Carrier 48HX030-060 Dimensions and installation guide

Installation, Start-Up and
Service Instructions
CONTENTS Page
SAFETY CONSIDERATIONS ................ 1-6
General ................................... 1
RECEIVING AND INSTALLATION ........... 7-14
Step 1 — Check Equipment ................ 7
• IDENTIFY UNIT
• INSPECT SHIPMENT
Step 2 — Provide Unit Support .............. 7
• ROOF CURB
• SLAB MOUNT
• FLUSH MOUNT
Step 3 — Field Fabricate Ductwork .......... 7
Step 4 — Provide Clearances ............... 7
Step 5 — Rig and Place Unit ................ 7
• UNITS WITHOUT BASE RAIL
• UNITS WITH OPTIONAL BASE RAIL
Step 6 — Connect Condensate Drain ........ 8
Step 7 — Install Flue Hood ................. 8
Step 8 — Install Gas Piping ................. 8
Step 9 — Install Duct Connections .......... 10
• CONFIGURING UNITS FOR DOWNFLOW
(Vertical) DISCHARGE
Step 10 — Install Electrical Connections ..... 12
• HIGH-VOLTAGE CONNECTIONS
• SPECIAL PROCEDURES FOR 208-V
OPERATION
• CONTROL VOLTAGE CONNECTIONS
• HEAT ANTICIPATOR SETTING
• TRANSFORMER PROTECTION
PRE-START-UP ............................ 15
START-UP ................................15-25
MAINTENANCE ............................26-29
TROUBLESHOOTING ......................30-32
START-UP CHECKLIST .....................CL-1
NOTE TO INSTALLER — READ THESE INSTRUC-
TIONS CAREFULLY AND COMPLETELY before install-
ing this unit (Fig. 1).Also, make sure the User’s Manual and
Replacement Guide are left with the unit after installation.
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment
can be hazardous due to system pressure and electrical com-
ponents. Only trained and qualified personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func-
tions of cleaning coils and filters.All other operations should
be performed by trained service personnel. When working
on air-conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit, and other safety
precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire ex-
tinguisher available for all brazing operations.
Understand the signal words — DANGER, WARNING,
and CAUTION. Danger identifies the most serious hazards
which will result in severe personal injury or death. Warning
indicates a condition that could result in personal injury. Cau-
tion is used to identify unsafe practices which would result
in minor personal injury or product property damage.
Improper installation, adjustment, alteration, service, main-
tenance, or use can cause carbon monoxide poisoning,
fire, or an explosion which can result in personal injury
or unit damage. Consult a qualified installer, service agency,
or gas supplier for information or assistance. The quali-
fied installer or agency must use only factory-authorized
kits or accessories when modifying this product.
Before performing service or maintenance operations on
unit, turn off gas supply then unit main power switch.
Electrical shock could cause personal injury.
General — The 48HX units (see Fig. 1) are fully self-
contained, combination electric heat pump units with
gas-fired back-up heat. The units are designed for outdoor
installation. See Fig. 2-5 for unit dimensions. All unit sizes
have discharge openings for both horizontal and down-
flow configurations, and are factory shipped with all 4 duct
openings covered. Units may be installed either on a rooftop
or a ground-level cement slab. See Fig. 6 for roof curb
dimensions.
Fig.1—Typical 48HX Unit Shown with Optional
Base Rail
48HX030-060
Dual Fuel Heat Pump Units
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 5a 5a PC 111 Catalog No. 534-722 Printed in U.S.A. Form 48HX-3SI Pg 1 9-98 Replaces: 48HX-2SI

UNIT
48HX ELECTRICAL CHARACTERISTICS UNIT WEIGHT CORNER WEIGHT
(lb/kg)
lbkgABCD
030040 208/230-1-60, 208/230-3-60 346 157 99/45 69/31 120/55 58/26
030060 208/230-1-60, 208/230-3-60 358 163 102/46 72/33 123/56 61/28
UNIT
48HX
CENTER OF GRAVITY
(in./mm)
XYZ
030040 26.99/686 22.62/575 12.65/321
030060 26.90/684 22.62/575 12.65/321
NOTES:
1. Clearances must be maintained to prevent recircu-
lation of air from outdoor-fan discharge.
2. indicates center of gravity.
REQ’D CLEARANCES FOR SERVICING. in. (mm)
Duct Panel .....................................0
Unit Top .................................36(914.4)
Side Opposite Ducts ........................36(914.4)
Compressor Access ........................36(914.4)
(Except for NEC requirements)
REQ’D CLEARANCES TO COMBUSTIBLE MAT’L. in. (mm)
Maximum Extension of Overhangs .............48(1219.2)
Unit Top .................................14(355.6)
Duct Side of Unit ............................2(50.8)
Side Opposite Ducts ........................14(355.6)
Bottom of Unit ...................................0
Flue Panel ...............................36(914.4)
NEC (National Electrical Code) REQ’D CLEARANCES. in. (mm)
Between Units, Control Box Side ..............42(1066.8)
Unit and Ungrounded Surfaces, Control Box Side . . . 36 (914.4)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Control Box Side .................42(1066.8)
Fig. 2 — Unit Dimensions, 48HX030 and 036 Without Base Rail
2

UNIT
48HX ELECTRICAL CHARACTERISTICS UNIT WEIGHT CORNER WEIGHT
(lb/kg)
lbkgABCD
030040 208/230-1-60, 208/230-3-60 370 169 105/48 75/34 126/57 64/29
030060 208/230-1-60, 208/230-3-60 382 174 108/49 78/35 129/59 67/30
UNIT
48HX
CENTER OF GRAVITY
(in./mm)
XYZ
030040 26.85/682 23.25/590 15.96/405
030060 26.75/680 23.25/590 15.96/405
NOTES:
1. Clearances must be maintained to prevent recir-
culation of air from outdoor-fan discharge.
2. indicates center of gravity.
REQ’D CLEARANCES FOR SERVICING. in. (mm)
Duct Panel ...............................0
Unit Top ...........................36(914.4)
Side Opposite Ducts ..................36(914.4)
Compressor Access ..................36(914.4)
(Except for NEC requirements)
REQ’D CLEARANCES TO COMBUSTIBLE MAT’L.
in. (mm)
Maximum Extension of Overhangs .......48(1219.2)
Unit Top ...........................14(355.6)
Duct Side of Unit ..................... 2(50.8)
Side Opposite Ducts ..................14(355.6)
Bottom of Unit .............................0
Flue Panel .........................36(914.4)
NEC (National Electrical Code) REQ’D CLEARANCES
in. (mm)
Between Units, Control Box Side ........42(1066.8)
Unit and Ungrounded Surfaces, Control
Box Side .........................36(914.4)
Unit and Block or Concrete Walls and Other
Grounded Surfaces, Control Box Side ....42(1066.8)
Fig. 3 — Unit Dimensions, 48HX030 With Optional Base Rail
3

UNIT
48HX ELECTRICAL CHARACTERISTICS UNIT WEIGHT CORNER WEIGHT
(lb/kg)
lb kg A B C D
036060/080 208/230-1-60, 208/230-3-60 460-3-60 432 196 111/50 88/40 160/73 73/33
048080/100 208/230-1-60, 208/230-3-60 432 196 111/50 88/40 160/73 73/33
060080/100 208/230-1-60, 208/230-3-60 463 210 119/54 96/44 167/76 81/37
UNIT
48HX
CENTER OF GRAVITY
(in./mm)
XYZ
036060/080 28.38/720 22.75/604 15.35/390
048080/100 28.38/720 23.75/604 15.35/390
060080/100 28.06/713 23.60/599 15.35/390
NOTES:
1. Clearances must be maintained to prevent recir-
culation of air from outdoor-fan discharge.
2. indicates center of gravity.
REQ’D CLEARANCES FOR SERVICING. in. (mm)
Duct Panel ......................................0
Unit Top ..................................36(914.4)
Side Opposite Ducts .........................36(914.4)
Compressor Access .........................36(914.4)
(Except for NEC requirements)
REQ’D CLEARANCES TO COMBUSTIBLE MAT’L. in. (mm)
Maximum Extension of Overhangs ..............48(1219.2)
Unit Top ..................................14(355.6)
Duct Side of Unit .............................2(50,8)
Side Opposite Ducts .........................14(355.6)
Bottom of Unit ....................................0
Flue Panel ................................36(914.4)
NEC (National Electrical Code) REQ’D CLEARANCES. in. (mm)
Between Units, Control Box Side ...............42(1066.8)
Unit and Ungrounded Surfaces, Control Box Side ....36(914.4)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Control Box Side ...................42(1066.8)
Fig. 4 — Unit Dimensions, 48HX036-060 Without Base Rail
4

