Table 2) 2
- Suction Line Reducer (Some models, see Table 2) 1
Model # Suction Line Flare
to Braze Adapter
Liquid Line Flare
to Braze Adapter
Suction Line Flare
to Flare Reducer
38MURAQ18AA3 5/8” flare
to 3/4” braze
3/8” flare
to 3/8” braze
5/8” flare
to 3/4” flare
38MURAQ24AA3 5/8” flare
to 3/4” braze
3/8” flare
to 3/8” braze
5/8” flare
to 3/4” flare
38MURAQ30AA3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ36AA3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ48AA3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ60AA3 7/8” flare
to 7/8” braze
3/8” flare
to 3/8” braze -
38MURAQ18AB3 5/8” flare
to 3/4” braze
3/8” flare to
3/8” braze
5/8” flare
to 3/4” flare
38MURAQ24AB3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ30AB3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ36AB3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ48AB3 3/4” flare
to 3/4” braze
3/8” flare
to 3/8” braze -
38MURAQ60AB3 7/8” flare
to 7/8” braze
3/8” flare
to 3/8” braze -
Ŷ2XWGRRUXQLW

CBP
SYSTEM TONS BTUH VOLTAGE -
PHASE OUTDOOR MODEL
1.50 18,000 208/230-1 38MURAQ18AA3
1.50 18,000 208/230-1 38MURAQ18AB3
2.00 24,000 208/230-1 38MURAQ24AA3
2.00 24,000 208/230-1 38MURAQ24AB3
2.50 30,000 208/230-1 38MURAQ30AA3
2.50 30,000 208/230-1 38MURAQ30AB3
3.00 36,000 208/230-1 38MURAQ36AA3
3.00 36,000 208/230-1 38MURAQ36AB3
4.00 48,000 208/230-1 38MURAQ48AA3
4.00 48,000 208/230-1 38MURAQ48AB3
5.00 60,000 208/230-1 38MURAQ60AA3
5.00 60,000 208/230-1 38MURAQ60AB3

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
4
DIMENSIONS
Table 4 — Dimensions
Fig. 4 — Size 18K
System
Size
(208/230V) Packaging
Height (H)
in (mm)
Width (W)
in (mm)
Depth (D)
in (mm)
Net Weight
lbs. (kg)
Height (H)
in (mm)
Width (W)
in (mm)
Depth (D)
in (mm)
Net Weight
lbs. (kg)
18K 21.81 (554) 31.69 (805) 12.99 (330) 75.84 (34.4) 24.21 (615) 36.02 (915) 14.57 (370) 81.35 (36.9)
18K High
Heat 26.50 (673) 35.04 (890) 13.29 (338) 102.95 (46.7) 29.13 (740) 39.17 (995) 15.67 (398) 109.79 (49.8)
24K 26.50 (673) 35.04 (890) 13.29 (338) 102.29 (46.4) 29.13 (740) 39.17 (995) 15.67 (398) 109.79 (49.8)
24K High
Heat 31.89 (810) 37.24 (946) 16.02 (407) 136.69 (62) 34.84 (885) 42.91 (1090) 19.69 (500) 145.50 (36)
30K 31.89 (810) 37.24 (946) 16.02 (407) 141.76 (64.3) 34.84 (885) 42.91 (1090) 19.69 (500) 151.46 (68.7)
30K High
Heat 31.89 (810) 37.24 (946) 16.02 (407) 159.83 (72.5) 34.84 (885) 42.91 (1090) 19.69 (500) 169.75 (77)
36K 31.89 (810) 37.24 (946) 16.02 (407) 151.68 (68.8) 34.84 (885) 42.91 (1090) 19.69 (500) 161.16 (73.1)
36K High
Heat 52.48 (1333) 37.48 (952) 16.34 (415)
227.07 (103) 58.27 (1480) 43.11 (1095) 19.49 (495) 255.73 (116)
48K 52.48 (1333) 37.48 (952) 16.34 (415) 217.59 (98.7) 58.27 (1480) 43.11 (1095) 19.49 (495) 248.68 (112.8)
48K High
Heat 52.48 (1333) 37.48 (952) 16.34 (415)
220.24 (99.9) 58.27 (1480) 43.11 (1095) 19.49 (495) 248.90 (112.9)
60K 52.48 (1333) 37.48 (952) 16.34 (415) 217.15 (98.5) 58.27 (1480) 43.11 (1095) 19.49 (495) 248.46 (112.7)
60K High
Heat 52.48 (1333) 37.48 (952) 16.34 (415) 239.86 (108.8) 58.27 (1480) 43.11 (1095) 19.49 (495) 271.61 (123.2)
A
DETAIL
A
SCALE2:1
334.162
13.16
894.715
35.23
663
26.1
890.603
35.06
71.521
2.82
337.562
13.29
73.517
2.89
122.053
4.81
R
6.026
0.24
11
0.43
672.787
26.49
379.586
14.94
346.674
13.65
106.051
4.18

