Carrier 38MURA User manual

Specifications subject to change without notice.
TABLE OF CONTENTS
PAGE
A NOTE ABOUT SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
AUTO START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
ENERGY SAVING RECOMMENDATIONS . . . . . . . . . . . . . . . . . 4
CARE AND MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Scan to access French documentation:
A220698
Fig. 1 — Air Handler
NOTE TO EQUIPMENT OWNER:
Please read this Owner’s Information Manual carefully before installing and using this appliance and keep this manual for future
reference.
For your convenience, please record the model and serial numbers of your new equipment in the spaces provided. This information, along
with the installation data and dealer contact information, will be helpful should your system require maintenance or service.
UNIT INFORMATION
Model # _______________________________
Serial # ________________________________
INSTALLATION INFORMATION
Date Installed ___________________________
DEALERSHIP CONTACT INFORMATION
Company Name: ______________________
Address:_____________________________
Phone Number:________________________
Technician Name:______________________
Owner’s Manual
40MUAA
Sizes 18K to 60K

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
2
A NOTE ABOUT SAFETY
Any time you see this symbol in manuals, instructions and on the unit, be
aware of the potential for personal injury. There are 3 levels of precaution:
1. DANGER identifies the most serious hazards which will result in
severe personal injury or death.
2. WARNING signifies hazards that could result in personal injury or
death.
3. CAUTION is used to identify unsafe practices which could 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.
GENERAL
The Air Handler fan coil unit provides quiet, maximum comfort. In addition to
cooling and/or heating, the Air Handler fan coil unit, matched with an outdoor
condensing unit, filters and dehumidifies the air in the room to provide
maximum comfort.
IMPORTANT: The Air Handler fan coil unit should be installed by
authorized personnel only; using approved tubing and accessories. If
technical assistance, service or repair is needed, contact the installer.
The Air Handler fan coil unit can be set up and operated from the remote
control or the wired controller (both provided).
Operating Modes:
The Air Handler fan coil unit has four operating modes:
• FAN ONLY
• AUTO
• HEATING
• COOLING
FAN ONLY
In the FAN ONLY mode, the system filters and circulates the room air
without changing the room air temperature.
AUTO
In the AUTO mode, the system automatically cools or heats the room
according to the user-selected set point.
NOTE: AUTO mode is recommended for use on single zone
applications only. Using AUTO changeover on multi-zone applications
could set an indoor unit to STANDBY mode, indicated with two dashes (-
-) on the display, which turns the indoor unit off until all the indoor units
are in the same mode; either COOLING or HEATING.
NOTE: HEATING is the system’s priority mode. Simultaneous
HEATING and COOLING is not allowed.
HEATING
In the HEATING mode, the system heats and filters the room air.
COOLING
In the COOLING mode, the system cools, dries and filters the room air.
PERSONAL INJURY, DEATH AND / OR PROPERTY
DAMAGE HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock, or
other conditions which may cause personal injury or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified
installer or service agency must use factory-authorized kits or
accessories when modifying this product.
Read and follow all instructions and warnings, including labels
shipped with or attached to the unit before operating your new air
conditioner.
WARNING

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
3
ACCESSORIES
The system is shipped with the following accessories (see Table 1). Keep
the owner's manual in a safe place and do not discard any accessories
until the installation has been completed.
Table 1 — Accessories
A220704
Fig. 2 — Air Handler
A220705
Fig. 3 —Indoor Unit Representation
Wireless Remote Control (Included)
NOTE: The wireless remote should only be used by the installation
contractor to adjust the airflow settings in accordance with
the static pressure curves in installation manual.
Built-In 24V Interface Standard
Allows the control of the air handler with a third party thermostat (field
supplied).
Name Shape Quantity
Owner’s and Installation
Manual 2
Remote Controller 1
Batteries 2
Flare to Weld Adapter 2
Fasten Belt 2
Sponge 4
Flare Nut (18K-60K) 2
Accessories included with the outdoor unit
Drain Joint 1
Seal 1
Flare to Weld Adapter 2
Refrigerant Connecting Pipe
Drain Hose
Drain Hose

