Carrier 50NQ Dimensions and installation guide

50NQ
Single-Package Heat Pumps
HEATING A COOLING
Installation, Start-Up and Service Instructions
CONTENTS
Page
SAFETY CONSIDERATION. 1
INSTALLATION.1-7
Step 1—Moving and Setting Unit in Place.4
• ROOFTOP INSTALLATION
• GROUND-LEVEL INSTALLATION
• CLEARANCES
Step 2— C ondensate Disposal. 4
Step 3—Duct Connections.6
Step 4—Electrical Connections.6
• HIGH-VOLTAGE CONNECTIONS
• PROCEDURES FOR 208V
• CONTROL VOLTAGE CONNECTIONS
• HEAT ANTICIPATOR SETTING
• CIRCUIT BREAKER
PREPARING UNIT FOR START-UP.7
START-UP AND ADJUSTMENTS.9
CARE AND MAINTENANCE.10
NOTE TO INSTALLER: Leave these instructions and the
User’s Manual with the equipment user after installation.
INTRODUCTION
Model 50NQ Packaged Heat Pump Units are fully self-
contained, heating/cooling units designed for outdoor instal¬
lation. These units may be installed either on a rooftop or
ground-level slab. For rooftop downflow applications, an
accessory roof-mounting curb may be used.
SAFETY CONSIDERATIONS
Installing and servicing air conditioning equipment can be
hazardous due to system pressure and electrical compo¬
nents. Only trained and qualified service personnel should
install or service air conditioning equipment.
Untrained personnel can perform basic maintenance func¬
tions such as cleaning coils and filters and replacing filters.
All other operations should be performed by trained service
personnel. When working on air conditioning equipmei^,
observe precautions in the literature and on tags and labels
attached to unit.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations. Have
fire extinguisher available.
Recognize safety information: This is the safety-alert sym¬
bol A, when you see this symbol on the unit and in instruc¬
tions or manuals, be alert to the potential for personal
injury.
Understand the signal word—DANGER, WARNING or
CAUTION. These words are used with the safety-alert sym¬
bol. DANGER identifies the most serious hazards which
will result in severe personal injury or death. WARNING,
on the other hand could result in personal injury or death.
CAUTION is used to identify unsafe practices, which would
Fig. 1—Model 50NQ
result in minor personal injury or product and property
damage.
1. This installation must conform with all applicable local
and national codes.
2. The power supply (volts, hertz, and phase) must corre¬
spond to that specified on unit rating plate. (See Fig. 4
for location.)
3. The electrical supply provided by the utility must be
sufficient to handle load imposed by this unit.
4. Refer to the dimensional drawings (Figs. 2 and 3) for
locations of electrical inlets, condensate drain, duct
connections, and required clearances before setting
unit in place.
5. Unit designed for outdoor installation on wood flooring
or on class A, B, or C roof covering materials.
GENERAL
Model 50NQ Packaged Heat Pump has been designed and
tested in accordance with ARI Standard 240, 270 and U.L.
Standard 559.
These units are factory-charged with R-22 refrigerant.
Installation is simple: connect air ducts, high- and low-
voltage wiring, condensate drain, and install a field-supplied
air filter.
All units can be connected into existing duct systems that
are properly sized and designed to handle an airflow of 375
to 450 Cfm per each 12,000 Btuh of rated cooling capacity.
Refer to pre-sale literature for detailed air delivery capacity.
NOTE: When installing any accessory item, see the manu¬
facturer’s Installation Instructions packaged with the
accessory. The Qualified Agency must use factory author¬
ized kits or accessories when modifying this unit.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 101 Catalog No 565-116 Printed in U.S.A Form 50NQ-1SI Pg 1 7-89 Replaces: New
Book
1
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Drawing—Small
Cabinet

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Fig.
3—Dimensional
Drawing—Large
Cabinet

DOOR
A89215
Fig. 4—Rating Plate Location
Step 1 — Moving and Setting Unit in Place
A CAUTION
Use spreader bars and crate top when rigging the unit
to be lifted. Model 50NQ must be rigged for lifting as
shown in Fig. 5. Use extreme caution to prevent dam¬
age when moving the unit. Unit must remain in an
upright position during all rigging and moving opera¬
tions. The unit must be level for proper condensate
drainage; therefore, the ground-level pad or accessory
roof-mounting curb must be level before setting the
unit in place. When a field-fabricated support is used,
ensure that the support is level and properly supports
the unit.