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
5
DIMENSIONS (CONT)
Fig. 5 — Sizes 18K HH / 24K
4.18 [106.051]
4.81
[122.053]
26.49 [672.787]
0.43 [11]
13.29
[337.562] DETAIL A
SCALE 2:1
2.89
[73.517]
R 0.24
[6.026]
35.23
[894.71
26.1
[663]
35.06
[890.603]
2.82
[71.521]
14.94 [379.58
13.16 [334.16
13.65
[346.67

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
6
DIMENSIONS (CONT)
Fig. 6 — Sizes 24K HH / 30K / 30K HH / 36K

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
7
DIMENSIONS (CONT)
Fig. 7 — Sizes 36K HH / 48K / 48K HH / 60K / 60K HH
41(1045) W1
37.5(952) W
15.9(404) B
17.6(448) C
52.5(1333) H
16.3(415) D
25(634) A
2
.9(74)
27.9(708)
38.4(976)

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8
CLEARANCES
Fig. 8 — Clearances
Table 5 — Clearance Dimensions
NOTE: The outdoor unit must be mounted at least 2in (50mm) above the maximum anticipated snow depth.
Fig. 9 —Clearances for multiple units
UNIT MINIMUM VALUE
IN. (MM)
A 24 (610)
B 24 (610)
C 24 (610)
D 4 (101)
E 4 (101)
DB
AE
C
Air inlet
Air outlet
59in (150cm)
or more on a
multiple parallel
unit arrangement
24in (61cm) or more on a single parallel unit arrangement
59in (150cm)
or more when
facing each other
Blowing into the air-inlet of other
condenser shall be avoided.
24in (60cm)
or more
19in (48cm) or more on
a multiple parallel unit
arrangement 4in (10cm)
or more on a single
parallel unit arrangement
9.8in (25cm) or more for proper airflow
24in (61cm) or more is recommended
for service
59in (150cm)
or more when
facing each other
Blowing into the air-inlet of other
condenser shall be avoided.
59in (150cm)
or more

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
INSTALLATION REQUIREMENTS
• A location which is convenient to installation and not exposed to
strong winds.
• A location which can bear the weight of the outdoor unit and where
the outdoor unit can be mounted in a level position.
• A location which provides appropriate clearances (see Fig. 8).
• Allow sufficient space for airflow and service of the unit. See Fig. 8
for the required minimum distances between the unit or walls.
NOTE: DO NOT install the indoor or outdoor units in a location with
special environmental conditions.
INSTALLATION
Step 1 - Check Equipment
Unpack the unit and move to the final location. Remove the carton, taking
care not to damage the unit. Inspect the equipment for damage prior to
installation. File a claim with the shipping company if the shipment is
damaged or incomplete.
Locate the unit rating plate which contains the proper installation
information. Check the rating plate to ensure the unit matches the job
specifications.
Step 2 - Mount Unit
1. Select the installation location of the outdoor unit following the
installation requirements. To prevent high wind exposure, install the
outdoor unit with the air inlet side facing the wall (see fig 10).
Fig. 10 — High Wind Installation
2. Use a rigid base to support the unit in a level position. If conditions or
local codes require the unit be attached to a pad, tie down bolts should
be used and fastened through knockouts provided in unit base pan. For
hurricane tie downs, contact distributor for details and PE (Professional
Engineer) Certification, if required.
PRODUCT INSTALLATION
• Installation must be performed by an authorized dealer or
specialist. A defective installation can cause water leakage,
electrical shock, or fire.
• The installation must be performed according to the installation
instructions. Improper installation can cause water leakage,
electrical shock, or fire. (In North America, installation must be
performed in accordance with the requirements of NEC or CEC
by authorized personnel only.)
• Contact an authorized service technician for repair or
maintenance of this unit. This appliance must be installed in
accordance with local codes.
• Only use the included accessories, parts, and specified parts for
installation. Using non-standard parts can cause water leakage,
electrical shock, fire, or unit failure.
• To prevent exposure to wind, install the outdoor unit with its air
inlet side facing the wall
• Install drainage piping according to the instructions in this
manual. Improper drainage may cause water damage to your
home and property.
•DO NOT install the unit in a location that may be exposed to
combustible gas leaks. If combustible gas accumulates around
the unit, it may cause a fire.
•DO NOT turn on the power until all work has been completed.
• When moving or relocating the system, consult experienced
service technicians for the disconnection and re-installation of
the unit.
WA R N I N G
Strong
wind
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
In regions with snowfall and cold temperatures, avoid installing
the outdoor unit in areas where it can be covered by snow.
Blocking the air intake may result in reduced airflow, significantly
reduced performance and damage to the equipment.
CAUTION