UNIT
48HX ELECTRICAL CHARACTERISTICS UNIT WEIGHT CORNER WEIGHT
(lb/kg)
lb kg A B C D
036060/080 208/230-1-60, 208/230-3-60, 460-3-60 456 207 117/53 94/43 166/75 79/36
048080/100 208/230-1-60, 208/230-3-60 456 207 117/53 94/43 166/75 79/36
060080/100 208/230-1-60, 208/230-3-60 487 221 125/57 102/46 173/79 87/40
UNIT
48HX
CENTER OF GRAVITY
(in./mm)
XYZ
036060/080 28.16/716 24.50/622 18.66/474
048080/100 28.16/716 24.50/622 18.66/474
060080/100 27.90/709 24.30/618 18.66/474
NOTES:
1. Clearances must be maintained to prevent recir-
culation of air from outdoor-fan discharge.
2. indicates center of gravity.
Fig. 5 — Unit Dimensions, 48HX036-060 With Optional Base Rail
REQ’D CLEARANCES FOR SERVICING. in. (mm)
Duct Panel ......................................0
Unit Top ..................................36(914.4)
Side Opposite Ducts .........................36(914.4)
Compressor Access .........................36(914.4)
(Except for NEC requirements)
REQ’D CLEARANCES TO COMBUSTIBLE MAT’L. in. (mm)
Maximum Extension of Overhangs ..............48(1219.2)
Unit Top ..................................14(355.6)
Duct Side of Unit .............................2(50.8)
Side Opposite Ducts .........................14(355.6)
Bottom of Unit ....................................0
Flue Panel ................................36(914.4)
NEC (National Electrical Code) REQ’D CLEARANCES. in. (mm)
Between Units, Control Box Side ...............42(1066.8)
Unit and Ungrounded Surfaces, Control Box Side ....36(914.4)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Control Box Side ...................42(1066.8)
5

PART NUMBER ‘‘A’’
FLAT CPRFCURB001A00 89[203] CPRFCURB002A00 119[279]
CPRFCURB003A00 149[356]
NOTES:
1. Roof curb must be set up for unit being installed.
2. Seal strip must be applied as required for unit being installed.
3. Dimensions in [ ] are in millimeters.
4. Roof curb is made of 16 gage steel.
5. Attach ductwork to curb (flanges of duct rest on curb).
6. Service clearance 4 ft on each side.
7. Direction of airflow.
8. Insulated panels: 1-in. thick fiberglass 1 lb density.
Fig. 6 — Roof Curb Dimensions
6

RECEIVING AND INSTALLATION
Step 1 — Check Equipment
IDENTIFYUNIT —The unit model number and serial num-
ber are stamped on unit identification plate. Check this
information against shipping papers and job data.
INSPECT SHIPMENT— Inspect for shipping damage while
unit is still on shipping pallet. If unit appears to be damaged
or is torn loose from its anchorage, have it examined by trans-
portation inspectors before removal. Forward claim papers
directly to transportation company. Manufacturer is not re-
sponsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify
the nearest Carrier Air Conditioning office if any item is
missing.
To prevent loss or damage, leave all parts in original pack-
ages until installation.
Step 2 — Provide Unit Support
ROOF CURB — Install accessory roof curb in accordance
with instructions shipped with curb. See Fig. 6 for roof curb
dimensions. Install insulation, cant strips, roofing, and flash-
ing. Ductwork must be attached to curb.
IMPORTANT: The gasketing of the unit to the roof
curb is critical for a watertight seal. Install gasketing
material supplied with the roof curb. Improperly ap-
plied gasketing can also result in air leaks and poor
unit performance.
Curb should be level to within
1
⁄ 4 inch. See Fig. 7. This
is necessary for unit drain to function properly. Refer to
accessory roof curb installation instructions for additional
information as required.
To remove wood support under unit (with base rail only),
loosen 4 screws above rigging holes and slide assembly out
through rectangular hole.
SLAB MOUNT — Place the unit on a solid, level concrete
pad that is a minimum of 4 in. thick with 2 in. above grade.
The slab should be flush on the front of the unit (to allow
condensate drain installation) and should extend 2 in. on the
three remaining sides of the unit. See Fig. 8. Install a 6-in.
gravel apron in front of outdoor-air inlets to prevent obstruc-
tion of airflow by grass or shrubs. Do not secure the unit to
the slab except when required by local codes.
To remove wood support under unit (with base rail only),
loosen 4 screws above rigging holes and slide assembly out
through rectangular hole.
FLUSH MOUNT — Place side of unit with duct panel
flush against transition. On units with optional base rails, the
skirt on duct-panel side of unit can be removed or relocated
to allow unit to be mounted flush against transitions that ex-
tend below basepan of unit. To move skirt, proceed as
follows:
1. Remove 4 screws holding skirt to base rail. Retain screws.
2. Remove skirt or slide skirt inwards until alternate clear-
ance holes align with base rails.
3. Secure with screws removed in Step 1. Holes align with
base rails.
To remove wood support under unit (with base rail only),
loosen 4 screws above rigging holes and slide assembly out
through rectangular hole.
Step 3 — Field Fabricate Ductwork — Secure all
ducts to roof curb and building structure on vertical dis-
charge units. Do not connect ductwork to unit. For horizon-
tal applications, attach ductwork to flanges on horizontal
discharge openings. All ductwork should be secured to the
flanges. Insulate and weatherproof all external ductwork, joints,
and roof openings with counter flashing and mastic in ac-
cordance with applicable codes.
Ducts passing through an unconditioned space must be
insulated and covered with a vapor barrier.
If a plenum return is used on a vertical unit, the return
should be ducted through the roof deck to comply with ap-
plicable fire codes.
A minimum clearance is not required around ductwork.
Cabinet return-air static shall not exceed −.25 in. wg.
Step 4 — Provide Clearances — The required mini-
mum operating and service clearances are shown in
Fig. 2-5. Adequate combustion, ventilation, and outdoor air
must be provided.
Do not restrict outdoor airflow. An air restriction at ei-
ther the outdoor-air inlet or the fan discharge can be det-
rimental to compressor life.
The outdoor fan pushes air through the outdoor coil and
discharges it through the bank of louvers in the top cover,
the decorative grille on the right side of the unit, and the
compressor access panel. Be sure that the fan discharge does
not recirculate to the outdoor coil. Do not locate the unit in
either a corner or under an overhead obstruction. The mini-
mum clearance of a partial overhang (such as a normal house
overhang) is 48-inches. The maximum horizontal extension
of a partial overhang must not exceed 48 inches.
Provide a minimum clearance of 42 in. for the control box
side next to a block wall or any other grounded surface. Pro-
vide a minimum clearance of 42 in. between the control box
side of unit and any electrically powered device, for ex-
ample, another unit.
Do not place the unit where water, ice, or snow from an
overhang or roof will damage or flood the unit. Do not in-
stall the unit on carpeting, tile, or other combustible mate-
rials. The unit may be installed on wood flooring or on
Class A, B, or C roof covering materials.
Step 5 — Rig and Place Unit
When installing the unit on a rooftop, be sure the roof
will support the additional weight. Refer to Fig. 2-5 for
corner weight information.
Use spreader bars or crate top when rigging the unit. The
units must be rigged for lifting as shown in Fig. 9. Refer to
Table 1 for operating weight and to Fig. 2-5 for corner weights.
MAXIMUM ALLOWABLE
DIFFERENCE (in.)
A-B B-C A-C
1
⁄ 21 ⁄ 41 ⁄ 4
Fig. 7 — Unit Leveling Tolerances
7