ROOFTOP INSTALLATION
A CAUTION
When installing the unit on a rooftop, be sure that the
roof will support the additional weight. Refer to Figs. 2
and 3 for total weight and corner weight information.
For downflow applications, an accessory roof-mounting *
curb may be installed on, and flashed into the roof before
unit installation. The instructions for installing the acces¬
sory curb are packaged with the curb.
For end-discharge applications place the unit on a level base
that provides proper support. Refer to Fig. 7 for location of
additional supports/sleepers. On flat roofs, be sure that the
unit is located at least 4 ins. above the highest expected
water level on the roof to prevent flooding.
GROUND-LEVEL INSTALLATION
Place the unit on a solid, level, concrete pad that extends
approximately 2 ins. beyond the casing on all four sides of
the unit. Do not secure the unit to the pad except when
required by local codes. Ensure pad does not obstruct coil
drainage holes in bottom of unit. (Holes drain water during
cooling and defrost cycles.) In areas where prolonged sub¬
freezing temperatures or snowfall occur, increase clearance
to 12-18 ins. by constructing an angle-iron frame to support
Fig. 5—Suggested Rigging
the unit. The frame should be designed so as not to block
the drainage holes. See Fig. 8 and Table 1 for recommended
frame construction. Extend a 24-in. gravel apron around
pad for condensate and defrost water drainage.
CLEARANCES
The required minimum operating and service clearances are
shown in Figs. 2 and 3. Adequate condenser air must be
provided.
A CAUTION
Do not restrict condenser airflow. An air restriction at
either the outdoor-air inlet (the entire surface of the out¬
door coil) or the fan discharge can be detrimental to
compressor life.
The condenser fan discharges through the top of the unit.
Ensure that the fan discharge does not recirculate to the
condenser coil. Do not locate the unit in either a corner or
under a complete overhead obstruction. The minimum clear¬
ance under a partial overhang (such as a normal house roof
overhang) is 48 ins. above unit top. The maximum horizon¬
tal extension of a partial overhang must not exceed 48 ins.
Do not locate the unit where water, ice, or snow from an
overhang or roof will damage or flood the unit by falling on
the top. Do not locate the unit where grass, shrubs, or other
plants will interfere with the airflow either into or out of the
unit. Do not install the unit on carpeting, tile, or other com¬
bustible material other than wood flooring. Heat pump may
be installed on wood flooring or on Class A, B, or C roof cov¬
ering materials.
Step 2—Condensate Disposal
NOTE: Ensure that condensate-water disposal methods
comply with local codes, restrictions, and practices.
Model 50NQ disposes of condensate water through a 3/4-in.
NPT drain fitting. See Figs. 2 and 3 for location.
Install a 3-in. trap at the drain fitting to ensure proper
drainage. See Fig. 6. Make sure that the outlet of the trap is
at least 1 in. lower than the unit drain pan connection to
prevent the pan from overflowing. Prime the trap with
water.
If the installation requires draining the condensate water
away from the unit, connect a drain tube using a minimum
of 7/8-in. OD copper tubing, 3/4-in. galvanized pipe, or
3/4-in. plastic pipe. Do not undersize the tube. Pitch the
4

1" MIN.
2" MIN.
A88130
♦ These embossments are located on Large Cabinet Units (048-060 size only.)
Fig. 7—Additional Support/Sleeper
Location
©E
©E
©^
® E
© ■ n
-=nk
1-1/2" (38mm)
1-1-
1/2" (38mm)
MATERIAL:
ANGLE IRON - 1-1/4" (31 8mm) TO 1-1/2" (38mm) COMM'L STD
WELD FRAME TOGETHER
PAINT WITH ZINC-RICH PAINT (RUSTPROOF)
Table 1—Mounting Frame
Dimensions
Item No.
Large Cabinet
Length
Small Cabinet
Length
Quantity
A
50 in
(1269mm)
40-3/8 in
(1024mm)
—
B
60-1/2 in
(1535mm)
47 in
(1193mm)
__
C
30-1/4 in
(766mm)
23-1/2 in
(597mm)
—
1
12 in (305mm)
to
24 in (610mm)
12 in (305mm)
to
24 in (610mm)
4
2
60 in
(1523mm)
46-1/2 in
(1181mm)
2
3
49-1/2 in
(1257mm)
39-7/8 in
(1012mm)
2
4
49-1/2 in
(1257mm)
39-7/8 in
(1012mm)
1
5 16 in
(406mm)
16 in
(406mm)
8
Fig. 8—Mounting Frame
5

drain tube downward at a slope of at least 1 in. in every 10
ft of horizontal run. Be sure to check the drain tube for
leaks.