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
10
Step 3 - Condensate Drain Installation
NOTE: Install drains must meet local sanitation codes.
Install the outdoor unit drain joint
Fit the seal into the drain joint, then insert the drain joint into the base pan
hole of the outdoor unit. Rotate 90° to securely assemble them. Connect
the drain joint with an extension drain hose to avoid condensate from
draining off the outdoor unit during the heating mode.
Fig. 11 — Drain Joint
NOTE: Images are for illustration purposes only.
NOTE: Basepan built-in with multiple holes for proper draining
during defrost. For applications where it is required to seal
these holes, and re-direct the condensate drain, rubber plugs
are available through RCD.
Table 6 — Base Pan Rubber Plugs
Step 4 - Operating Ambient
Step 5 - Refrigerant Piping Connections
Table 7 — Piping and Refrigerant
Base pan hole of
outdoor unit
Drain fitting
Seal
Seal
OUTDOOR UNIT MODEL
NUMBER
PER UNIT
BASE PAN RUBBER PLUGS
RCD PART NUMBER
38MURAQ18AA3
38MURAQ18AB3
38MURAQ24AA3
38MURAQ24AB3
38MURAQ30AA3
38MURAQ30AB3
38MURAQ36AA3
38MURAQ36AB3
38MURAQ48AA3
38MURAQ48AB3
38MURAQ60AA3
38MURAQ60AB3
12600801A00077
EQUIPMENT DAMAGE HAZARD
In cold climates, ensure the drain hose is as vertical as possible to
ensure swift water drainage. If water drains too slowly, it can freeze
in the hose and flood the unit.
CAUTION
OPERATING RANGE AND HUMIDITY HIGH HEAT
MODELS
REGULAR
MODELS
Operating Range
Cooling Outdoor
Min - Max DB
°F -22~130 5~130
°C -30~55 -15~55
Heating Outdoor
Min - Max DB
°F -22~86 -5~86
°C -30~30 -15~30
Operating Humidity % 0~80 0~80
System Size 18K 18K High
Heat 24K 24K High Heat 30K 30K High Heat 36K 36K High Heat 48K 48K High Heat 60K 60K High Heat
(208/230 V)
Min. Piping Length ft.(m) 9.8 (3)
Standard Piping Length ft.(m) 24.6 (7.5)
Max. outdoor-indoor
height difference
(OU higher than IU)
ft.(m) 65.6 (20) 65.6 (20) 82 (25) 82 (25) 82 (25) 82 (25) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30)
Max. outdoor-indoor
height difference
(IU higher than OU)
ft.(m) 65.6 (20) 65.6 (20) 82 (25) 82 (25) 82 (25) 82 (25) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30) 98.4 (30)
Suction Pipe
(size - connection type) in (mm) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø3/4” (19) ø7/8” (22) ø7/8” (22)
Liquid Pipe (
size-connection) in (mm) ø3/8” (9.52)
Refrigerant Type Type R410A
Charge Amount lb. (kg) 3.53 (1.6) 5.07 (2.3) 4.63 (2.1) 6.39 (2.9) 6.72 (3.05) 8.38 (3.8) 8.16 (3.7) 10.36 (4.7) 10.4 (4.7) 10.58 (4.8) 10.8 (4.9) 10.58 (4.8)
Total Maximum Piping
Length per system ft. (m 98.4(30) 98.4(30) 164 (50) 164 (50) 164 (50) 164 (50) 213 (65) 213 (65) 213 (65) 213 (65) 213 (65) 213 (65)

