48EZ---A and 48VT---A
Comfort™ and Performance™ 13 and 14 SEER
Single Packaged Hybridr Heat Dual Fuel System
With Puron (R---410A) Refrigerant
Single and Three Phase
2 --- 5 N om i n a l Ton s ( Si ze s 24 --- 60)
Owner’s Information Manual
A09034
A09033
48EZ--A Without Economizer
48VT--A Without Economizer
A10078
48VT--A
A10077
48VT--A with Economizer
Fig. 2 -- Unit 48VT--A
48EZ--A With Economizer
Fig. 1 -- Unit 48EZ--A
1
UNIT INTRODUCTION
!
WARNING
The 48EZ--A and 48VT--A units are small packaged gas
heat/electric heat pump systems that can utilize both the efficiency
of heat pump heating and the comfort of gas heating. The system
will optimize for ideal heating, depending on several factors. This
unit uses Puron®, the ozone friendly refrigerant, for cooling and
heat pump heating.
FIRE AND EXPLOSION HAZARD
Failure to follow this hazard warning could result in
personal injury, death and/or property damage.
What to do if you smell gas:
1. Do not try to light any appliance.
2. Do not touch any electrical switch; do not use any phone
in your building.
Starting or Shutting Off Unit
NOTE: Your combination heating/cooling unit is equipped with
an automatic direct spark ignition and power combustion blower.
To start unit gas heat:
Refer to Fig. 3 for location of unit front access panel. Refer to Fig.
4 for location of gas valve. Refer to Fig. 5 while proceeding with
the following steps.
3. Leave the building immediately.
4. Immediately call your gas supplier from a nearby phone.
Follow the gas supplier’s instructions.
5. If you cannot reach your gas supplier, call the fire
department.
1. Set the temperature selector on room thermostat to the low-
est temperature setting and set system switch to Emergency
Heat.
!
WARNING
2. Close the external manual gas shutoff valve.
3. Turn off the electrical supply to the unit.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury and/or death.
4. Remove the control access panel with a 5/16--in. nut driver.
(See Fig. 3.)
Before performing recommended maintenance, be sure the
main power switch to unit is turned off and lock--out tag is
installed.
!
WARNING
FIRE,
EXPLOSION,
ELECTRICAL
SHOCK
HAZARD
Failure to follow this hazard warning could result in
personal injury, death and/or property damage.
1. Do not turn off the electrical power to unit without first
turning off the gas supply.
2. Before attempting to start the gas heating section,
familiarize yourself with all the procedures that must be
followed.
Control
Access
Panel
Blower
Access
Panel
Filter Access Panel
For Accessory Filter Rack
Compressor
Access
Panel
A09213
WARNING
FIRE, EXPLOSION HAZARD
Fig. 3 -- Unit Access Panels
!
5. Move the selector switch on the internal gas valve to the
OFF position and wait 5 minutes.
Failure to follow this warning could result in personal
injury, death, and/or property damage.
6. Move the selector switch on the internal gas valve to the ON
position.
Do not attempt to light by hand.
7. Replace the control access panel.
8. Turn on the electrical supply to unit.
9. Open the external manual gas shutoff valve.
!
CAUTION
10. Set the temperature selector on room thermostat slightly
above room temperature to start unit. The induced--draft
combustion air fan will start. Main gas valve will open and
main burners should ignite within 5 seconds. If the burner
does not light within 5 seconds, the ignition module will go
into a Retry Mode after a period of approximately 22
seconds (following the 5--second ignition period). If the
burners do not light within 15 minutes of the initial call for
heat, there is a lockout.
CUT HAZARD
Failure to follow this caution may result in personal injury.
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.
3
11. Set the temperature selector on room thermostat to desired
setting.
5. Move the selector switch on the internal gas valve to the
OFF position.
6. Replace the control access panel.
WARNING
To start unit electric cooling:
Refer to Fig. 7 while proceeding with the following steps.
!
FIRE AND EXPLOSION HAZARD
1. Set the temperature selector on room thermostat to highest
temperature setting and set system SWITCH to OFF.
2. Close the external manual shutoff valve, if not already
closed.
Failure to follow this warning could result in personal
injury, death, and/or property damage.
1. If the main burners fail to light, or the blower fails to
start, shut down gas heating section and call your dealer for
service.
3. Turn ON the electrical power supply to the unit.
4. Set system switch to COOL.
2. Never attempt to manually light the main burners on unit
with a match, lighter, or any other flame. If the electric
sparking device fails to light the main burners, refer to the
following shutdown procedures, then call your dealer as
soon as possible.
5. Set the temperature selector on room thermostat slightly be-
low the room temperature to start unit.