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
4
AUTO START
If the power fails while the unit is operating, the unit stores the
operating condition, and the unit automatically starts operating under
those conditions once the power is restored.
ENERGY SAVING
RECOMMENDATIONS
The following recommendations will add greater efficiency to the
ductless system:
• Select a comfortable thermostat setting and leave it at the
selected setting. Avoid continually raising and lowering the
setting.
• Keep the filter clean. Frequent cleaning may be necessary
depending on the indoor air quality.
• Use drapes, curtains or shades to keep direct sunlight from
heating the room on very hot days.
• Limit the unit’s run time by using the TIMER function.
• Do not obstruct the air intake on the front panel.
• Turn on the air conditioning unit before the indoor air becomes
too uncomfortable.
• DO NOT set the unit to excessive temperature levels.
• While cooling, close the curtains to avoid direct sunlight.
• Doors and windows should be kept closed to keep cool or warm
air in the room.
• DO NOT place objects near the air inlet and outlet of the unit.
• Clean the air filter every two weeks.
• Adjust the louvers properly and avoid direct airflow.
A220717
Fig. 4 —Close curtains, doors and windows
CARE AND MAINTENANCE
CLEANING YOUR INDOOR UNIT
Contact an authorized service technician for repair or maintenance.
Improper repair and maintenance may cause water leakage, electrical
shock, or fire and may void your warranty.
DO NOT substitute a blown fuse with a higher or lower amperage
rating fuse, as this may cause circuit damage or an electrical fire.
Ensure the drain hose is set up according to the instructions. Failure to
do so may cause leakage and result in personal property damage, fire
and electric shock.
Ensure all wires are connected properly. Failure to connect wires
according to instructions can result in electrical shock or fire.
Closing curtains during heating also
helps keep the heat in
Doors and windows should be kept closed
BEFORE CLEANING OR MAINTAINING THE UNIT
Always turn the unit off and disconnect its power supply before
cleaning or maintaining the unit.
When removing filter, do not touch metal parts in the unit. The
sharp metal edges can cut.
DO NOT use water to clean the inside of the indoor unit. This can
destroy insulation and cause an electrical shock.
DO NOT expose the filter to direct sunlight when drying. This can
shrink the filter.
CAUTION
Any maintenance and cleaning of the outdoor unit should be
performed by an authorized dealer or a licensed service provider.
Any unit repairs should be performed by an authorized dealer or a
licensed service provider.
CAUTION
MAINTAINING THE UNIT
Only use a soft, dry cloth to wipe the unit clean. If the unit is
especially dirty, you can use a cloth soaked in warm water to wipe
it clean.
DO NOT use chemicals or chemically treated cloths to clean the
unit. DO NOT use benzene, paint thinner, polishing powder or
other solvents to clean the unit. They can cause the plastic surface
to crack or deform.
DO NOT use water hotter than 104°F (40°C) to clean the front
panel. This can cause the panel to deform or become discolored.
DO NOT wash the unit under running water. Doing so creates an
electrical hazard. Clean the unit using a damp, lint-free cloth and
neutral detergent. Dry the unit with a dry, lint-free cloth.
CAUTION

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
5
CLEANING THE FILTER
The filter prevents dust and other particles from entering the indoor unit. Dust
buildup can reduce the efficiency of the air conditioner. For optimum
efficiency, clean the air filter every two weeks or more frequently if you
reside in a dusty area. Replace the filter with a new one if the filter is heavily
clogged and cannot be cleaned.
NOTE: In households with animals, you may have to periodically
wipe down the grille to prevent animal hair blocking the
unit’s airflow.
1. Remove the filter cover.
2. Remove the air filter.
3. Clean the air filter by vacuuming the surface or washing the filter in
warm water with mild detergent.
A220718
Fig. 5 —Remove the air filter cover
A220719
Fig. 6 —Cleaning filter with water or vacuum
MAINTENANCE – LONG PERIODS OF NON-USE
If you plan not to use the air conditioner for an extended period of time,
perform the following steps:
1. Clean all filters.
A220720
Fig. 7 —Clean all filters
2. Turn on the FAN function until the unit dries out completely.
A220722
Fig. 8 —Turn on the FAN function
3. Turn off the unit and disconnect the power.
A220723
Fig. 9 —Turn off the unit and disconnect the power
MAINTENANCE - PRE-SEASON INSPECTION
After long periods of non-use, or before periods of frequent use, do the
following:
1. Check for damaged wires.
A220724
Fig. 10 —Check for damaged wires
2. Clean all filters
A220720
Fig. 11 —Clean all filters
3. Check for leaks.
A220721
Fig. 12 —Check for leaks
4. Ensure nothing is blocking the air inlets and outlets.
A220725
Fig. 13 —Remove obstacles blocking air inlets/outlets