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
11
IMPORTANT: The suction line must be insulated. Use
refrigeration grade tubing ONLY. No other type of tubing may
be used. Use of other types of tubing will void the
manufacturer's warranty.
• The minimum refrigerant line length between the indoor and outdoor
unit is 10 ft. (3m).
• All outdoor units have an electronic expansion valve to manage the
refrigerant flow of the fan coil connected.
• Do not open the service valves or remove the protective caps from the
tubing ends until all connections are made.
• Bend the tubing with bending tools to avoid kinks and flat spots.
• Keep the tubing free of dirt, sand, moisture, and other contaminants to
avoid damaging the refrigerant system.
• Avoid sags in the suction line to prevent the formation of oil traps.
• Insulate the suction line with a minimum 3/8-in. (10 mm) wall thermal
pipe insulation. Inserting the tubing into the insulation before making
the connections will save time and improve installation quality.
Use the following steps to connect the refrigerant piping:
1. Run the interconnecting piping from the outdoor unit to the indoor unit.
2. Connect the refrigerant piping and drain line outside the indoor unit.
Complete the pipe insulation at the flare connection then fasten the
piping and wiring to the wall as required. Completely seal the hole in
the wall.
3. Cut tubing to the correct length.
When preparing refrigerant pipes, take extra care to cut and flare
them properly. This ensures efficient operation and minimizes the
need for future maintenance.
a. Measure the distance between the indoor and outdoor units.
b. Using a pipe cutter, cut the pipe a little longer than the measured
distance.
c. Make sure the pipe is cut at a perfect 90° angle.
Fig. 12 —Pipe Cutting
4. Remove the Burrs
Burrs can affect the air-tight seal of the refrigerant piping connection.
Therefore, they must be completely removed. To remove:
a. Hold the pipe at a downward angle to prevent burrs from
falling into the pipe.
b. Using a reamer or deburring tool, remove all burrs from the cut
section of the pipe.
Fig. 13 — Deburring Tool
5. Flare the Pipe Ends
Proper flaring is essential to achieving an airtight seal.
a. After removing the burrs from the cut pipe, seal the ends with PVC
tape to prevent foreign materials from entering the pipe.
b. Sheath the pipe with insulating material.
c. Place factory flare nut on pipe facing the proper direction. Make
sure they are facing the right direction. Once the ends are flared, it
is impossible to put them on or change their direction.
Fig. 14 — Copper pipe and flare nut
d. Remove the PVC tape from ends of pipe when ready to perform the
flaring work.
e. Clamp the flare block on the end of the pipe. The end of the pipe
must extend beyond the flare form.
f. Place the flaring tool onto the form.
All field piping must be completed by a licensed technician and
must comply with the local and national regulations.
When the system is installed in a small room, measures must be
taken to prevent the refrigerant concentration in the room from
exceeding the safety limit in the event of refrigerant leakage. If the
refrigerant leaks and its concentration exceeds its proper limit,
hazards due to lack of oxygen may result.
When installing the refrigeration system, ensure that air, dust,
moisture or foreign substances do not enter the refrigerant circuit.
Contamination in the system may cause poor operating capacity,
high pressure in the refrigeration cycle, explosion or injury.
Ventilate the area immediately if there is refrigerant leakage
during the installation.
Leaked refrigerant gas is hazardous. Ensure there is no refrigerant
leakage after completing the installation work.
WA R N I N G
DO NOT install the connecting pipe until both the indoor and
outdoor units have been installed.
Insulate the suction line to prevent condensation.
CAUTION
Oblique Rough
Warped
90°
DO NOT DEFORM PIPE WHILE CUTTING
Be extra careful not to damage, dent, or deform the pipe while
cutting. This will drastically reduce the heating efficiency of the unit.
CAUTION
Pipe
Reamer
Point down
Flare nut
Copper pipe

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
12
g. Turn the handle of the flaring tool clockwise until the pipe is fully
flared. Flare the pipe in accordance with the dimensions in Table 8.
Fig. 15 — Flare Shape
Table 8 — Tightening Torque
NOTE: Use both a backup wrench and a torque wrench when
connecting or disconnecting pipes to or from the unit.
h. Remove the flaring tool and flare block, then inspect the end of
the pipe for cracks and even flaring.
6. Connect the Pipes
Connect the copper pipes to the indoor unit first, then connect the
pipes to the outdoor unit. Connect the low-pressure pipe first, then
connect the high pressure pipe.
a. Align the center of the two pipes that you will connect.
Fig. 16 — Align the center of the two pipes
b. Tighten the flare nut as much as possible by hand.
c. Using a wrench, grip the nut on the unit tubing.
d. While firmly gripping the nut, use a torque wrench to tighten
the flare nut according to the torque values listed in Table 8.
Fig. 17 — Torque wrench with backup wrench
All tubing bends should be performed with a properly sized tubing bender
to prevent kinking or damaging the tubing.
e. After connecting the copper pipes to the indoor unit, wrap the
power cable, signal cable and the piping together with binding
tape.
NOTE: While bundling these items together, DO NOT intertwine or
cross the signal cable with any other wiring.
f. Thread this lineset through the wall and connect it to the
outdoor unit.
g. Insulate the suction line, including the outdoor unit valves.
NOTE: DO NOT open the service valves until pressure test is
complete.
7. Filter Drier (Heat Pump Drier ONLY)
Refer to Fig. 18 and install the drier as follows:
1.Cut a minimum 4" length of 3/8 tubing and assemble:
a. 3/8” adapter
b. short tubing
c. filter drier
d. lineset
2.Wrap filter drier with damp cloth.
3. Flow nitrogen.
4. Braze assembled components from step 1.
Fig. 18 — Filter Drier Components
The filter drier must be replaced whenever the refrigeration system is
exposed to the atmosphere.
Only use factory specified liquid-line filter driers with rated working
pressures less than 600 psig.
NOTE: Do not install a suction-line filter drier in liquid line.
BRASS
FLARE SIZES
RECOMMENDED
SEATING TORQUE FOR
BRASS FLARE NUTS
FLARE DIMENSIONS (A)
(INCH/MM)
In (mm) Ft-Lbs N-M Min Max
Ø3/8 (9.52) 23.6-28.8 32-39 0.52/13.2 0.53/13.5
Ø3/4 (19) 49.4-74.5 67-101 0.91/23.2 0.93/23.7
Ø7/8 (22) 62.7-81.1 85-110 1.04/26.4 1.06/26.9
R0.4~0.8
45qr2
90 q
r4
A
Pipe
Indoor unit tubing Flare nut
Wrap insulation around the piping. Direct contact with the bare
piping may result in burns or frostbite. Ensure the pipe is properly
connected. Over tightening may damage the bell mouth and under
tightening may lead to leakage.
CAUTION