Condensate water can be drained directly onto the roof in
rooftop installations (where permitted) or onto a gravel
apron in ground-level installations. When using a gravel
apron, make sure it slopes away from the unit.
Step 3— Duct Connections
Model 50NQ has duct flanges on the supply and return air
openings on the side and bottom of the unit except on sizes
048 and 060. 048 and 060 sizes do not have flanges on side
discharge openings. See Figs. 2 and 3 for connection sizes
and locations.
NOTE: The design and installation of the duct system must
be in accordance with the standards of the National Fire
Protection Association for installation of nonresidence-type
air conditioning and ventilating systems, NFPA No. 90A or
residence type, NFPA No. 90B, and/or local codes and
ordinances.
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Remove appropriate panels from unit to obtain either
horizontal or down discharge. If models 018 through
042 are installed in horizontal discharge applications,
remove side duct covers, save screws, and install the
covers on bottom duct openings. To install duct covers
on bottom duct openings, remove one flange which
interferes with heater mounting plate. For models 048
through 060 remove either side or bottom duct covers
as needed and discard.
2. Select and size ductwork, supply-air registers, and
return-air grilles according to ASHRAE recom¬
mendations. Refer to Tables 2 & 3 for static pressure
capability.
A CAUTION
When the duct-system fastening holes are being drilled
into side of unit instead of the unit duct flanges, use
extreme care to avoid puncturing the coil or coil tubes.
See Fig. 9.
3. Use flexible transition between rigid ductwork and unit
to prevent transmission of vibration. The transition
may be screwed or bolted to duct flanges. Use suitable
gaskets to ensure weather and airtight seal.
4. Install external, field-supplied air filter(s) in return-air*
ductwork where it is easily accessible for service. Rec¬
ommended filter sizes are shown in Table 4.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid
abrupt duct size increases or decreases.
6. Adequately insulate and weatherproof all ductwork
located outdoors. Insulate ducts passing through
unconditioned space and use vapor barrier in accor¬
dance with latest issue of SMACNA and ACC A mini¬
mum installation standards for heating and air condi¬
tioning systems. Secure all ducts to building structure.
7. Flash, weatherproof, and vibration-isolate all openings
in building structure in accordance with local codes and
good building practices.
8. For Canadian Installations Only—An L-shaped
exhaust duct fabricated of sheet metal or a material
rated 94-5V shall be used in the case of downflow
applications.
Step 4—Electricial Connections
A WARNING
The unit cabinet must have an uninterrupted, unbro¬
ken, electrical ground to minimize the possibility of per¬
sonal injury if an electrical fault should occur. This
ground may consist of electrical wire connected to the
unit ground lug in the control compartment, or conduit
approved for electrical ground when installed in accor¬
dance with the National Electrical Code ANSI/NFPA-
70 (in Canada, Canadian Electrical Code CSA C22.1)
and local electrical codes.
A CAUTION
A failure to follow these precautions could result in
damage to the unit being installed:
1. Make all electrical connections in accordance with the
latest National Electrical Code, ANSI/NFPA-70 and
local electrical codes governing such wiring. In Canada,
all electrical connections must be in accordance with
CSA standard C22.1 Canadian Electrical Code part 1
and applicable local codes. Refer to Unit Wiring
Diagram.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3.
4.
5.
Ensure that high-voltage power to unit is within oper¬
ating voltage range indicated on unit rating plate (Fig.
4). On 3-phase units, ensure that phases are voltage
and current balanced. Consult local power company for
correction of improper voltage and/or phase balance.
Insulate low-voltage wires for highest voltage con¬
tained within conduit when low-voltage control wires
are run in same conduit as high-voltage wires.
Do not damage internal components when drilling
through any panel to mount electrical hardware, con¬
duit, etc.
CAUTION: DO NOT DRILL
OR SCREW IN SHADED AREA
SUPPLY
5 0"1
RETURN
INLET/OUTLET PANEL
Cabinet Size
A
Small Cabinet
20-1/2"
018-042
Large Cabinet
21-1/4"
048-060
Fig. 9—Location of Coil Area-
Not to be Drilled
6

HIGH-VOLTAGE CONNECTIONS
The unit must have a separate electrical service with a field-
supplied, waterproof disconnect switch mounted at, or
within sight from the unit. Refer to the unit rating plate
(Fig. 4) for maximum over-current device size and minimum
circuit amps (ampacity) for wire sizing.