Use extreme caution to prevent damage when moving the
unit. Unit must remain in an upright position during all rig-
ging and moving operations. The unit must be level for proper
condensate drainage; therefore, the ground-level pad or
accessory roof curb must be level before setting the unit in
place. When a field-fabricated support is used, be sure that
the support is level and properly supports the unit.
UNITS WITHOUT BASE RAIL — If accessory rigging
brackets are to be used for rigging, install them as follows:
Secure screws and paint protectors solidly against unit
basepan to hold lifting brackets in position.
Never use lifting brackets when the temperature is be-
low −10 F.
Never exceed 200 lbs per bracket of lifting force.
Never use lifting brackets for lifting other models of air-
conditioning units or heat pumps.
Lifting point should be directly over the unit center of
gravity.
1. Position brackets as close to the corners of unit as pos-
sible. Be sure brackets are well outside of center of grav-
ity. (See Fig. 2, 4, and 9.)
2. Position paint protectors and foam strips between screws
and painted surface of unit. Tighten screws until they make
contact with the paint protectors.
3. Secure device or hook of sufficient strength to hole in bracket
as shown in detail ‘‘C’’ of Fig. 9.
4. If wood top is available, use it for a spreader bar to pre-
vent straps from damaging unit. If wood top is not avail-
able, use spreader bars of sufficient length.
UNITS WITH OPTIONAL BASE RAIL — Refer to
Fig. 9, detail A and View B-B. Lifting holes are provided in
optional base rail as shown in Fig. 9. Operating weights are
shown in Table 1. Refer to rigging instructions on unit.
Protective wood support must be removed from unit be-
fore unit is mounted to curb. Remove 4 screws that secure
support above rigging holes in rails. Slide support out through
rectangular hole in rail. See Fig. 9.
Step 6 — Connect Condensate Drain
NOTE: When installing condensate drain connection be sure
to comply with local codes and restrictions.
Model 48HX disposes of condensate water through a
3
⁄ 4 in. NPT fitting which exits through the compressor access
panel. See Fig. 2-5 for location.
Condensate water can be drained directly onto the roof in
rooftop installations (where permitted) or onto a gravel apron
in ground-level installations. Install a field-supplied conden-
sate trap at end of condensate connection to ensure proper
drainage. Make sure that the outlet of the trap is at least
1 in. lower than the drain-pan condensate connection to pre-
vent the pan from overflowing. See Fig. 10. Prime the trap
with water. When using a gravel apron, make sure it slopes
away from the unit.
If the installation requires draining the condensate water
away from the unit, install a 2-in. trap at the condensate
connection to ensure proper drainage. See Fig. 10. Make sure
that the outlet of the trap is at least 1 in. lower than the drain-
pan condensate connection to prevent the pan from over-
flowing. Prime the trap with water. Connect a drain tube
using a minimum of
3
⁄ 4 -in. PVC or
3
⁄ 4 -in. copper pipe (all
field-supplied) at the outlet end of the 2-in. trap. Do not un-
dersize the tube. Pitch the drain tube downward at a slope of
at least one in. for every 10 ft of horizontal run. Be sure to
check the drain tube for leaks.
Step 7 — Install Flue Hood — The flue hood as-
sembly is shipped screwed to the control box in the burner
compartment. Remove the burner access panel to locate the
assembly.
For units being installed in California Air Quality Man-
agement Districts which require NO
X
emissions of
40 nanograms/joule or less, kit CRLOWNOX001A00 must
be installed.
The venting system is designed to ensure proper vent-
ing. The flue hood assembly must be installed as indi-
cated in this section of the unit installation instructions.
Install the flue hood as follows (refer to Fig. 2-5):
1. This installation must conform with local building codes
and with the National Fuel Gas Code (NFGC), American
National Standards Institute (ANSI) Z223.1 latest revi-
sion (in Canada, CAN/CGA [Canadian Gas Association]
B149.1, [2]-M86) or NFPA (National Fire Protection
Association) 54, latest revision TIA-54-84-1. Refer to
Provincial and local plumbing or wastewater codes and
other applicable local codes.
2. Remove from shipping location. Place vent cap assembly
over flue panel. Orient screw holes in vent cap with holes
in the flue panel.
3. Secure flue hood to flue panel by inserting a single
screw on the right side, the left side, and the top of flue
hood.
Step 8 — Install Gas Piping — The gas supply pipe
enters the unit through the access hole provided. The gas
connection to the unit is made to the
1
⁄ 2 -in. FPT gas inlet on
the manual shutoff or gas valve.
Install a gas supply line that runs to the heating section.
Refer to Table 2 and the NFGC for gas pipe sizing. Black
iron pipe must be used for connections inside the unit. Check
the local utility for recommendations concerning existing lines.
Size gas supply piping for 0.5 in. wg maximum pressure drop.
Never use pipe smaller than the
1
⁄ 2 -in. FPT gas inlet on the
unit gas valve.
Fig. 8 — Slab Mounting Details
8

Table 1 — Physical Data
UNIT SIZE 48HX 030040 030060 036060 036080 048080 048100 060080 060100
NOMINAL CAPACITY (tons) 2
1
⁄ 2 2
1
⁄ 2 334455
OPERATING WEIGHT (lb)
Without Base Rail 346 358 432 432 432 432 463 463
With Optional Base Rail 370 382 456 456 456 456 487 487
COMPRESSOR Scroll
Quantity 1
REFRIGERANT R-22
Charge (lb) 5.6 5.6 8.6 8.6 7.8 7.8 8.1 8.1
OUTDOOR COIL
Rows...Fins/in. 2...17 2...17 2...17 2...17 2...17 2...17 2...17 2...17
Face Area (sq ft) 7.00 7.00 8.66 8.66 8.66 8.66 8.66 8.66
OUTDOOR FAN (Propeller)
Nominal Cfm 2200 2200 2200 2200 2400 2400 2400 2400
Diameter (in.) 20 20 20 20 20 20 20 20
Motor Hp
1
⁄ 41 ⁄ 41 ⁄ 41 ⁄ 41 ⁄ 31 ⁄ 31 ⁄ 31 ⁄ 3
Motor Rpm 1100 1100 1100 1100 1100 1100 1100 1100
INDOOR COIL
Rows...Fins/in. 3...15 3...15 4...15 4...15 4...15 4...15 4...15 4...15
Face Area (sq ft) 3.6 3.6 4.5 4.5 4.5 4.5 4.5 4.5
INDOOR FAN (Centrifugal)*
Nominal Airflow (Cfm) 1000 1000 1150 1150 1600 1600 1800 1800
Size (in.) 10x10 10x10 10x10 10x10 10x10 10x10 10x10 10x10
Motor Hp
1
⁄ 41 ⁄ 41 ⁄ 41 ⁄ 2 1111
Motor Rpm 1075 1075 1100 1100 Variable Variable Variable Variable
FURNACE SECTION
Heating Input†
(Btuh) 40,000 56,000 56,000 80,000 80,000 95,000 80,000 95,000
Burner Orifice (Qty...drill size)
Natural Gas 1...32 2...41 2...41 2...32 2...32 2...30 2...32 2...30
Propane Gas 1...41 2...46 2...46 2...42 2...42 2...41 2...42 2...41
RETURN-AIR FILTERS**
Throwaway (in.) 24x24 24x24 24x30 24x30 24x30 24x30 24x30 24x30
*Sizes 048 and 060 indoor fans are equipped with an integrated con-
trol motor (ICM). The ICM provides variable speed.
†Based on an altitude of 0 to 2000 feet.
**Required filter sizes shown are based on the ARI (Air Conditioning
& Refrigeration Institute) rated heating airflow at a velocity of
300 ft/min for throwaway type or 450 ft/min for high capacity type.
Recommended filters are 1-in. thick.
All panels must be in place when rigging.
NOTICE TO RIGGERS
Hook rigging shackles through holes in lifting brackets, as shown in
Details ‘‘A’’ and ‘‘C.’’ Lifting brackets to be centered around the unit
center of gravity. Use wooden top skid when rigging, to prevent rig-
ging straps from damaging unit. On units with rails, remove 4 screws
to slide wood support through rectangular hole in rail.
CHART ‘‘A’’ — UNITS WITH OPTIONAL BASE RAIL
UNIT SIZE
48HX
SHIPPING
WEIGHT AB
Lb Kg in. mm in. mm
030 401 182 22.6 575 32.2 817
036 477 217 21.2 537 38.2 969
048 477 217 21.2 537 38.2 969
060 506 230 21.5 546 38.2 969
CHART ‘‘B’’ — UNITS WITHOUT BASE RAIL
UNIT SIZE
48HX
SHIPPING
WEIGHT CD
Lb Kg in. mm in. mm
030 377 171 22.4 568 28.2 715
036 453 206 21.0 532 34.2 867
048 453 206 21.0 532 34.2 867
060 482 219 21.3 542 34.2 867
Fig. 9 — Suggested Rigging
9