To shut off unit electric cooling:
Refer to Fig. 8 while proceeding with the following steps.
1. Set the temperature selector on room thermostat to highest
temperature setting and set system SWITCH to OFF.
2. Close the external manual shutoff valve, if not already
closed.
3. Turn off the electrical power supply to the unit.
NOTE: Heat Pump heating mode procedure is similar to electric
cooling mode except thermostat mode is HEAT and thermostat
must operate on first stage heating above the balance point that has
been determined by the Dealer.
OPERATING YOUR UNIT
The operation of your unit is controlled by the indoor temperature
control (thermostat). You simply adjust the thermostat and it
maintains the indoor temperature at the level you select. Most
thermostats of heating and cooling systems have 3 controls: a
temperature control selector, a FAN control, and a SYSTEM or
MODE control. Refer to your thermostat owner’s manual for more
information.
Flue Hood
Burners
Gas Valve
A09043
To better protect your investment and to eliminate unnecessary
service calls, familiarize yourself with the following facts:
Fig. 4 -- Gas Heating/Electric Cooling Unit with Access Panel
Removed
1. During heat pump heating, increasing the thermostat setting
more than 2_F (1.1_C) may cause the supplemental gas heat
to be turned on for a short period of time to satisfy the
thermostat. Needless use of the supplementary heat reduces
potential energy savings.
To shut off unit gas heat:
WARNING
EXPLOSION,
!
2. Ice or frost tends to form on the coil during winter heating
operation. Your heat pump is designed to automatically melt
the ice. When in this defrost cycle, it is normal for steam
or fog to rise from the outdoor unit. Do not be alarmed!
FIRE,
HAZARD
ELECTRICAL
SHOCK
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Cooling Mode
With the SYSTEM 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.
Do not turn off the electrical power to unit without first
turning off the gas supply.
NOTE: If the unit is being shut down because of a malfunction,
call your dealer as soon as possible.
Heat Pump Heating Mode
Should overheating occur or the gas supply fail to shut off, shut
off the external manual gas valve to the unit before shutting off
the electrical supply. Do not use this unit if any part has been under
water. Immediately call a qualified service technician to inspect the
unit and to replace any part of the control system and any gas
control which has been under water.
With the SYSTEM or MODE control of your indoor thermostat set
to HEAT, your unit will run in heat pump heating mode until room
temperature is raised to the level you have selected. Of course, your
system will run for longer periods to maintain a comfortable
environment on cooler days and nights than on moderate ones.
Gas Heat Mode
Refer to Fig. 6 while proceeding with the following steps.
Your heat pump is your primary heating source. Your system is
also equipped with a supplemental gas heating source. On cold
days and nights, your system will automatically turn on the
supplemental heat in order to maintain the level of comfort you
have selected.
1. Set the temperature selector on room thermostat to lowest
temperature setting and set system SWITCH to OFF.
2. Close the external manual shutoff valve.
3. Turn off the electrical power supply to the unit.
4. Remove the control access panel. (See Fig. 3.)
When your heat pump needs additional heat to keep you
comfortable, your thermostat will turn on the supplemental gas
heat.
4
MAIN
ON
55
OFF
STEP 1
STEP 2
STEP 3
STEP 5
STEP 4
STEP 6
STEP 7
MAIN
ON
72
OFF
STEP 8
STEP 9
STEP 10
A07662
Fig. 5 -- To Start Unit Gas Heat
5
MAIN
ON
55
OFF
STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
A07663
Fig. 6 -- To Shut Off Unit Gas Heat
MAIN
ON
72
90
OFF
STEP 4 & 5
STEP 2
STEP 1
STEP 3
A09194
Fig. 7 -- To Start Unit Electric Cooling
6
MAIN
ON
90
OFF
STEP 1
STEP 2
STEP 3
A07797
Fig. 8 -- To Shut Off Unit Electric Cooling
Defrost Mode
!
When your heat pump is providing heat to your home or office and
the outdoor temperature drops below 45°F (7.2°C), moisture may
begin to freeze on the surface of the coil. If allowed to build up,
this ice would impede airflow across the coil and reduce the
amount of heat absorbed from the outside air. So, to maintain
energy--efficient operation, your heat pump has an automatic
defrost mode.
The defrost mode starts at a preset time interval of 60 minutes,
although, it may be reset to 30, 90 or 120 minutes. Defrost will
start at the preset time only if the ice is sufficient to interfere with
normal heating operation.
WARNING
FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CUT HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
1. Turn off gas supply first, then all electrical power to your
unit and install lock--out tag before servicing or per-
forming maintenance.
2. 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. Wear safety glasses, gloves, and appropriate
protective clothing.