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
13
8. Brazing Adapter (Optional)
When flare to braze adapter is used, follow these steps:
a. Refer to the liquid line and gas line connection O.D. sizes in
Table 7 based on the model being installed. Cut and deburr the
tubing (review “Remove the Burrs on page 11.) to prepare it
for brazing. Setup the nitrogen apparatus and connect to the
outside unit to flow nitrogen while brazing. Braze the tubing
and any fittings to obtain a proper seal.
b. Adjust the nitrogen apparatus to pressurize the system. Pressure
test the system to a maximum of 500 psig for at least 60
minutes.
c. Insulate suction line completely, including the outdoor unit
valves.
9. Pressure Test Piping
NOTE: Use refrigeration gauges that are pressure rated for R410a
refrigerant.
a. Attach low side gauge hose to the 5/16” Schrader valve
on the outdoor unit service valve.
b. Attach the charging hose to the regulator on the dry nitrogen
tank.
c. Preset the nitrogen regulator to 550 psi.
d. Slowly pressurize the line set until the low side gauge reads 500
psi. Do not exceed 550 psi.
e. Close all the valves on the nitrogen tank and gauges.
f. Allow the pressure test to stand for a minimum of 30 minutes.
g. If the pressure holds, release the nitrogen and proceed with
“Step 6 - Electrical Connections - Dip Switch Configuration on
page 13.
h. If the pressure goes down in the 30 minute delay, leak check the
tubing and flare fittings to identify the source of the leak.
Return to Step C, above.
Additional Refrigerant Requirements
Step 6 - Electrical Connections - Dip Switch
Configuration
Install All Power and Interconnecting Wiring to
Outdoor Units
1. Mount the outdoor power disconnect.
2. Run the power wiring from the main box to disconnect per NEC and
local codes.
3. Remove the field wiring cover from the unit by loosening the screws.
4. Remove the caps on the conduit panel.
5. Connect the conduit to conduit panel (see Fig. 19).
6. Properly connect both the power supply and control lines to the
terminal block per the connection diagram for the appropriate unit
capacity and voltage.
7. Ground the unit in accordance with NEC and local electrical codes.
8. Use the lock nuts to secure the conduit.
9. Reinstall the field wiring cover.
Fig. 19 —Field Wiring
System
Size
Max. Piping Length with no
additional refrigerant
charge per System
Additional
refrigerant
charge
Total Maximum
Piping Length per
system
ft. (m) Oz/ft (g/m) ft. (m)
18K
24.6 (7.5) 0.69 (65)
98 (30)
24K - 30K 164 (50)
36K - 60K 213 (65)
Only use Dry Nitrogen to pressure test refrigerant systems. Use of
other gases can result in injury, property damage or death.
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Be sure to comply with local codes while running wire from
indoor unit to outdoor unit.
Every wire must be connected firmly. Loose wiring may cause the
terminal to overheat or result in unit malfunction. A fire hazard
may also exist. Therefore, ensure all wiring is tightly connected.
No wire should be allowed to touch the refrigerant tubing,
compressor or any moving parts.
Disconnecting means must be provided and shall be located
within sight and readily accessible from the air conditioner.
Connecting cable with the conduit shall be routed through hole in
the conduit panel.
CAUTION
Wire Cover
Over 1.57in.(40mm)
Terminal block
Conduit panel
Conduit fitting
Connecting cable
Select the appropriate conduit opening for the
wire size used.
An approved and listed fitting must be used to securely affix
conduit in accordance with NEC and local codes.
WARNING