For natural gas applications, the gas pressure at unit gas
connection must not be less than 4.0 in. wg or greater than
13 in. wg while the unit is operating. For propane applica-
tions, the gas pressure must not be less than 4.0 in. wg or
greater than 13 in. wg at the unit connection.
When installing the gas supply line, observe local codes
pertaining to gas pipe installations. Refer to the NFGC
ANSI Z223.1 latest revision NFPA latest edition (in
Canada, CAN/CGA B149.1, (2)-M86). In the absence of
local building codes, adhere to the following pertinent
recommendations:
1. Avoid low spots in long runs of pipe. Grade all pipe
1
⁄ 4 inch in every 15 ft to prevent traps. Grade all hori-
zontal runs downward to risers. Use risers to connect to
heating section and to meter.
2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate straps,
hangers, etc. Use a minimum of one hanger every 6 ft.
For pipe sizes larger than
1
⁄ 2 in., follow recommendations
of national codes.
3. Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.
4. Install sediment trap in riser leading to heating section
per Fig. 11. This drip leg functions as a trap for dirt and
condensate.
5. Install an accessible, external, manual main shutoff valve
in gas supply pipe within 6 ft of heating section.
6. Install ground-joint union close to heating section be-
tween unit gas valve and external manual gas shutoff
valve.
7. Pressure-test all gas piping in accordance with local and
national plumbing and gas codes.
NOTE: The gas valve in the unit is subject to failure if
exposed to pressures exceeding 0.5 psig. When pressur-
izing the gas line above 0.5 psig, disconnect the union
located between the manual shutoff and the gas valve in
the unit; this will avoid unit gas valve failure.
Never use a match or other open flame when check-
ing for gas leaks. Never purge gas line into com-
bustion chamber. Failure to follow this warning could
result in an explosion causing personal injury or death.
8. Using a soap and water solution, check for gas leaks at
all piping connections inside and outside the unit.
Step 9 — Install Duct Connections — The unit
has duct flanges on the supply- and return-air openings on
the side and bottom of the unit. See Fig. 2-5 for connection
sizes and locations.
CONFIGURING UNITS FOR DOWNFLOW (Vertical)
DISCHARGE
For vertical supply and return units, tools or parts
could drop into ductwork and cause an injury. Install
90-degree turns in the supply and return ductwork be-
tween the unit and the conditioned space. If a 90-degree
elbow cannot be installed, then grilles of sufficient strength
and density should be installed to prevent objects from
falling into the conditioned space.
Before performing service or maintenance operations on
the system, turn off gas supply, then main power to unit.
Failure to follow this warning could result in electrical
shock and personal injury.
1. Open all electrical disconnects before starting any serv-
ice work.
2. Remove return duct cover located on duct panel.
Figure 12 shows duct cover removed. Save duct cover
and screws.
3. Locate lances in basepan insulation that are placed
over the perimeter of the vertical duct opening cover
(Fig. 13).
4. Using a straight edge and sharp knife, cut and remove
the insulation around the perimeter of the cover. Re-
move and save 5 screws securing the cover to the base-
pan and slide out the cover. Discard the cover
(Fig. 14).
5. Remove supply duct cover located on duct panel.
Figure 12 shows duct cover removed. Save duct cover
and screws.
6. Remove and discard 2 screws which secure vertical dis-
charge opening cover to basepan (Fig. 15). Slide cover
forward to disengage, then tilt and remove cover through
vertical discharge opening in bottom of unit. Discard duct
cover (Fig. 16).
Collect ALL screws that were removed. Do not leave
screws on rooftop as permanent damage to the roof
may occur.
Fig. 10 — Condensate Trap
Fig. 11 — Sediment Trap
10

7. If unit ductwork is to be attached to vertical opening
flanges on the unit basepan (jackstand applications only),
do so at this time.
8. It is recommended that the basepan insulation around
the perimeter of the vertical return-air opening be se-
cured to the basepan with aluminum tape. Applicable
local codes may require aluminum tape to prevent ex-
posed fiberglass.
9. Cover both horizontal duct openings with the duct cov-
ers from Steps 2 and 5. Make sure opening is air- and
watertight.
10. After completing unit conversion, perform all safety checks
and power up unit.
NOTE: The design and installation of the duct system must
be in accordance with the standards of the NFPA for instal-
lation of nonresidence-type air conditioning and ventilating
systems, NFPA 90A or residence-type, NFPA 90B; and/or
local codes and residence-type, NFPA90B; and/or local codes
and ordinances.
SUPPLY DUCT OPENING RETURN DUCT OPENING
Fig. 12 — Supply and Return Duct Openings
Fig. 13 — Lance Location for Vertical Duct
Opening Cover
Fig. 14 — Vertical Duct Cover Removed
Fig. 15 — Removal of Vertical Discharge
Opening Cover
11

Table 2 — Maximum Gas Flow Capacity*
NOMINAL
IRON PIPE,
SIZE
(in.)
INTERNAL
DIAMETER
(in.)
LENGTH OF PIPE, FT†
10 20 30 40 50 60 70 80 90 100 125 150 175 200
1
⁄ 2 .622 175 120 97 82 73 66 61 57 53 50 44 40 — —
3
⁄ 4 .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
11.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
1
1
⁄ 4 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280
1
1
⁄ 2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5-in. wg
(based on a 0.60 specific gravity gas). Refer to Table C-4, National Fire ProtectionAssociation NFPA54.
†This length includes an ordinary number of fittings.
Adhere to the following criteria when selecting, sizing,
and installing the duct system:
1. Units are shipped with all 4 duct openings covered. Re-
move appropriate panels for intended installation.
2. Select and size ductwork, supply-air registers, and return-
air grilles according toAmerican Society of Heating, Re-
frigeration and Air Conditioning Engineers (ASHRAE)
recommendations.
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 weathertight and airtight seal.
4. All units must have field-supplied filters or accessory fil-
ter rack installed in the return-air side of the unit. Rec-
ommended sizes for filters are shown in Table 1.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.
6. Adequately insulate and weatherproof all ductwork lo-
cated outdoors. Insulate ducts passing through uncon-
ditioned space, and use vapor barrier in accordance with
latest issue of Sheet Metal andAir Conditioning Contrac-
tors National Association (SMACNA) and Air Condi-
tioning Contractors of America (ACCA) minimum
installation standards for heating and air conditioning sys-
tems. 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.
Step 10 — Install Electrical Connections
The unit cabinet must have an uninterrupted, unbroken
electrical ground to minimize the possibility of personal
injury if an electrical fault should occur. This ground
may consist of an electrical wire connected to the unit
ground lug in the control compartment, or conduit ap-
proved for electrical ground when installed in accor-
dance with NEC (National Electrical Code) ANSI/
NFPA (latest edition) (in Canada, Canadian Electrical
Code CSA [Canadian Standards Association] C22.1) and
local electrical codes. Do not use gas piping as an elec-
trical ground. Failure to adhere to this warning could
result in personal injury or death.
Failure to follow these precautions could result in dam-
age to the unit being installed:
1. Make all electrical connections in accordance with
NECANSI/NFPA(latest edition) and local electrical codes
governing such wiring. In Canada, all electrical connec-
tions 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. Be sure that high-voltage power to unit is within oper-
ating voltage range indicated on unit rating plate.
4. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc. On
3-phase units, ensure phases are balanced within 2 per-
cent. Consult local power company for correction of
improper voltage and/or phase imbalance.
HIGH-VOLTAGE CONNECTIONS (Fig. 17) — 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 for maximum
fuse/circuit breaker size and minimum circuit amps (ampac-
ity) for wire sizing. See Table 3 for electrical data.
The field-supplied disconnect switch box may be mounted
on the unit over the high-voltage inlet hole when the
standard power and low-voltage entry points are used. See
Fig. 2-5 for acceptable location.
Fig. 16 — Vertical Discharge Cover
Removed
12