After the ice is melted from the coil, or after a maximum of 10
minutes in defrost mode, the unit automatically switches back to
normal heating operation.
Do not be alarmed if steam or fog appears at the outdoor unit
during defrost mode. Water vapor from the melting ice may
condense into a mist in the cold outside air.
During certain weather conditions such as heavy snow and freezing
rain it is not uncommon for ice to build up on the unit grille. This
is normal for these weather conditions. Do not attempt to remove
the ice from the unit grille. This condition will not affect the proper
function of the unit and will clear within a few days.
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 excessive stress on the blower motor and can cause the
motor to overheat and shut down.
Emergency Heat Mode
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
applications, 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 replaced.
The other typical application is an accessory filter rack installed
inside the unit itself. The following information is given to assist in
changing filters used in these internal filter racks.
Table 1 indicates the correct indoor filter size for your unit. Refer
to Fig. 3 to access filters installed in the accessory filter rack. If
using an Accessory Filter Rack, refer to the Installation Instructions
provided with it for correct filter sizes and quantities.
Table 1 – Indoor Air Filter Data
If you should have problems with the heat pump portion of your
system, this mode allows your supplemental gas heating source to
keep your home or office warm until your heat pump can be
serviced.
MAINTENANCE AND SERVICE
This section discusses maintenance that should be performed on
your system. Most maintenance should be performed by your
dealer. 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.
For your safety, keep the unit area clear and free of combustible
materials, gasoline, and other flammable liquids and vapors.
Unit Size
24040
Filter Size in. (mm)
20x20x1 (508x508x25)
20x24x1 (508x610x25)
24x30x1 (610x762x25)
24x36x1 (610x914x25)
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.
[1067 mm] clearance) and the duct side (12 in. [305 mm]
minimum clearance.
24060 and 30
36 --- 42
48 --- 60
To replace or inspect filters in accessory filter rack (See Fig. 3):
1. Remove the filter access panel using a 5/16--in. nut driver.
Maintenance and Care for the Equipment Owner
Before proceeding with those things you might want to maintain
yourself, please carefully consider the following:
2. Remove the filter(s) by pulling it out of the unit. If the
filter(s) is dirty, clean or replace with a new one.
7
When installing the new filter(s), note the direction of the airflow
arrows on the filter frame, which should be pointing at the indoor
coil.
!
CAUTION
3. Reinstall filter access panel ensuring opening is air and
watertight.
UNIT OPERATION HAZARD
Failure to follow this caution may result in property
damage.
If you have difficulty locating your air filter(s) or have questions
concerning proper filter maintenance, contact your dealer for
instructions. When replacing filters, always use the same size and
type of filter that was supplied originally by the installer.
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 and blower motor and/or
compressor damage.
Replacing or inspecting filters in units with
economizers
Small Chassis (See Fig. 9)
1. Remove return air duct cover at rear of unit using a 5/16--in.
nut driver.
2. Remove the filter(s) by pulling it out and through the unit
duct opening. If filter is dirty, replace both filters with new
ones.
When installing the new filters, note the direction of the airflow
arrows on the filter frame, which should be pointing at the indoor
coil.
3. Reinstall duct cover ensuring opening is air and watertight.
Table 2 – Indoor Air Filter Data with Economizer
48EZ Unit Size
Filter Size in. (mm)
2 each 20 x 12 x 1
30-040/060
(508 x 305 x 25)
2 each 20 x 12 x 1
36-060/090
42-060/090
(508 x 305 x 25)
RETURN
1 each 24 x 14 x 1 (610 x 356 x 25),
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 14 x 1 (610 x 356 x 25),
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 16 x 1 (610 x 406 x 25),
24 x 18 x 1 (610 x 457 x 25)
DUCT COVER
(Remove for
filter access)
SMALL CHASSIS
48-090/115/130
60-090/115/130*
*Units with bent indoor coil.
A10063
Fig. 9 -- Small Chassis Filter Access
48VT Unit Size
Filter Size in. (mm)
2 each 20 x 12 x 1
(508 x 305 x 25 mm)
30-040/060
1 each 24 x 14 x 1 (610 x 406 x 25),
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 14 x 1 (610 x 356 x 25),
24 x 16 x 1 (610 x 406 x 25)
1 each 24 x 16 x 1 (610 x 406 x 25),
24 x 18 x 1 (610 x 457 x 25)
1 each 24 x 16 x 1 (610 x 406 x 25),
24 x 18 x 1 (610 x 457 x 25)
36-060/090
42-060/090
48-090/115/130*
60-090/115/130*
*Units with bent indoor coil.
Large Chassis (See Fig. 10)
1. Remove filter access door using a 5/16--in. nut driver.
FILTER
ACCESS
PANEL
2. Remove the filter(s) by pulling it out and through the unit
filter access door. If filter is dirty, replace both filters with
new ones.