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
14
Wiring
All wires must be sized per NEC (National Electrical Code) or CEC
(Canadian Electrical Code) and local codes. Use Electrical Data table
MCA (minimum circuit amps) and MOCP (maximum over current
protection) to correctly size the wires and the disconnect fuse or breakers
respectively.
Power wiring
1. Remove the electric cover of the outdoor unit.
2. Connect the fork terminal to the terminals.
3. Match the wire labels with the labels on the terminal block.
4. Firmly screw the fork terminal of each wire to its corresponding
terminal.
5. Insulate unused wires with electrical tape. Keep them away from any
electrical or metal parts.
6. Reinstall the cover of the electric control box
Fig. 20 —Remove Electrical Cover
Fig. 21 — High Voltage Power Connections
Communication wiring
There are two options available to establish communication between the
outdoor unit and approved indoor unit.
Fig. 22 —Option 1: Non-polarity RS485 Communication
Fig. 23 —Option 2: 24V Communication
NOTES:
1. Do not use the thermostat wire for any RS-485 connection between
indoor and outdoor units.
2. All connections between the indoor and outdoor units must be made as
shown in Figures 22 - 23.
OPTIONS COMMUNICATION TYPE RECOMMENDED CABLE SIZE
1Non-Polarity RS485
Communication (S1 - S2) 16 AWG (stranded shielded)
224V communication 18 AWG 8 conductor thermostat
wire
Cover
Screw
L1
TO POWER SOURCE
L2
ON
S1
1 2 3 4
CN6
S1
R C Y1 Y2 L
S2 B W D
TO INDOOR UNIT
ON
Outdoor Unit
Only Mode
1 2 3 4
CN6
TO 24V THERMOSTAT
S1
R C Y1 Y2 L
S2 B W D
S1
Power needs to be OFF before dip switch adjustments.
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation. Wires should be sized based on NEDC and
local codes.
WARNING
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation. Be sure to comply with local codes while
running wire from the indoor unit to the outdoor unit. Every wire
must be connected firmly. Loose wiring may cause the terminal to
overheat or result in unit malfunction. A fire hazard may also exist.
Ensure all wiring is tightly connected.
No wire should touch the refrigerant tubing, compressor or any
moving parts. Disconnecting means must be provided and shall be
located within sight and readily accessible from the air conditioner.
Connecting cable with conduit shall be routed through the hole in
the conduit panel.
CAUTION

