Carrier WeatherExpert 48LC User manual

Installation Instructions
48LC
WeatherExpertRSeries
Single Package Rooftop
Gas Heat/Electric Cooling Unit
with Puronr(R---410A) Refrigerant
Size: 07
NOTE: Read the entire instruction manual before starting
the installation.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 2....................
Rated Indoor Airflow (cfm) 3.....................
INSTALLATION 7...............................
Jobsite Survey 7................................
Step 1 -- Plan for Unit Location 7..................
Roof Mount 8...............................
Step 2 -- Plan for Sequence of Unit Installation 8......
Curb--Mounted Installation 8...................
Pad--Mounted Installation 8....................
Frame--Mounted Installation 8..................
Step 3 -- Inspect Unit 8...........................
Step 4 -- Provide Unit Support 8...................
Roof Curb Mount 8..........................
Slab Mount (Horizontal Units Only) 10..........
Alternate Unit Support
(In Lieu of Curb or Slab Mount) 10.............
Step 5 -- Field Fabricate Ductwork 10...............
Step 6 -- Rig and Place Unit 10....................
Positioning on Curb 11.......................
Step 7 -- Convert to Horizontal and Connect
Ductwork 11............................
Step 8 -- Install Outside Air Hood 12...............
Economizer Hood Package Removal and Setup —
Factory Option 12............................
Economizer Hood 12.........................
Step 9 -- Install Flue Hood 13.....................
Step 10 -- Install Gas Piping 13....................
Factory--Option Thru--Base Connections
(Gas Connections) 14.........................
Step 11 -- Install External Condensate Trap and Line 16..
Step 12 -- Make Electrical Connections 17...........
Field Power Supply 17........................
Units With Factory--Installed
Non--Fused Disconnect or HACR 25.............
Units Without Factory--Installed
Non--Fused Disconnect or HACR 26.............
All Units 26................................
Convenience Outlets 26.......................
HACR 28..................................
Factory--Option Thru--Base Connections
(Electrical Connections) 28....................
Units Without Thru--Base Connections 28........
Field Control Wiring 28.......................
Thermostat 28...............................
Unit without Thru--Base Connection Kit 29.......
Heat Anticipator Settings 29...................
Humidi--MiZerRSystem Control Connections 29....
Humidi--MiZer System -- Space RH Controller 29..
RTU Open Controller (Factory--Installed Option) 29...
SystemVutController (Factory--Installed Option) 29..
Integrated Staging Control (ISC) Board 30...........
ISC Board — Sequence of Operation 30...........
General 30.................................
Ventilation 30...............................
Cooling 31.................................
Humidi--MiZer System (Optional) 31.............
Economizer (Optional) 31.....................
Low Ambient Cooling Operation
Down to 40_F(4_C) 32.......................
Heating 32.................................
EconoMi$erRX (Factory--Installed Option) 33.......
Unit Installation 33..........................
Enthalpy Sensor Relocation 33.................
W7220 Economizer Controller 33................
User Interface 33............................
Keypad 33.................................
Menu Structure 34.............................
Connections and Applications 39.................
W7220 Economizer Module Wiring 39..........
Economizer Control Configurations 40............
Enthalpy Changeover Control 40...............
Enthalpy Settings 40.........................
Demand Controlled Ventilation 42..............
Economizer Occupancy Control 43..............
Hardware 44.................................
Actuators 44................................
Supply Air Temperature Sensor 44..............
Outside Air Temperature Sensor 44.............
Enthalpy Control Sensor Configuration 44........
Operating Sequences 45........................
Staged Air Volume (3--Speed) Fan Motor 45......

