Carrier 48DU Series Instruction Manual

Turn to the Expertd
Owner's Information Manual
Fig. 1-Unit 48DU
C99001
NOTE TO EQUIPMENT OWNER:
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 #
ACCESSORIES (List type and model #)
INSTALLATION INFORMATION
Date Installed
DEALERSHIP CONTACT INFORMATION
Company Name
Address
Phone Number
Technician Name
NOTE TO INSTALLER:
This manual must be left with the equipment owner,

SAFETY CONSIDERATIONS
Installation and servicing of this equipment can be hazardous due to
mechanical and electrical components. Only trained and qualified
personnel should install, repair, or service this equipment.
Untrained personnel can perform basic maintenance functions such
as cleaning and replacing air filters. All other operations must be
performed by trained service personnel. When working on this
equipment, observe precautions in the literature, on tags, and on la-
bels attached to or shipped with the unit and other safety precautions
that may apply.
Follow all safety codes. Installation must be in compliance with lo-
cal and national building codes. Wear safety glasses, protective
clothing, and work gloves. Have fire extinguisher available. Read
these instructions thoroughly and follow all warnings or cautions
included in literature and attached to the unit.
Recognize safety information. This is the safety-alert symbol i_X
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, WARNING. and CAU-
TION. These words are used with the safety-alert symbol. DAN-
GER 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 un-
safe 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.
Note: Installer: This manual should be left with the equipment user.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in death, personal
injury and/or property damage.
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Do not use this unit if any part has been underwater.
Immediately call a qualified service technician to inspect the
unit and to replace any part of the control system which has
been underwater.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
When removing access panels or performing maintenance
functions inside your unit, be aware of sharp sheet metal parts
and screws. Although special care is taken to reduce sharp
edges to a minimum, be extremely careful when handling
parts or reaching into the unit.
UNIT INTRODUCTION
This 48DU unit is a small packaged gas heat/electric cooling system
that can utilize the comfort of gas heating packaged along with effi-
cient electric air conditioning. This unit uses Puron _>,the environ-
mentally friendly refrigerant, for cooling.
OPERATING YOUR UNIT
The operation of your unit is controlled by the Infinity _" User Inter-
face (UI). You simply program the UI and it maintains the indoor
temperature at the level you select. See UI manual for detailed in-
structions.
To better protect your investment and to eliminate unnecessary ser-
vice calls, familiarize yourself with the following facts:
To start the unit:
1. Turn on the electrical power and gas supply to unit.
2. Select temperature and set MODE control to desired mode.
To shut off unit:
Note: If the unit is being shut down because of a malfunction, call
your dealer as soon as possible.
1. Set system MODE control to OFF.
2. Turn offthe electrical pov:er, install lock-out tag and shut off
gas supply to unit.
Cooling Mode
With the SYSTEM or MODE control set to COOL, your unit will
run in cooling mode until the indoor temperature is lowered to the
level you have selected. On extremely hot days, your unit will run
for longer periods at a time and have shorter "off' periods than on
moderate days.
Gas Heating Mode
With the SYSTEM or MODE control set to HEAT, your unit will
run in heating mode until the room temperature is raised to the level
you have selected. Of course, your unit will run for longer periods
to maintain a comfortable environment on cooler days and nights
than on moderate ones.
MAINTENANCE AND SERVICE
This section discusses maintenance that should be performed on
your system. Most maintenance should be performed by your deal-
er. You. as the owner, may wish to handle some minor maintenance
for your new unit.
Routine Maintenance
All routine maintenance should be handled by skilled, experienced
personnel. Your dealer can help you establish a standard procedure.
To assure proper functioning of the unit. flow of condenser air must
not be obstructed from reaching the unit. Clearance from the top of
the unit is 48 in. (1219 mm). Clearance of at least 36 in. (914 mm)
is required on sides except the power entry side (42 in. clearance)
(1067 mm) and the duct side (12 in. minimum clearance) (305 mm).
Maintenance and Care for the Equipment Owner
Before proceeding with those things you might want to maintain
yourself, please carefully consider the following:

FIRE,EXPLOSION,ELECTRICALSHOCKHAZARD
Failuretofollowthiswarningcouldresultinpersonalinjury,
deathorpropertydamage.
1.TURNOFFELECTRICALPOWERTOYOURUNIT
BEFORE SERVICINGOR PERFORMING
MAINTENANCE.
2.Whenremovingaccesspanelsorperformingmaintenance
functionsinsideyourunit,beawareofsharpsheetmetal
partsandscrews.Althoughspecialcareistakentoreduce
sharpedgestoaminimum,beextremelycarefulwhen
handlingpartsorreachingintotheunit.
Air Filters
The air filter(s) should be checked every 3 or 4 weeks and changed
or cleaned whenever it becomes dirty. Dirty filters produce exces-
sive stress on the blower motor and can cause the motor to overheat
and shut down.
This unit must have air filters in place before it can be operated.
These filters can be located in one of at least two places. In many ap-
plications, the installer will provide return air filter grilles mounted
on the wall or ceiling of the conditioned structure. In the instance of
filter grilles, the filters can simply be removed from the grille and re-
placed.
The other typical application is an accessory filter rack installed in-
side the unit itself. The following information is given to assist in
changing filters used in these internal filter racks.
Table 1 indicates the correct filter size for your unit. Refer to Fig. 2
to access filters installed in the accessory filter rack.
Table 1--Indoor Air Filter Data
Unit Size Filter Size
48DU024-030 20x24x1 (508x610x25 mm)
48DU036 24x30x1 (610x762x25 mm)
48DU042-060 24x36x1 (610x914x25 mm)
To replace or inspect filters in accessory filter rack (See Fig. 2):
1. Remove the filter access panel using a 5/16-in. nut driver.
2. Removethe filter(s)bypullingitout oftheunit. Ifthe filter(s)
is dirty, clean or replace with a new one.
When installing the new filter(s), note the direction of the airflow
arrows on the filter frame.
If you have difficulty locating your air filter(s) or have questions
concerning proper filter maintenance, contact your dealer for in-
structions. When replacing filters, always use the same size and type
of filter that was supplied originally by the installer.
FIRE AND UNIT OPERATION HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Never operate your unit without filters in place. An
accumulation of dust and lint on internal parts of your unit can
cause loss of efficiency.
FILTER ACCESS
PANEL*
*For accessory filter rack
ACCESS PANEL
C99094
Fig. 2- Accessory Filter Rack Access Panel
(Optional Louvered Panels Shown)
Fans and Fan Motors
Periodically check the condition of fan wheels and housings and
fan-motor shaft bearings. Contact your dealer for the required
annual maintenance.
Indoor and Outdoor Coils
Cleaning of the coils should only be done by qualified service per-
sonnel. Contact your dealer for the required annual maintenance.
Condensate Drain
The drain pan and condensate drain line should be checked and
cleaned at the same time the cooling coils are checked by your deal-
er.
Compressor
All compressors are factory shipped with a normal charge of the cor-
rect type of refrigeration grade oil. A compressor should rarely re-
quire additional oil.
Condenser Fan
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Do not insert sticks, screwdrivers, or any other object into
revolving fan blades.
The fan must be kept free of all obstructions to ensure proper cool-
ing. Contact your dealer for any required service.
Electrical Controls and Wirin_
Electrical controls are difficult to check without proper instrumenta-
tion. If there are any discrepancies in the operating cycle, contact
your local dealer and request service.
Refrigerant Circuit
The refrigerant circuit is difficult to check for leaks without the prop-
er equipment. If inadequate cooling is suspected, contact your local
dealer for service.

EXPLOSIONANDBURNHAZARD
Failuretofollowthiswarningcouldresultinpersonalinjury,
deathorpropertydamage.
Systemunderpressure.Relievepressureandrecoverall
refrigerantbeforesystemrepairorfinalunitdisposal.Useall
serviceportsandopenallflow-controldevices,including
solenoidvalves.
UnitPanels
After performing any maintenance or service on the unit. be sure all
panels are fastened securely in place to prevent rain from entering
unit cabinet and to prevent disruption of the correct unit mrflow pat-
tern.
Regular Dealer Maintenance
In addition to the type of routine maintenance you might be willing
to perform, your unit should be inspected regularly by a properly
trained service technician. An inspection (preferably each year, but
at least every other year) should include the following:
1. Inspection and, if required, cleaning of the outdoor and
indoor coils.
2. Inspection and, if required, cleaning of the indoor coil drain
pan.
3. Inspection and cleaning of blower wheel housing and motor.
4. Inspection of all supply-air and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems found
should be resolved at this time.
5. Inspection of the unit base to ensure that no cracks, gaps, etc.,
exist which may cause a hazardous condition.
6. Inspection of the unit casing for signs of deterioration.
7. Inspection of all electrical wiring and components to assure
proper connection.
8. Inspection for leaks in the refrigerant circuit. Pressure check
to determine appropriate refrigerant charge.
9. Inspection of compressor oil level by service person to
ensure proper oil level is maintained in the compressor when
it is installed and running.
10. Operational check of the unit to determine working
conditions. Repair or adjustment should be made at this time.
Your servicing dealer may offer an economical service contract that
covers seasonal inspections. Ask for further details.
Complete service instructions can be found in the unit Installation.
Start-up and Service Instructions.
Warranty Certificate
Your 48DU unit has a limited warranty. Be sure to read the warranb
carefully to determine the coverage for your unit.
Befol_e you call for service...
...check for several easily-solved problems.
If insufficient heating or cooling is suspected:
( ) Check for sufficient airflow. Check the air filter for dirt. Check
for blocked return-air or supply-air grilles. Be sure they are open
and unobstructed. If these checks do not reveal the cause, call your
servicing dealer.
If your unit is not operating at all, check the following list for
easy solutions:
( ) Check to be sure that the temperature specified by your UI is set
below the indoor temperature during the cooling season or above
the indoor temperature during heating season. Be sure the UI is set
to COOL or HEAT and not OFF.
( ) If your unit still fails to operate, call your servicing dealer for
troubleshooting and repairs. Specify the model and serial numbers
of your unit. (Record them in this manual in the space provided.) If
the dealer knows exactly which unit you have, he may be able to
offer suggestions over the phone, or save valuable time through
knowledgeable preparation for the service call.
In Case of Tl_ouble
If you perform the steps above and unit performance is still unsatis-
factory, shut off the unit and call your dealer.
®
Turn to the Expertg
TO OBTAIN INFORMATION ON PARTS: Consult your installing dealer or classified section of your local telephone directory under the
"Heating Equipment" or "Air Conditioning Contractors & Systems" heading for dealer listing by brand name.
Have available the Model No., Series Letter. & Serial No. of your equipment to ensure correct replacement part.
Copyright 2007 Carrier Corporation Printed in the US.A. Edition Date: 04/07
Manufacturer reserves the right to change, at any tirne_ specifications and design without notice and without obligation. Catalol_ No: 0M48-30
Replaces: 0M48-22