The field-supplied disconnect switch box may be mounted
on the unit over the high-voltage inlet hole in the control
corner panel. See Figs. 2 and 3.
Proceed as follows to complete the high-voltage connections
to the unit:
1. Connect ground lead to chassis ground connection
when using separate ground wire.
2. Run high voltage leads into unit through inlet hole in
control box post, and to contactor through the hole in
the bottom of control box. The high voltage leads
should remain in conduit until entering control box and
a watertight termination should be made at bottom of
control box.
SPECIAL PROCEDURES FOR 208-V OPERATION
A WARNING
Make sure that the power supply to the unit is switched
OFF before making any wiring changes. Electrical
shock can cause personal injury or death.
For operation of 208 volts, disconnect the yellow
transformer-primary lead from the contactor. See the unit
wiring label. Remove the tape and cover from the terminal
on the end of the blue transformer-primary lead. Save the
cover. Connect the blue lead to the contactor terminal from
which the yellow lead was disconnected.
Using the cover removed from the blue lead, insulate the
loose terminal on the yellow lead. Wrap the cover with elec¬
trical tape so that the metal terminal cannot be shorted.
Indoor blower motor speed taps should be changed for 208V
operation on 208/230v rated units. Interchange motor lead
at blower motor. See “Start-up and Adjustments” section
(page 9) and unit wiring label.
CONTROL VOLTAGE CONNECTIONS
Locate the room thermostat on an inside wall in the space to
be conditioned where it will not be subjected to either a cool¬
ing or heating source or direct exposure to sunlight. Mount
the thermostat 4 to 5 ft above the floor.
Use No. 18 AWG color-coded, insulated (35 C minimum)
wires to make the control voltage connections between the
thermostat and the unit. If the thermostat is located more
than 100 ft from the unit (as measured along the control
voltage wires), use No. 16 AWG color-coded, insulated (35 C
minimum) wires.
A grommeted control voltage inlet hole is located in the
panel adjacent to the control access panel. See Figs. 2 and 3.
Run the low-voltage leads from the thermostat, through the
inlet hole, and to the control voltage terminals. Connect the
thermostat leads to the terminals as shown in Fig. 10.
HEAT ANTICIPATOR SETTING
Factory thermostats have fixed heat anticipator settings.
No adjustment is required.
CIRCUIT BREAKER
Unit has manual reset circuit breaker which is located in the
low-voltage wiring box adjacent to low-voltage terminal
board. If unit fails to operate, first check breaker for tripped
position. If breaker is tripped, re-set and try to start unit. If
breaker continues to trip there is a problem in the low-
voltage electrical circuit (electrical short, ground, or trans¬
former overload). Correct the condition and check for nor¬
mal unit operation.
PREPARING UNIT FOR START-UP
A WARNING
Failure to observe the following warnings could result
in serious personal injury:
1. Follow recognized safety practices and wear protec¬
tive goggles when checking or servicing refrigerant
system.
2. Do not operate compressor or provide any electric
power to unit unless compressor terminal cover is in
place and secured.
3. Do not remove compressor terminal cover until all
electrical sources have been disconnected.
4. Relieve all pressure from system before touching or
disturbing anything inside compressor terminal box
if refrigerant leak is suspected around terminals.
5. Never attempt to repair soldered connection while
refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To
remove a component, wear protective goggles and
proceed as follows:
a. Relieve all pressure from system.
b. Cut component connecting tubing with tubing
cutter and remove component from unit.
c. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
PRESTARTUP PROCEDURES
Proceed as follows to inspect and prepare the unit for initial
startup:
1. Remove all access panels.
2. Read and follow instructions on all WARNING, CAU¬
TION, and INFORMATION labels attached to, or
shipped with, unit.
3. Make the following inspections:
a. Inspect for shipping and handling damages such as
broken lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections
and on unit base. Detecting oil generally indicates a
refrigerant leak. Leak-test all refrigerant tubing
connections using electronic leak detector, halide
torch, or liquid-soap solution. If refrigerant leak
is detected, see “Refrigerant Leaks” section on
page 9.
c. Inspect all field- and factory-wiring connections. Be
sure that connections are completed and tight.
d. Inspect coil fins. If damaged during shipping and
handling, carefully straighten fins with a fin comb.