2
W7220 Economizer Control 45.................
Base Unit Controls 45........................
Cooling, Unit With EconoMi$erRX
Without CO2Sensor 45........................
Heating With EconoMi$er X 47.................
Demand Controlled Ventilation 48..............
Setup and Configuration 48.....................
Initial Menu Display 48.......................
Time--out and Screensaver 48..................
Checkout 48.................................
Status 49...................................
Calibration of Sensors 49......................
Resetting All Defaults 49......................
Troubleshooting 49............................
Power Up Delay 49..........................
Power Loss (Outage or Brownout) 49............
Alarms 49..................................
Clearing Alarms 49..........................
Control Set Point and Configuration Log 52........
Staged Air Volume (SAVt)
with Variable Frequency Drive 54..................
Multi--Speed VFD Display Kit
(Field--Installed Accessory) 55....................
Connecting the Keypad to the VFD 56.............
Program the VFD for 3 Discrete Indoor Fan Speeds 57.
Smoke Detectors 64...........................
Step 13 -- Adjust Factory--Installed Options 65........
Step 14 -- Install Accessories 65...................
Step 15 -- Check Belt Tension 65...................
UNIT START--UP CHECKLIST 67..................
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical
shock or other conditions which may cause personal injury
or property damage. Consult a qualified installer, service
agency, or your distributor or branch for information or
assistance. The qualified installer or agency must use
factory--authorized kits or accessories when modifying this
product. Refer to the individual instructions packaged with
the kits or accessories when installing.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloths for brazing operations and
have a fire extinguisher available. Read these instructions
thoroughly and follow all warnings or cautions attached to
the unit. Consult local building codes and appropriate
national electrical codes (in USA, ANSI/NFPA 70,
National Electrical Code (NEC); in Canada, CSA C22.1)
for special requirements.
It is important to recognize safety information. This is the
safety--alert symbol . When you see this symbol on the
unit and in instructions or manuals, be alert to the
potential for personal injury.
Understand the signal words DANGER, WARNING,
CAUTION, and NOTE. These words are used with the
safety--alert symbol. DANGER identifies the most serious
hazards which will result in severe personal injury or
death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify
unsafe practices, which may result in minor personal
injury or product and property damage. NOTE is used to
highlight suggestions which will result in enhanced
installation, reliability, or operation.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect gas piping from unit when leak testing at
pressure greater than 0.5 psig (3450 Pa). Pressures
greater than 0.5 psig (3450 Pa) will cause gas valve
damage resulting in hazardous condition. If gas valve
is subjected to pressure greater than 0.5 psig (3450 Pa),
it must be replaced before use. When pressure testing
field--supplied gas piping at pressures of 0.5 psig
(3450 Pa) or less, a unit connected to such piping must
be isolated by closing the manual gas valve.
!WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Inlet pressure tab set screw must be tightened and 1/8in.
NPT pipe plug must be installed to prevent gas leaks.
!WARNING
GAS VALVE
INLET PRESSURE
TAP SET SCREW
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Manifold pressure tap set screw must be tightened and
1/8in. NPT pipe plug must be installed to prevent gas
leak.
!WARNING
MANIFOLD
GAS VALVE
MANIFOLD PRESSURE
TAP SET SCREW


518

3
CARBON--MONOXIDE POISONING HAZARD
Failure to follow instructions could result in severe
personal injury or death due to carbon--monoxide
poisoning, if combustion products infiltrate into the
building.
Check that all openings in the outside wall around the
vent (and air intake) pipe(s) are sealed to prevent
infiltration of combustion products into the building.
Check that furnace vent (and air intake) terminal(s)
are not obstructed in any way during all seasons.
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal
injury or death.
Before performing service or maintenance operations
on unit, always turn off main power switch to unit and
install lock(s) and lockout tag(s). Unit may have more
than one power switch.
!WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
Puronr(R--410A) refrigerant systems operate at
higher pressures than standard R--22 systems. Do not
use R--22 service equipment or components on Puron
refrigerant equipment.
!WARNING
PERSONAL INJURY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could cause personal
injury or death.
Relieve pressure and recover all refrigerant before
system repair or final unit disposal.
Wear safety glasses and gloves when handling
refrigerants. Keep torches and other ignition sources
away from refrigerants and oils.
!WARNING
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs. Use
care and wear appropriate protective clothing, safety
glasses and gloves when handling parts and servicing
air--conditioning equipment.
CAUTION
!
Rated Indoor Airflow (cfm)
This table lists the rated indoor airflow used for the AHRI
efficiency rating for the units covered in this document.
Model Number Full Load Airflow (cfm)
48LC**07 2250