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
6
TROUBLESHOOTING
The issues in Table 2 are not malfunctions and in most cased do not require repairs.
Table 2 — Common Issues
NOTE: If an issue persists, contact a local dealer or your nearest customer service center. Provide them with a detailed
description of the unit’s malfunction as well as the unit’s model number.
SAFETY PRECAUTIONS
If any of the following conditions occur, turn off the unit
immediately:
The power cord is damaged or abnormally warm.
You smell a burning odor.
The unit emits loud or abnormal sounds.
A power fuse blows or the circuit breaker frequently trips.
Water or other objects fall into or out of the unit.
DO NOT attempt to fix these issues yourself. Contact an
authorized service provider immediately!
WARNING
Issue Possible Causes
Unit does not turn on when user
presses ON/OFF
The unit has a 3-minute protection feature that prevents the unit from overloading. The unit cannot be restarted
within three minutes after being turned off.
COOLING and HEATING models: If the Operation light and PRE-DEF (Pre-heating/ Defrost) indicators are
illuminated, the outdoor temperature is too cold and the unit’s anti-cold wind is activated to defrost the unit.
In the COOLING-only models: If the “Fan Only” indicator is illuminated, the outdoor temperature is too cold and
the unit’s anti-freeze protection activates to defrost the unit.
The unit changes from COOL/
HEAT mode to FAN mode
The unit may change its setting to prevent frost from forming on the unit. Once the temperature increases, the unit
starts operating in the previously selected mode again.
The set temperature has been reached, at which point the unit turns off the compressor. The unit continues
operating when the temperature fluctuates again.
The indoor unit emits white
mist
In humid regions, a large temperature difference between the room’s air and the conditioned air can cause white
mist.
Both the indoor and outdoor
units emit white mist
When the unit restarts in the HEAT mode (after defrosting), white mist may be emit due to moisture generated
from the defrosting process.
The indoor unit makes noises
A squeaking sound is heard when the system is OFF or in the COOL mode. The noise is also heard when the drain
pump (optional) is operating.
A squeaking sound may occur after running the unit in the HEAT mode due to expansion and contraction of the
unit’s plastic parts.
Both the indoor unit and
outdoor unit make noises
Low hissing sound during operation: This is normal and is caused by refrigerant gas flowing through both the
indoor and outdoor units.
Low hissing sound when the system starts, has just stopped running, or is defrosting. This noise is normal and is
caused by the refrigerant gas stopping or changing direction.
Squeaking sound: Normal expansion and contraction of plastic and metal parts caused by temperature changes
during operation can cause squeaking noises.
The outdoor unit makes noises The unit makes different sounds based on the current operating mode.
Dust emits from either the
indoor or outdoor unit
The unit may accumulate dust after extended periods of non-use. Dust can emit when the unit is turned on. This can
be mitigated by covering the unit during long periods of inactivity.
The unit emits a bad odor
The unit may absorb odors from the environment (such as furniture, cooking, cigarettes, etc.) which will emit
during operations.
The unit’s filters have become moldy and should be cleaned.
The outdoor unit fan does not
operate
During operation, the fan speed is controlled to optimize product operation.

40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
7
TROUBLESHOOTING (CONT)
When issues occur, please review the following common issues in Table 3 prior to contacting a service company.
Table 3 — Troubleshooting Tips
Problem Possible Causes Solution
Poor Cooling Performance
Temperature setting may be higher than the ambient
room temperature Lower the temperature setting
The heat exchanger on the indoor or outdoor unit is
dirty Clean the affected heat exchanger
The air filter is dirty Remove the filter and clean it according to instructions
The air inlet or outlet of either unit is blocked. Turn the unit to remove the obstruction and turn it back on
Doors and windows are open Ensure that all doors and windows are closed while
operating the unit
Excessive heat is generated by sunlight Close windows and curtains during periods of high heat or
bright sunshine
There are too many heat sources in the room (people,
computers, electronics, etc.) Reduce the amount of heat sources
Low refrigerant due to leak or long-term use Check for leaks, re-seal if necessary and top off the
refrigerant
The unit is not working
Power failure Wait for the power to be restored
The power is turned off Turn on the power
The fuse is burned out Replace the fuse
The unit’s 3-minute protection has been activated Wait three minutes after restarting the unit
Timer is activated Turn timer off
The unit starts and stops
frequently
There is too much or too little refrigerant in the
system Check for leaks and recharge the system with refrigerant
Incompressible gas or moisture has entered the system Evacuate and recharge the system with refrigerant
System circuit is blocked Determine which circuit is blocked and replace the
malfunctioning piece of equipment
The compressor is broken Replace the compressor
The voltage is too high or too low Install a manostat to regulate the voltage
Poor heating performance
The outdoor temperature is extremely low Use an auxiliary heating device
Cold air is entering through doors and windows Ensure that all doors and windows are closed during use
Low refrigerant due to leak or long-term use Check for leaks, re-seal if necessary and top off refrigerant

© 2022 Carrier. All rights reserved.
A Carrier Company
Edition Date: 06/22 Catalog No: OM-40MUAA-01
Replaces: New
40MUAA: Owner’s Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8