Power Entry
1. Remove knockouts in fixed compressor panel located on
duct panel side of unit.
2. Route high-voltage leads into high-voltage terminal box.
3. Connect ground wire to green-yellow wire using field-
supplied splice.
4. Connect power wires to unit high-voltage leads.
5. On 3-phase units, locate blue wire projecting from com-
pressor junction box. Cut wire at partition and route into
high-voltage junction box through grommet in back of
junction box.
6. On 3-phase units, strip back blue lead and connect to third
leg of the power wires. See Fig. 17.
Table 3 — Electrical Data
UNIT
SIZE V-PH-Hz VOLTAGE
RANGE COMPRESSOR OUTDOOR-FAN MOTOR INDOOR-FAN MOTOR POWER SUPPLY AWG 60C
MIN WIRE
SIZE MAX WIRE
LENGTH (ft)
Min Max RLA LRA FLA FLA MCA MOCP*
030 208/230-1-60 187 253 15.0 73 1.4 2.6 22.8 30 10 100
208/230-3-60 187 253 10.1 71 1.4 2.8 16.6 25 12 75
036 208/230-1-60 187 253 16.0 88 1.2 2.6 24.4 40 10 90 208/230-3-60 187 253 10.3 77 1.2 2.6 17.3 25 12 65
460-3-60 414 506 5.1 39 0.7 1.3 8.7 10 14 100
048 208/230-1-60 187 253 26.4 129 1.4 7.2 41.6 60 6 100
208/230-3-60 187 253 15.0 99 1.4 7.2 27.4 40 10 70
060 208/230-1-60 187 253 32.1 169 2.1 7.2 49.4 60 6 100
208/230-3-60 187 253 19.3 123 2.1 7.2 33.4 50 8 100
LEGEND
AWG — American Wire Gage
FLA — Full Load Amps
HACR — Heating, Air Conditioning and
Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
RLA — Rated Load Amps
UL — Underwriters’ Laboratories
*Fuse or HACR breaker.
NOTES:
1. In compliance with NEC (National Electrical Code) requirements
for multimotor and combination load equipment (refer to NEC
Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. The UL, Canada, units may
be fuse or circuit breaker.
2. Minimum wire size is based on 60 C copper wire. If other than
60 C wire is used, or if length exceeds wire length in table, de-
termine size from NEC.
3. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the percent of voltage imbalance.
% Voltage imbalance
max voltage deviation from average voltage
= 100 x average voltage
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v 452 + 464 + 455
Average Voltage = 3
1371
=3
= 457
Determine maximum deviation from average voltage.
(AB) 457 − 452=5v
(BC) 464 − 457=7v
(AC) 457 − 455=2v
Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7
% Voltage Imbalance = 100 x 457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
LEGEND
Field Control-Voltage Wiring
Field High-Voltage Wiring
NOTE: Use blue wire for 3-phase units only.
Fig. 17 — High- and Control-Voltage
Connections
13

SPECIAL PROCEDURES FOR 208-V OPERATION
Make sure that the gas supply then the power supply to
the unit is switched OFF before making any wiring
changes. Electrical shock can cause personal injury or
death.
1. Disconnect the red transformer-primary lead from the con-
tactor. See unit wiring label.
2. Remove the wirenut from the terminal on the end of the
blue transformer-primary lead.
3. Save the wirenut.
4. Connect the blue lead to the contactor terminal from which
the red lead was disconnected.
5. Using the wirenut removed from the blue lead, insulate
the loose terminal on the red lead.
6. Wrap the cover with electrical tape so that the metal ter-
minal cannot be seen.
CONTROLVOLTAGE CONNECTIONS — Locate the room
thermostat on an inside wall in the space to be conditioned,
where it will not be subjected to either a cooling or heating
source or direct exposure to sunlight. Mount the thermostat
4 to 5 ft above the floor.
NOTE: Do not use any type of power-stealing thermostat.
Unit control problems may result.
Use no. 18 American Wire Gage (AWG) color-coded,
insulated (35 C minimum) wires to make the control volt-
age 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.
Standard Connection (24 v) — Units Without Integrated
Control Motor (Size 030,036) — Remove knockout in com-
pressor fixed panel located below high-voltage knockout. Re-
move the rubber grommet from the installer’s packet (included
with unit) and install grommet in the knockout opening. Route
thermostat wires through grommet providing drip loop at panel.
Connect low-voltage leads as shown in Fig. 17.
Routing Control Power Wires (24 v) — Integrated Control
Motor (ICM) Units (Size 048,060) — Remove knockout in
compressor fixed access panel located below high-voltage
knockout. Remove the rubber grommet from the installer’s
packet (included with unit) and install grommet in the knock-
out opening. Route thermostat wires through grommet pro-
viding drip loop at panel. Connect low-voltage leads to the
thermostat.
The Easy Select interface board is located in the burner
section. The Easy Select interface board is factory wired to
the motor, and factory default selections are preset. See
Fig. 18.
HEAT ANTICIPATOR SETTING — The room thermostat
heat anticipator must be properly adjusted to ensure proper
heating performance. Set the heat anticipator, using an am-
meter between the W and R terminals, to determine the
exact required setting.
NOTE: For thermostat selection purposes, use 0.6 amp for
the approximate required setting.
Failure to make a proper heat anticipator adjustment will
result in improper operation, discomfort to the occupants
of the conditioned space, and inefficient energy utilization;
however, the required setting may be changed slightly
to provide a greater degree of comfort for a particular
installation.
Recommended thermostat and subbase is as follows:
TYPE THERMOSTAT
PART NO. SUBBASE PART NO.
2-Stage Heat and 1-Stage
Cool, Auto, Changeover HH07AT171 HH93AZ188
TRANSFORMER PROTECTION — The unit transformer
protection may be one of 2 types.
The first transformer type may contain an auto. reset over-
current protector for control circuit protection. If this device
trips, it may reset without warning, starting the heating or
cooling section of this product. Use caution when servicing;
if overcurrent protector continues to trip, there is a problem
in the low-voltage electrical circuit, such as an electrical short,
ground, or transformer overload. Disconnect power, correct
the condition, and check for normal unit operation.
The second transformer type is of the energy-limiting type.
It is set to withstand a 30-second overload or shorted
secondary condition.
There is also a 5-amp fuse on integrated gas control (IGC)
board and Easy Select Interface Board to provide additional
overcurrent protection.
LEGEND
IFO — Indoor Fan On
JW — Jumper Wire
Fig. 18 — Easy Select Interface Board
14