Units with bent indoor coils, install 24 x 18 x 1 (610 x 457 x 25
mm) filter first and then install 24 x 16 x 1 (610 x 406 x 25) filter.
When installing the new filters, note the direction of the airflow
arrows on the filter frame, which should be pointing at the indoor
coil.
LARGE CHASSIS
A10062
Fig. 10 -- Large Chassis Filter Access
3. Reinstall filter access door ensuring opening is air and
watertight.
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
personnel. Contact your dealer for the required annual
maintenance.
8
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
dealer.
WARNING
FIRE, EXPLOSION HAZARD
Compressor
Failure to follow this warning could result in personal
injury, death and/or property damage.
All compressors are factory shipped with a normal charge of the
correct type and quantity of refrigeration grade oil. A compressor
should rarely require additional oil.
If your unit makes an especially loud noise when the main
burners are ignited, shut down the heating section and call
your dealer.
Condenser (Outdoor) Fan
!
WARNING
!
CAUTION
PERSONAL INJURY AND UNIT DAMAGE
HAZARD
BURN HAZARD
Failure to follow this caution may result in personal injury.
Failure to follow this warning could result in personal
injury, death or property damage.
Components in heating section may be hot after unit has
been started up. When observing flame, be careful not to get
close to or touch heating components.
Do not insert sticks, screwdrivers, or any other objects into
revolving fan blades.
The fan must be kept free of all obstructions to ensure proper
cooling. Contact your dealer for any required service.
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:
Electrical Controls and Wiring
Electrical controls are difficult to check without proper
instrumentation. If there are any discrepancies in the operating
cycle, contact your local dealer and request service.
1. Inspection of all flue product passages--including the burn-
ers, heat exchanger, and flue collector box, Mare sure the
burner flames are blue in color and in proper adjustment.
Refer to Fig. 11 for burner flame.
2. Inspection of all combustion--and ventilation--air passages
and openings.
Refrigerant Circuit
The refrigerant circuit is difficult to check for leaks without the
proper equipment. If inadequate cooling is suspected, contact your
local dealer for service.
3. Close inspection of all gas pipes leading to and inside of
your unit.
!
WARNING
4. Inspection and, if required, cleaning of the outdoor and
indoor coils.
EXPLOSION,
HAZARD
BURN AND ENVIRONMENTAL
5. Inspection and, if required, cleaning of the indoor coil con-
densate drain pan.
Failure to follow this warning could result in personal
injury, death or property damage.
6. Inspection and cleaning of blower wheel housing and
motor.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal. Use
all service ports and open all flow--control devices,
including solenoid valves.
7. Inspection of all supply--air and return--air ducts for leaks,
obstructions, and insulation integrity. Any problems found
should be resolved at this time.
8. Inspection of the unit base to ensure that no cracks, gaps,
etc., exist which may cause a hazardous condition.
Unit Panels
9. Inspection of the unit casing for signs of deterioration.
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
airflow pattern.
10. Inspection of all electrical wiring and components to assure
proper connection.
11. Inspection for leaks in the refrigerant circuit. Pressure and
temperature check to determine appropriate refrigerant
charge.
Combustion Area and Vent System
For proper and safe operation, the furnace needs air for combustion
and ventilation. The air openings, on the furnace, the air openings
to the area in which the furnace is installed, and the spacing around
the furnace must not be blocked or obstructed.
12. 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.
The combustion area and vent system should be inspected visually
before each heating season. The normal accumulation of dirt, soot,
rust, and scale can result in loss of efficiency and improper
performance if allowed to build up. This inspection should be done
by a trained service person.
Warranty Certificate
Your unit has a limited warranty. Be sure to read the warranty
carefully to determine the coverage for your unit.
9
SYSTEM switch or MODE control is in the COOL or HEAT and
not OFF.
Before you call for service...
...check for several easily--solved problems.
If insufficient heating or cooling is suspected:
(
) 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.
(
) 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:
In Case of Trouble
If you perform the steps above and unit performance is still
unsatisfactory, shut off the unit and call your dealer.
(
) Check to be sure that your thermostat temperature selector is
set below the indoor temperature during the cooling season or
above the indoor temperature during heating season. Be sure the
BURNER FLAME
BURNER
MANIFOLD
C99021
Fig. 11 -- Monoport Burner
C a t a l o g N o : O M 4 8 E Z --- V T --- 0 4
Copyright 2010 Carrier Corp. S 7310 W. Morris St. S Indianapolis, IN 46231
Edition Date: 04/10
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
R e p l a ce s: OM 4 8 E Z --- VT --- 0 3
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