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
15
Step 7 - Evacuate Coil And Tubing System
Refrigerant tubes and the indoor coil should be evacuated using the
recommended 500 microns deep vacuum method. The alternate triple
evacuation method may be used if the procedure outlined below is
followed.
NOTE: Always break a vacuum with dry nitrogen.
Using Vacuum Pump
1. Completely tighten flare nuts A, B, C, D. Connect the manifold gage
charge hose to a charge port of the low side service valve (see Fig. 24).
2. Connect the charge hose to vacuum pump.
3. Fully open the low side of manifold gage (see Fig. 25).
4. Start the vacuum pump.
5. Evacuate using either the deep vacuum or triple evacuation method.
6. After evacuation is complete, fully close the low side of manifold gage
and stop the vacuum pump operation.
7. The factory charge contained in the outdoor unit is good for up to 25 ft.
(8 m) of line length. For refrigerant lines longer than 25 ft. (8 m), add
refrigerant, up to the allowable length.
8. Disconnect the charge hose from the charge connection of the low side
service valve.
9. Fully open service valves B and A.
10. Securely tighten the service valve caps.
Fig. 24 — Service Valve
Fig. 25 — Manifold
Evacuation
Evacuation of the system will remove air or nitrogen (non-condensables) as
well as moisture. A proper vacuum will assure a tight, dry system before
charging with refrigerant. The two methods used to evacuate a system are the
deep vacuum method and the triple vacuum method.
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a vacuum
of 500 microns and a vacuum gauge capable of accurately measuring this
vacuum depth. The deep vacuum method is the most positive way of assuring a
system is free of air and moisture (see Figure 26).
Fig. 26 — Deep Vacuum Graph
Triple Evacuation Method
The triple evacuation method should be used when vacuum pump
is not capable of pumping down to 500 microns and system does not
contain any liquid water. Refer to Fig. 27 and proceed as follows:
1. Attach refrigeration gauges and evacuate system down to 28 in. of mercury
and allow pump to continue operating for an additional 15 minutes.
2. Close service valves and shut off vacuum pump.
3. Connect a nitrogen cylinder and regulator to system and flow nitrogen
until system pressure is 2 psig.
4. Close service valve and allow system to stand for 1 hour. During this
time, dry nitrogen will be able to diffuse throughout the system
absorbing moisture.
5. Repeat this procedure as indicated in Fig. 27. System is now free of any
contaminants and water vapor.
Fig. 27 — Triple Evacuation Method
Final Tubing Check
Check to be certain factory tubing on both the indoor and outdoor unit has
not shifted during shipment. Ensure tubes are not rubbing against each
other or any sheet metal. Pay close attention to the feeder tubes, making
sure wire ties on feeder tubes are secure and tight.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Never use the system compressor as a vacuum pump.
CAUTION
Outdoor Unit Indoor UnitRefrigerant
Service Valve
Low Side
High Side
A
B
C
D
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuum
pump
Low side valve
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
SYSTEM TIGHT
EVACUATE MOISTURE
TIGHT DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
RELEASE CHARGE INTO SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
16
ELECTRICAL DATA
Table 9 — Electrical Data
LEGEND
FLA - Full Load Amps
MCA - Minimum Circuit Amps
MOPA - Maximum Overcurrent Protection Ampacity
24V CONNECTION DIAGRAMS
Table 10 — Terminal Function
NOTE: Terminal D is now energized when the outdoor unit goes into defrost mode and can be used to enable electric heat. This feature is not
available when the outdoor unit communicates with the indoor unit via non-polarity RS485 Communication S1-S2.
OUTDOOR
UNIT
208/230-1-60 COOLING HEATING
Minimum
Circuit
Ampacity
(MCA)
Maximum
Overcurrent
Protection
Ampacity
(MOCP)
MAX-MIN
VOLTAGE
RANGE
Running
Current
Power
Consumption Power Factor Running Current Range
Power
Consumption Power Factor
18K 16 20 253-187 7.5 1620 97.2 6.7 1510 96.9
18K HH 16 20 253-187 6.5 1430 71.5 7 1550 71.5
24K 19 30 253-187 9.7 2120 98.9 9.8 2150 98.8
24K HH 20.5 35 253-187 9.4 1920 94.6 9.13 2040 94.5
30K 20 35 253-187 12.2 2760 95.8 12.4 2850 96.3
30K HH 23 35 253-187 12.4 2720 96.4 12.5 2780 96.7
36K 24 40 253-187 15.82 3750 97.2 16.12 3496 96.8
36K HH 41 50 253-187 14.8 3300 97.8 14.8 3400 97.6
48K 34 50 253-187 21.9 5046 98 23.3 5373 98.4
48K HH 42 50 253-187 24.2 5530 99 21.5 4880 98.9
60K 34 60 253-187 23.8 5644 98.3 20.9 4959 97.7
60K HH 42 60 253-187 26.7 6110 97.9 21.5 4940 97.1
R 24V Power Connection
C Common
Y1 Low Demand
Y2 High Demand
B Heating Reversing Valve
W Heating Control
D Defrost - (24V output signal)
L System Fault - (24V output signal)

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
17
Fig. 28 —Wiring for 4H and 2C Thermostat
Fig. 29 —Wiring for 3H and 1C Thermostat
Fig. 30 —Wiring for 3H and 2C Thermostat
Fig. 31 —Wiring for 3H and 2C Thermostat
Fig. 32 —Wiring for 2H and 2C Thermostat
Fig. 33 —Wiring for 2H and 1C Thermostat
Fig. 34 —Wiring for 1H and 1C Thermostat
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT OUTDOOR UNIT
DH
O/B
W2
Y2
Y1
G
L
C
R
W1/E
THERMOSTAT
Y/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT
DH
OUTDOOR UNIT
O/B
W2
Y
G
L
C
R
W1/E
THERMOSTAT Y
/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT
DH
O/B
Y2
Y1
G
L
C
R
E
THERMOSTAT
OUTDOOR UNIT
Y
/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT
DH
O/B
Y2
Y1
G
L
C
R
W1/E
THERMOSTAT
OUTDOOR UNIT
Y/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT OUTDOOR UNIT
O/B
Y2
Y1
G
C
R
THERMOSTAT
Y
/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT OUTDOOR UNIT
O/B
Y
G
C
R
W/E
THERMOSTAT
Y
/
Y2
R L G B W E
CY1
DH W1 W2 R B W D L
CY1 Y2
INDOOR UNIT
OUTDOOR UNIT
O/B
Y
G
C
R
T
HERMOSTAT
Y
/
Y2
S4-1:
Default ON: For single stage supplemental heat, W1
and W2 are connected.
OFF: For dual stage supplemental heat, W1 and W2
are controlled independently. feature is enabled
through thermostat.
S4-2:
Default ON: Dehumidification control not available.
OFF: Dehumidification feature is enabled through
thermostat.
Note: Dip switches are located on a compatible indoor unit. Refer to the indoor unit
installation manual for additional information. A heat pump thermostat is
required for all above thermostat configurations.