PRE-START-UP
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 are disconnected.
4. Relieve and recover all refrigerant from system be-
fore touching or disturbing anything inside terminal
box if refrigerant leak is suspected around compres-
sor terminals.
5. Never attempt to repair soldered connection while re-
frigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To re-
move a component, wear protective goggles and pro-
ceed as follows:
a. Shut off gas supply and then electrical power to
unit.
b. Relieve and recover all refrigerant from system
using both high- and low-pressure ports.
c. Cut component connecting tubing with tubing cut-
ter and remove component from unit.
d. Carefully unsweat remaining tubing stubs when
necessary. Oil can ignite when exposed to torch
flame.
Proceed as follows to inspect and prepare the unit for ini-
tial start-up:
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 bro-
ken lines, loose parts, disconnected wires, etc.
b. Inspect for oil at all refrigerant tubing connections and
on unit base. Detecting oil generally indicates a re-
frigerant leak. Leak-test all refrigerant tubing connec-
tions using electronic leak detector, halide torch, or
liquid-soap solution. If a refrigerant leak is detected,
see Check for Refrigerant Leaks section below.
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:
Do not purge gas supply into the combustion cham-
ber. Do not use a match or other open flame to check
for gas leaks. Failure to follow this warning could
result in an explosion causing personal injury or death.
a. Before lighting the unit for the first time, perform the
following: If the gas supply pipe was not purged be-
fore connecting the unit, it will be full of air. It is rec-
ommended that the ground joint union be loosened,
and the supply line be allowed to purge until the odor
of gas is detected. Never purge gas lines into a com-
bustion chamber. Immediately upon detection of gas
odor, retighten the union. Allow 5 minutes to elapse,
then light unit.
b. Make sure that outdoor-fan blade is correctly posi-
tioned in fan orifice. Leading edge of outdoor-fan blade
should be
1
⁄ 2 in. maximum from plastic fan orifice (see
Fig. 19).
c. Make sure that air filter(s) is in place.
d. Make sure that condensate drain trap is filled with wa-
ter to ensure proper drainage.
e. Make sure that all tools and miscellaneous loose parts
have been removed.
START-UP
Check for Refrigerant Leaks — Proceed as follows
to locate and repair a refrigerant leak and to charge the unit:
1. Locate leak and make sure that refrigerant system pres-
sure has been relieved and reclaimed from both high- and
low-pressure ports.
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 and recover refrigerant from 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 refrigerant
to compensate for internal volume of filter drier.
Fig. 19 — Fan Blade Clearance
15

Start Up Heating Section and Make
Adjustments
Complete the required procedures given in Pre-Start-Up
section on page 15 before starting the unit.
Do not jumper any safety devices when operating the unit.
Make sure that burner orifices are properly aligned. Un-
stable operation may occur when the burner orifices in the
manifold are misaligned.
Follow the lighting instructions on the heating section
operation label (located inside the burner or blower access
door) to start the heating section.
NOTE: Make sure that gas supply has been purged, and that
all gas piping has been checked for leaks.
CHECK HEATING CONTROL — Start and check the unit
for proper heating control operation as follows: (See furnace
lighting instructions located inside burner or blower access
panel.)
1. Place the room thermostat SYSTEM switch in the HEAT
position and the fan switch in the AUTO. position.
2. Ensure that OAT (Outdoor-Air Thermostat) capillary is
above 55 F. Set the heating temperature control of the
thermostat above room temperature only enough to call
first-stage heat.
3. Observe compressor, outdoor fan, and indoor fan operate
in heat pump mode.
4. Set the heating temperature control of the thermostat enough
above room temperature to call second-stage heat.
5. Observe the induced-draft motor start.
6. After a call for second-stage heat, the main burner should
light within 5 seconds. If the burners do not light, there
is 22-second delay before another 5-second try. If the burn-
ers still do not light, this sequence is repeated. If the burn-
ers do not light within 15 minutes from the initial call for
heat, there is a lockout. To reset the control, break the
24-v power to W.
7. The indoor fan will turn on 45 seconds after the flame
has been established. The indoor fan will turn off
45 seconds after the thermostat has been satisfied.
CHECK GAS INPUT — Check gas input and manifold pres-
sure after unit start-up. (See Table 4.) If adjustment is
required proceed as follows.
The rated gas inputs shown in Table 4 are for altitudes
from sea level to 2000 ft above sea level. These inputs are
based on natural gas with a heating value of 1050 Btu/ft
3
at
0.65 specific gravity, or propane gas with a heating value
of 2500 Btu/ft
3
at 1.5 specific gravity. For elevations above
2000 ft, reduce input 4% for each 1000 ft above sea level.
When the gas supply being used has a different heating value
or specific gravity, refer to national and local codes, or con-
tact your distributor to determine the required orifice size.
These units are designed to consume the rated gas in-
puts using the fixed orifices at specified manifold pres-
sures as shown in Table 4. DO NOT REDRILL THE
ORIFICES UNDER ANY CIRCUMSTANCES.
ADJUST GAS INPUT — The gas input to the unit is
determined by measuring the gas flow at the meter or by
measuring the manifold pressure. Measuring the gas flow at
the meter is recommended for natural gas units. The mani-
fold pressure must be measured to determine the input of
propane gas units.
Measure Gas Flow (Natural Gas Units) — Minor adjust-
ment to the gas flow can be made by changing the man-
ifold pressure. The manifold pressure must be maintained
between 3.4 and 3.6 in. wg. If larger adjustments are
required, change main burner orifices following the rec-
ommendations of national and local codes.
NOTE:All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.
Proceed as follows:
1. Turn off gas supply to unit.
2. Remove pipe plug on manifold (see Fig. 20), then con-
nect manometer at this point. Turn on gas to unit.
3. Record number of seconds for gas meter test dial to make
one revolution.
4. Divide number of seconds in Step 3 into 3600 (number
of seconds in one hour).
5. Multiply result of Step 4 by the number of cu ft shown
for one revolution of test dial to obtain cu ft of gas flow
per hour.
6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 4. (Consult the local
gas supplier if the heating value of gas is not known.)
EXAMPLE: Assume that the size of test dial is 1 cu ft, one
revolution takes 50 seconds, and the heating value of the gas
is 1050 Btu/ft
3
. Proceed as follows:
1. 50 seconds to complete one revolution.
2. 3600 ÷ 50 = 72.
3.72x1=72ft
3
of gas flow/hr.
4. 72 x 1050 = 75,600 Btuh input.
Table 4 — Rated Gas Inputs at Indicated Manifold Pressures
UNIT 48HX NUMBER OF
ORIFICES
GAS SUPPLY PRESSURE
(in. wg) MANIFOLD
PRESSURE
(in. wg)
NATURAL GAS PROPANE*
Natural Propane Orifice
Drill
Size
Heating
Input
(Btuh)†
Orifice
Drill
Size
Heating
Input
(Btuh)†
Min Max Min Max Natural Propane
030040 1 4.0 13.0 4.0 13.0 3.5 3.5 32 40,000 41 40,000
030060, 036060 2 4.0 13.0 4.0 13.0 3.5 3.5 41 56,000 46 54,000
036080, 048080,
060080 2 4.0 13.0 4.0 13.0 3.5 3.5 32 80,000 42 80,000
048100, 060100 2 4.0 13.0 4.0 13.0 3.5 3.5 30 95,000 41 95,000
*When a unit is converted to propane, different size orifices must be used. See separate natural-to-propane
conversion kit instructions.
†Based on altitudes from sea level to 2000 ft above sea level. For altitudes above 2000 ft, reduce input rating
4% for each additional 1000 ft. In Canada, from 2000 ft above sea level to 4500 ft above sea level, derate
the unit 10%.
16