4. Verify the following conditions:
a. Make sure that outdoor fan blade is correctly posi¬
tioned in fan orifice. Blades should clear fan motor
by no more than 1/4 in. The fan blade hub should be
flush with end of motor shaft.
b. Make sure that air filter(s) is in place.
c. Make sure that condensate drain pan and trap are
filled with water to ensure proper drainage.
7

THERMOSTAT
& SUBBASE
(SEE BELOW)
0 -
&
&
0 -
@
II}-
0 -
UNIT
CONTROL WIRING
TERMINAL BOARD
05 >
-<0
~(l)
• 0 )
-<t>
A88057
COOLING AND ONE-STAGE HEATING
(without Electric Heater)
THERMOSTAT UNIT
8 SUBBASE CONTROL WIRING
TERMINAL BOARD
ODT — Outdoor Thermostat
HR — Heater Relay
COOLING AND TWO-STAGE HEATING
(Unit equipped with Electric Heater, Supplemental
Heat, One Outdoor Thermostat)
THERMOSTAT UNIT
a SUBBASE CONTROL WIRING
TERMINAL BOARD
COOLING AND TWO-STAGE HEATING
(Unit equipped with Electric Heater, Supplemental
Heat, No Outdoor Thermostats)
THERMOSTAT UNIT
a SUBBASE CONTROL WIRING
TERMINAL BOARD
SHR — Supplemental Heat Relay
HR — Heater Relay
ODT — Outdoor Thermostat
COOLING AND TWO-STAGE HEATING
(Unit equipped with Electric Heater, Supplemental
Heat Relay, Two Outdoor Thermostats)
Fig. 10—Control Connections
8

d. Make sure that all tools and miscellaneous loose
parts have been removed.
Unit is now ready for initial startup.
REFRIGERANT LEAKS
Proceed as follows to repair a refrigerant leak and to charge
the unit:
1. Locate leak and ensure that refrigerant system pres¬
sure has been relieved.
2. Repair leak following accepted practices.
NOTE: Install a filter-drier whenever the system has been
opened for repair.
3. Add a small charge of R-22 refrigerant vapor to system
and leak-test unit.
4. Evacuate refrigerant system if additional leaks are not
found.
5. Charge unit with R-22 refrigerant, using a volumetric-
charging cylinder or accurate scale. Refer to unit rating
plate for required charge. Be sure to add extra refriger¬
ant to compensate for internal volume of filter-drier.
START-UP AND ADJUSTMENTS
A CAUTION
Complete the required procedures given in “Preparing
Unit for Start-up,” page 7, before starting the unit.
Do not jumper any safety devices when operating the
unit.
Do not operate unit in the cooling mode when the out¬
door temperature is below 55 F (unless accessory low-
temperature kit is installed).
Do not operate unit in heating mode when outdoor tem¬
perature is above 60 F.
Do not rapid-cycle the compressor. Allow 5 minutes
between “on” cycles to prevent compressor damage.
The unit compressor is equipped with a crankcase heater. It
is recommended that heater be energized a minimum of 24
hours before starting unit. To energize heater only, set ther¬
mostat at OFF position; turn on unit main power at discon¬
nect switch.
TO START UNIT—Check that main power is on and that
compressor crankcase heater has been energized for at least
24 hours.
1. Check that heater main power is on as applicable.
2. Set selector switch at OFF.
3. Set fan switch as desired (FAN) (AUTO.).
4. Set thermostat dial at the desired temperature.
5. Set selector switch at HEAT or COOL. Check system
refrigerant charge as described in “Checking Charge”
section below.
CHECKING CHARGE—Factory Charge is shown on unit
rating plate (See Fig. 4).
A CAUTION
Compressor damage may occur if system is over¬
charged.
Adjust charge in cooling mode by following procedure
shown on the “superheat charging tables” located on unit.
Check charge in heating by following procedure shown on
“heating check chart” located on unit.
9

INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
A CAUTION
For proper operation, the recommended airflow is 375
to 450 CFM for each 12,000 BTUH of rated cooling
capacity. Minimum airflows may be different if supple¬
mental electric heaters are installed. See Table 5.
These units have direct-drive blower motors. Blower motors
are factory-connected to deliver the proper heating and cool¬
ing airflows at normal external static pressures.
Tables 2 and 3 show both heating and cooling airflows at
various external static pressures. Refer to these tables to
determine the airflow for the system being installed. See
Table 4 for the rated heating and cooling airflows.