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
18
START-UP
Test Operation
Perform a test operation after completing a gas leak and electrical safety
check. Review the indoor unit installation instructions and owner's
manual for additional start up information.
System Checks
1. Conceal the tubing where possible.
2. Ensure that the drain tube slopes downward along its entire length.
3. Ensure all required piping and connections are properly insulated.
4. Fasten the tubes to the outside wall, when possible.
5. Seal the hole through which the cables and tubing pass.
Outdoor Unit
1. Are there unusual noises or vibrations during operation?
Explain the Following Items to the Customer (with the aid of the
Owner's Manual):
2. Explain care and maintenance.
3. Present the installation instructions to the customer.
CARE AND MAINTENANCE
To help ensure high performance and minimize possible equipment
failure, periodic maintenance must be performed on this equipment.
Maintenance frequency may vary depending upon geographic areas.
TROUBLESHOOTING
For ease of service, the systems are equipped with diagnostic code
display LEDs on both the indoor and outdoor units. The outdoor
diagnostic display are two LEDs (Red and Green) on the outdoor unit
board and is limited to very few errors. The indoor diagnostic display is a
combination of flashing LEDs on the display panel or the front of the
unit.
There may be a few error codes displayed in the indoor unit that might
relate to the outdoor unit’s problems. If possible, always check the
diagnostic codes displayed on the indoor unit first.

38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
19
OUTDOOR UNIT DIAGNOSTIC GUIDES
For ease of service, systems are equipped with diagnostic code display LEDs on the indoor and outdoor units. Outdoor diagnostic is displayed on the
outdoor unit microprocessor board. There may be a few error codes displayed in the indoor unit that might relate to the outdoor unit's problems. If
possible, always check the diagnostic codes displayed on the indoor unit first. The diagnostic codes displayed on the outdoor units are listed in
Table 11.
Table 11 — Outdoor Unit Diagnostic Codes
NOTE: It is normal to display DF or FC, not a malfunction. For additional diagnostic information, refer to the service manual.
DISPLAY ERROR INFORMATION DISPLAY ERROR INFORMATION
EC5C High pressure sensor failure PC0F PFC module protection
EC57 Refrigerant pipe temperature sensor error PC0L Low temperature protection of outdoor unit
EL01 Communication malfunction between indoor and outdoor
units PC10 Outdoor unit low AC voltage protection
EC50 Outdoor temperature sensor error PC11 Outdoor unit main control board DC bus high voltage
protection
EC51 Outdoor EEPROM error PC12 Outdoor unit main control board DC bus high voltage
protection /341 MCE error
EC52 Condenser coil temperature sensor (T3) malfunction PC30 System high pressure protection
EC53 Outdoor ambient temperature sensor (T4) malfunction PC31 System low pressure protection
EC54 Compressor discharge temperature sensor TP has an
open or short circuit PC40 Communication error between outdoor main chip and
compressor driven chip
EC07 Outdoor DC fan motor malfunction/fan speed out of
control PC42 Compressor start failure of outdoor unit
EC71 Over current failure of outdoor DC fan motor PC43 Outdoor compressor lack phase protection
EC72 Lack phase failure of outdoor DC fan motor PC44 Outdoor unit zero speed protection
EL16 Communication malfunction between outdoor unit main
board and outdoor transit board PC45 Outdoor unit IR chip drive failure
PC00 Inverter module (IPM) protection PC46 Compressor speed has been out of control
PC02 Top temperature protection of compressor PC49 Compressor overcurrent failure
PC06 Discharge temperature protection of compressor PH90 High temperature protection of Evaporator
PC08 Outdoor overcurrent protection PH91 Low temperature protection of Evaporator
PC0A High temperature protection of condenser LC06 High temperature protection of Inverter module (IPM)

© 2022 Carrier. All rights reserved.
Edition Date: 12/22 Catalog No: IM-38MURA-03
Replaces: IM-38MURA-02
38MURA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
20
CROSSOVER SOLUTIONS
TESTED AHRI COMBINATION RATINGS
SCENARIO # 1: SINGLE ZONE OUTDOOR UNITS 38MURA WITH APPROVED FURNACES/CASED COILS
Fig. 35 — Wiring for 4H and 2C Thermostat
Fig. 36 — Wiring for 3H and 2C Thermostat
Fig. 37 — Wiring for 2H and 1C Thermostat
NOTE: If the outdoor condensing unit initiates defrost cycles frequently, then it is recommended to adjust the “thermal balance point” to a
temperature that would decrease the recurrence of these cycles and prevent cold air blowing during the duration of the defrost cycle.
The thermal balance point is the outdoor ambient temperature at which the heat pump can no longer provide sufficient heating to the
space on its own and compromises the reliability of the compressor.
For AHRI ratings certificates, refer to the AHRI directory http://www.ahridirectory.org.
Additional ratings and system combinations can be accessed via the Carrier database at: www.MyCarrierRatings.com.