If the desired gas input is 80,000 Btuh, only a minor change
in the manifold pressure is required.
Observe manifold pressure and proceed as follows to ad-
just gas input:
1. Remove cover screw over regulator adjustment screw on
gas valve.
2. Turn regulator adjustment screw clockwise to increase gas
input, or turn regulator adjustment screw counterclock-
wise to decrease input. Manifold pressure must be be-
tween 3.4 and 3.6 in. wg.
Unsafe operation of the unit may result if manifold
pressure is outside this range. Personal injury or unit
damage may result.
3. Replace cover screw cap on gas valve.
4. Turn off gas supply to unit. Remove manometer from pres-
sure tap and replace pipe plug on gas valve. Turn on gas
to unit and check for leaks.
Measure Manifold Pressure (Propane Units) — The main
burner orifices on a propane gas unit are sized for the unit
rated input when the manifold pressure is 3.5 in. wg.
Proceed as follows to adjust gas input on a propane gas
unit:
1. Turn off gas to unit.
2. Remove pipe plug on manifold (see Fig. 20), then con-
nect manometer at this point.
3. Turn on gas to unit.
4. Remove cover screw over regulator adjustment screw on
gas valve.
5. Adjust regulator adjustment screw for a manifold pres-
sure reading of 3.5 in. wg. Turn adjusting screw clock-
wise to increase manifold pressure, or turn adjusting screw
counterclockwise to decrease manifold pressure.
6. Replace cover screw.
7. Turn off gas to unit. Remove manometer from pressure
tap. Replace pipe plug on gas valve, then turn on gas to
unit. Check for leaks.
CHECK BURNER FLAME — With burner access panel re-
moved, observe the unit heating operation. Watch the burner
flames to see if they are light blue and soft in appearance,
and that the flames are approximately the same for each burner.
See Fig. 21. Refer to Maintenance section for information
on burner removal.
AIRFLOWAND TEMPERATURE RISE —The heating sec-
tion for each size unit is designed and approved for heating
operation within the temperature-rise range stamped on the
unit rating plate.
Table 5 shows the approved temperature-rise range for each
heating input, and the air delivery cfm at various tempera-
ture rises. The heating operation airflow must produce a tem-
perature rise that falls within the approved range.
Refer to Indoor Airflow and Airflow Adjustments section
on page 20 to adjust heating airflow when required.
LIMIT SWITCHES — Normally-closed limit switch (LS)
completes the control circuit through the thermostat R cir-
cuit. Should the leaving-air temperature rise above the maxi-
mum allowable temperature, the limit switch opens and the
R control circuit ‘‘breaks.’’Any interruption in the R control
circuit instantly closes the gas valve and stops gas flow
to the burners and pilot. The blower motor continues to run
until LS resets.
When the air temperature at the limit switch drops to the
low-temperature setting of the limit switch, the switch closes
and completes the R control circuit. The electric-spark ig-
nition system cycles and the unit returns to normal heating
operation.
AUXILIARY LIMIT SWITCH — ROLLOUT — The func-
tion of the switch is to close the main gas valve in the event
of flame rollout. The switch is located above the main burn-
ers. When the temperature at the auxiliary switch reaches
the maximum allowable temperature, the R control circuit
trips, closing the gas valve and stopping gas flow to the burn-
ers. The indoor fan motor (IFM) and induced draft motor
continue to run until switch is reset.
PIPE
PLUG
MANIFOLD
Fig. 20 — Burner Assembly
Fig. 21 — Monoport Burners
17

Table 5 — Air Delivery (Cfm) at Indicated Temperature Rise and Rated Heating Input
HEATING
INPUT
(Btuh)
TEMPERATURE RISE °F
20 25 30 35 40 45 50 55 60 65 70 75 80
40,000 1389 1111 926 794 694 617 556 — — — — — —
56,000 1944 1556 1296 1111 972 864 778 707 — — — — —
80,000 2778 2222 1852 1587 1389 1235 1111 1010 926 855 794 — —
95,000 3299 2639 2199 1885 1649 1466 1319 1199 1100 1015 942 880 825
NOTE: Dashed areas do not fall within the approved temperature rise range of the unit.
Start Up Cooling Section and Make
Adjustments
Complete the required procedures given in the Pre-
Start-Up section on page 15 before starting the unit.
Do not jumper any safety devices when operating the
unit.
Do not operate the compressor when the outdoor tem-
perature is below 40 F (unless accessory low-ambient
kit is installed).
Do not rapid-cycle the compressor. Allow 5 minutes be-
tween ‘‘on’’ cycles to prevent compressor damage.
CHECKING COOLING CONTROL OPERATION — Start
and check the unit for proper cooling control operation as
follows:
1. Place room thermostat SYSTEM switch in OFF position.
Observe that blower motor starts when FAN switch is placed
in ON position and shuts down when FAN switch is placed
in AUTO. position.
2. Place SYSTEM switch in COOLposition and FAN switch
in AUTO. position. Set cooling control below room tem-
perature. Observe that compressor, outdoor fan, and
indoor blower motors start. Observe that cooling cycle
shuts down when control setting is satisfied. The indoor
fan will continue to run for 30 seconds.
3. When using an auto.-changeover room thermostat, place
both SYSTEM and FAN switches in AUTO. positions.
Observe that unit operates in Heating mode when tem-
perature control is set to ‘‘call for heating’’ (above room
temperature) and operates in Cooling mode when tem-
perature control is set to ‘‘call for cooling’’ (below room
temperature).
IMPORTANT: Three-phase, scroll compressor units
are direction-oriented. These units must be checked
to ensure proper compressor 3-phase power lead
orientation. If not corrected within 5 minutes, the
internal protector will shut off the compressor. The
3-phase power leads to the unit must be reversed to
correct rotation. When turning backwards, scroll com-
pressors emit elevated noise levels, and the differ-
ence between compressor suction and discharge
pressures may be dramatically lower than normal.
CHECKINGANDADJUSTING REFRIGERANT CHARGE
— The refrigerant system is fully charged with R-22 refrig-
erant, tested, and factory-sealed.
NOTE: Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R-22
charge.
A superheat charging label is attached to the inside of the
compressor access door. The label includes a ‘‘Superheat Charg-
ing Table’’ and a ‘‘Required Suction-Tube (F) Temperature’’
chart.
An accurate superheat, thermocouple-, or thermistor-type
thermometer, a sling psychrometer, and a gage manifold are
required when using the superheat charging method for evalu-
ating the unit charge. Do not use mercury or small dial-type
thermometers because they are not adequate for this type of
measurement.
When evaluating the refrigerant charge, an indicated
adjustment to the specified factory charge must always
be very minimal. If a substantial adjustment is indi-
cated, an abnormal condition exists somewhere in the
cooling system, such as insufficient airflow across ei-
ther coil or both coils.
Proceed as follows:
1. Remove caps from low- and high-pressure service
fittings.
2. Using hoses with valve core depressors, attach low- and
high-pressure gage hoses to low- and high-pressure serv-
ice fittings, respectively.
3. Start unit in Cooling mode and let unit run until system
pressures stabilize.
4. Measure and record the following:
a. Outdoor ambient-air temperature (F db).
b. Indoor inlet-air temperature (F wb).
c. Suction-tube temperature (F) at low-side service
fitting.
d. Suction (low-side) pressure (psig).
5. Using ‘‘Superheat Charging Table,’’compare outdoor-air
temperature (F db) with indoor inlet-air temperature
(F wb) to determine desired system operating superheat
temperature. See Tables 6A-6D.
6. Using ‘‘Required Suction-Tube Temperature (F)’’ table,
compare desired superheat temperature with suction (low-
side) operating pressure (psig) to determine proper suction-
tube temperature. See Table 7.
7. Compare actual suction-tube temperature with proper
suction-tube temperature. Using a tolerance of ± 3° F, add
refrigerant if actual temperature is more than 3° F higher
than proper suction-tube temperature, or remove refrig-
erant if actual temperature is more than 3° F lower than
required suction-tube temperature.
NOTE: If the problem causing the inaccurate readings is a
refrigerant leak, refer to Check for Refrigerant Leaks sec-
tion on page 15.
18