NOTE: Be sure that all supply- and return-air grilles are
open, free from obstructions, and adjusted properly.
A WARNING
Disconnect electrical power to the unit before changing
blower speed. Electrical shock can cause personal
injury or death.
The heating and/or cooling airflow of 208/230-V direct-drive
blower motors can be changed by changing the lead connec¬
tions at the blower motor. The motor leads Eire color-coded
as follows:
black — high speed
blue = medium speed
red = low speed
UNIT CONTROLS
All compressors have the following internal-protection
controls:
1. High-pressure Relief Valve —This valve opens when the
pressure differential between the low and high side
becomes excessive.
2. Compressor Overload —This overload interrupts power
to the compressor when either the current or internal
temperature become excessive, and automatically
resets when the internal temperature drops to a safe
level. This overload may require up to 60 minutes (or
longer) to reset; therefore, if the internal overload is
suspected of being open, disconnect the electrical
power to the unit and check the circuit through the
overload with an ohmmeter or continuity tester.
SEQUENCE OF OPERATION
COOLING—On a call for cooling, thermostat makes circuit
R-O, R-Y and R-G. When room temperature rises to within 2
degrees of control setting of thermostat, circuit R-0 makes,
energizing reversing valve solenoid (RVS). Unit is now in
standby condition for cooling. As room temperature rises,
the second-stage bulb makes, allowing a circuit (R-Y)
through low-pressure switch (LPS) to contactor (C), starting
compressor (COMP) and outdoor fan motor (OFM). Circuit
R-G energizes indoor fan relay (IFR) starting indoor fan
motor (IFM).
When thermostat is satisfied, contacts open de-energizing
contactor. Indoor fan relay, compressor and motor stop.
HEATING—On a call for heat, thermostat makes circuits
R-Y and R-G. Circuit R-Y is completed, allowing circuit
through low-pressure switch (LPS) to contactor (C), starting
compressor (COMP) and outdoor fan motor (OFM). Circuit
R-G also is completed, energizing indoor fan relay (IFR) and
starting indoor fan motor (IFM).
Should room temperature continue to fall, circuit R-W is
made through second-stage thermostat bulb. If optional
electric heat package is used, a sequencer is energized bring¬
ing on first bank of supplemental electric heat. When ther¬
mostat is satisfied, contacts open, de-energizing contactor
and sequencer. Motors and heaters de-energize.
DEFROST—Defrost board (DB) is a time/temperature con¬
trol which includes a field-selectable time period between
check if defrost is necessary (30, 50 and 90 minutes). Elec¬
tronic timer and defrost cycle start only when contactor is
energized and defrost thermostat (DFT) is closed.
Defrost mode is identical to cooling mode except outdoor
fan motor stops and a bank of optional electric heat turns
on to warm air supplying the conditioned space.
CARE AND MAINTENANCE
To ensure continuing high performance, and to minimize the
possibility of premature equipment failure, periodic mainte¬
nance must be performed on this equipment. This combina¬
tion heating/cooling unit should be inspected at least once
each year by a qualified service person.
NOTE TO EQUIPMENT OWNER: Consult your local Dealer
about the availability of a maintenance contract.
A WARNING
The ability to properly maintain this equipment
requires certain expertise, mechanical skills, tools, and
equipment. If you do not possess these, do not attempt
to perform any maintenance on this equipment other
than those procedures recommended in the Users Man¬
ual. A FAILURE TO HEED THIS WARNING
COULD RESULT IN SERIOUS PERSONAL
INJURY AND POSSIBLE DAMAGE TO THIS
EQUIPMENT.
The minimum maintenance requirements for this equipment
are as follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary.
2. Inspect cooling coil, drain pan, and condensate drain
each cooling season for cleanliness. Clean when
necessary.
3. Inspect blower motor and wheel for cleanliness each
heating and cooling season. Clean when necessary.
4. Check electrical connections for tightness on controls
for proper operation each heating and cooling season.
Service when necessary.
A WARNING
A failure to follow these warnings could result in seri¬
ous personal injury.
AIR FILTER
A CAUTION
Never operate the unit without a suitable air filter in
the return-air duct system. Always replace the filter
with the same dimensional size and type as originally
installed. See Table 4 for recommended filter sizes.
Inspect air filter(s) at least once each month and replace
(disposable-type) or clean (cleanable-type) at least twice dur¬
ing each heating and cooling season or whenever the filter(s)
becomes clogged with dust and lint.
10