Table 6A — Superheat Charging Table, 48HX030
TEMP (F)
OUTDOOR
ENTERING AIR
INDOOR AIR — 1000 CFM
Indoor Air — Ewb (F)
54 56 58 60 62 64 66 68 70 72 74 76
65 SPH 5.5 5.5 5.5 5.5 12.5 19.6 26.6 26.9 27.2 27.5 26.5 25.4
70 SPH ****10.5 17.5 24.5 24.8 25.1 25.4 25.1 24.8
75 SPH ****8.415.5 22.5 22.8 23.1 23.4 23.8 24.2
80 SPH ****6.812.9 18.9 20.3 21.5 22.9 23.0 23.0
85 SPH ****5.110.2 15.4 17.7 20.1 22.3 22.1 21.8
90 SPH **** * 7.911.915.2 18.5 21.8 21.5 21.2
95 SPH **** * 5.68.412.7 17.0 21.2 20.8 20.6
100 SPH **** * * * 9.214.1 19.1 19.5 19.9
105 SPH **** * * * 5.711.417.1 18.2 19.3
110 SPH **** * * * 5.010.0 15.1 16.9 18.6
115 SPH **** ****8.713.0 15.5 18.0
LEGEND
Ewb — Entering Wet Bulb
SPH — Superheat at Compressor (F)
*Do not attempt to charge system under these conditions — refrigerant slugging may occur.
Table 6B — Superheat Charging Table, 48HX036
TEMP (F)
OUTDOOR
ENTERING AIR
INDOOR AIR — 1150 CFM
Indoor Air — Ewb (F)
54 56 58 60 62 64 66 68 70 72 74 76
65 SPH 28.6 28.6 28.6 30.4 32.1 33.3 34.3 33.4 32.0 30.7 29.8 28.9
70 SPH 23.8 23.8 23.8 25.5 27.2 29.5 32.3 32.0 30.9 29.7 28.6 27.6
75 SPH 19.0 19.0 19.1 20.6 22.2 25.7 30.4 30.6 29.7 28.7 27.5 26.3
80 SPH 14.9 15.0 15.0 15.8 16.5 21.1 26.5 27.7 27.8 27.8 26.6 25.3
85 SPH 10.9 10.9 10.9 10.9 10.9 16.6 22.6 24.8 25.9 26.9 25.6 24.3
90 SPH 7.6 7.7 7.7 7.0 8.3 12.6 19.1 21.5 23.4 25.3 24.4 23.6
95 SPH *****8.614.5 16.5 20.9 23.6 23.3 22.9
100 SPH ******11.314.3 17.4 20.4 21.1 21.8
105 SPH ******7.110.5 13.9 17.2 19.0 20.8
110 SPH *******7.111.716.4 18.2 19.9
115 SPH ********9.615.5 17.3 19.1
LEGEND
Ewb — Entering Wet Bulb
SPH — Superheat at Compressor (F)
*Do not attempt to charge system under these conditions — refrigerant slugging may occur.
Table 6C — Superheat Charging Table, 48HX048
TEMP (F)
OUTDOOR
ENTERING AIR
INDOOR AIR — 1600 CFM
Indoor Air — Ewb (F)
54 56 58 60 62 64 66 68 70 72 74 76
65 SPH 25.8 26.3 27.0 27.6 28.6 29.6 30.5 30.9 31.3 31.7 31.2 30.7
70 SPH 24.2 24.0 23.8 23.6 25.0 26.4 27.8 28.4 29.0 29.7 29.6 29.5
75 SPH 19.7 19.7 19.7 19.7 21.4 23.2 25.0 25.9 26.8 27.6 27.9 28.2
80 SPH 15.8 15.8 15.8 15.8 17.6 19.4 21.2 22.7 24.1 25.6 26.2 26.9
85 SPH 12.0 12.0 12.0 12.0 13.8 15.6 17.5 19.5 21.5 23.5 24.5 25.6
90 SPH 7.5 7.5 7.5 7.5 9.4 11.3 13.2 16.3 19.3 22.4 23.3 24.2
95 SPH ****5.07.09.013.1 17.1 21.2 22.0 22.8
100 SPH *******9.414.3 19.1 20.3 21.4
105 SPH *******5.711.417.1 18.6 20.1
110 SPH ********9.013.5 15.8 18.0
115 SPH ********6.710.0 13.0 16.0
LEGEND
Ewb — Entering Wet Bulb
SPH — Superheat at Compressor (F)
*Do not attempt to charge system under these conditions — refrigerant slugging may occur.
19

Table 6D — Superheat Charging Table, 48HX060
TEMP (F)
OUTDOOR
ENTERING AIR
INDOOR AIR — 1800 CFM
Indoor Air — Ewb (F)
54 56 58 60 62 64 66 68 70 72 74 76
65 SPH 21.0 21.0 21.0 21.0 22.8 24.7 26.5 27.8 29.1 30.4 29.5 28.6
70 SPH 16.5 16.5 16.5 16.5 18.8 21.1 23.5 25.2 27.0 28.8 28.2 27.6
75 SPH 12.0 12.0 12.0 12.0 14.8 17.6 20.4 22.7 24.9 27.2 26.9 26.6
80 SPH 10.5 10.5 10.5 10.5 12.7 14.9 17.1 19.8 22.5 25.2 25.4 25.5
85 SPH 9.0 9.0 9.0 9.0 10.6 12.3 13.9 17.0 20.0 23.1 23.8 24.5
90 SPH 4.5 4.5 4.5 4.5 6.5 8.5 10.5 14.3 18.1 21.9 22.7 23.5
95 SPH *****4.87.211.716.2 20.7 21.6 22.5
100 SPH ******3.68.613.6 18.6 20.0 21.4
105 SPH *******5.511.116.6 18.5 20.4
110 SPH ********10.0 15.5 17.5 19.4
115 SPH ********9.214.7 16.5 18.5
LEGEND
Ewb — Entering Wet Bulb
SPH — Superheat at Compressor (F)
*Do not attempt to charge system under these conditions — refrigerant slugging may occur.
Table 7 — Required Suction-Tube Temperature (F)*
SUPERHEAT
TEMP (F) SUCTION PRESSURE AT SERVICE PORT (psig)
61.5 64.2 67.1 70.0 73.0 76.0 79.2 82.4 85.7
035 37 39 41 43 45 47 49 51
237 39 41 43 45 47 49 51 53
439 41 43 45 47 49 51 53 55
641 43 45 47 49 51 53 55 57
843 45 47 49 51 53 55 57 59
10 45 47 49 51 53 55 57 59 61
12 47 49 51 53 55 57 59 61 63
14 49 51 53 55 57 59 61 63 65
16 51 53 55 57 59 61 63 65 67
18 53 55 57 59 61 63 65 67 69
20 55 57 59 61 63 65 67 69 71
22 57 59 61 63 65 67 69 71 73
24 59 61 63 65 67 69 71 73 75
26 61 63 65 67 69 71 73 75 77
28 63 65 67 69 71 73 75 77 79
30 65 67 69 71 73 75 77 79 81
32 67 69 71 73 75 77 79 81 83
34 69 71 73 75 77 79 81 83 85
36 71 73 75 77 79 81 83 85 87
38 73 75 77 79 81 83 85 87 89
40 75 77 79 81 83 85 87 89 91
*Temperature at suction service valve.
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
For cooling operation, the recommended airflow is 350
to 450 cfm for each 12,000 Btuh of rated cooling ca-
pacity. For heating operation, the airflow must produce
a temperature rise that falls within the range stamped on
the unit rating plate.
Table 5 shows the temperature rise at various airflow rates.
Size 030 and 036 — Table 8 shows both heating and cooling
airflows at various external static pressures for unit sizes 030
and 036. Refer to this table to determine the airflow for the
system being installed. See Table 9 for wet coil pressure drop.
NOTE: Be sure that all supply- and return-air grilles are open,
free from obstructions, and adjusted properly.
Shut off gas supply then disconnect electrical power to
the unit before changing blower speed. Electrical shock
can cause personal injury or death.
Airflow can be changed by changing the lead connections
of the blower motor.
Unit 48HX030 is factory wired for medium speed; unit
48HX036 3-speed motors are factory wired for low speed.
20