4
48LCD007A1A5 -0A0 A 0
123456789
10 11 12 13 14 15 16
17 18
Model Series - WeatherExpert®
LC - Ultra High Efficiency
Unit Heat Type
48 - Gas Heat Packaged Rooftop
Cooling Tons
07 - 6 ton
Heat Options
D = Low Gas Heat
E = Medium Gas Heat
F = High Gas Heat
S = Low Heat w/ Stainless Steel Exchanger
R = Medium Heat w/ Stainless Steel Exchanger
T = High Heat w/ Stainless Steel Exchanger
Sensor Options
A = None
B = RA Smoke Detector
C = SA Smoke Detector
D = RA + SA Smoke Detector
E = CO
2
F = RA Smoke Detector and CO2
G = SA Smoke Detector and CO2
H = RA + SA Smoke Detector and CO2
Indoor Fan Options
1 = Standard Static Belt Drive with VFD controller
2 = Medium Static Belt Drive with VFD controller
3 = High Static Belt Drive with VFD controller
Refrig. Systems Options
0 = Three stage cooling capacity control with TXV
A = Three stage cooling capacity control with TXV
and Humidi-MiZer® System
Coil Options: Fin/Tube (Condenser- Evaporator - Hail Guard)
A = Al/Cu - Al/Cu
B = Precoat Al/Cu - Al/Cu
C = E-coat Al/Cu - Al/Cu
D = E-coat Al/Cu - E-coat Al/Cu
E = Cu/Cu - Al/Cu
F = Cu/Cu - Cu/Cu
M = Al/Cu -Al/Cu — Louvered Hail Guard
N = Precoat Al/Cu - Al/Cu — Louvered Hail Guard
P = E-coat Al/Cu - Al/Cu — Louvered Hail Guard
Q = E-coat Al/Cu - E-coat Al/Cu — Louvered Hail Guard
R = Cu/Cu - Al/Cu — Louvered Hail Guard
S = Cu/Cu - Cu/Cu — Louvered Hail Guard
Voltage
1 = 575/3/60
5 = 208-230/3/60
6 = 460/3/60
Design Revision
- = Factory Design Revision
Base Unit Controls
0 = Electro-mechanical Controls
1 = RTU Open Multi-Protocol Controller
4 = SystemVu™ Controller
Intake / Exhaust Options
A = None
B = Standard Leak Temperature Economizer
with Barometric Relief
E = Standard Leak Enthalpy Economizer
with Barometric Relief
N = Ultra Low Leak Temperature Economizer
with Barometric Relief
R = Ultra Low Leak Enthalpy Economizer
with Barometric Relief
Service Options
0 = None
1 = Unpowered Convenience Outlet
2 = Powered Convenience Outlet
3 = Hinged Panels
4 = Hinged Panels and
Unpowered Convenience Outlet
5 = Hinged Panels and
Powered Convenience Outlet
Packaging
0 = Standard
1 = LTL
Electrical Options
A = None
B = HACR Circuit Breaker
C = Non-Fused Disconnect
D = Thru-The-Base Connections
E = HACR Circuit Breaker
and Thru-The Base Connections
F = Non-Fused Disconnect and
Thru-The-Base Connections
Example:
Position:
a48--- 9318
Fig. 1 -- 48LC 07 Model Number Nomenclature (Example)

5
C150085
Fig. 2 -- Unit Dimensional Drawing

6
C150086
Fig. 2 -- Unit Dimensional Drawing (cont)

7
C
BA
D
C13093
LOCATION DIMENSION CONDITION
A
48---in (1219 mm)
18---in (457 mm)
18---in (457) mm
12---in (305 mm)
Unit disconnect is mounted on panel
No disconnect, convenience outlet option
Recommended service clearance
Minimum clearance
B
42---in (1067 mm)
36---in (914 mm)
Special
Surface behind servicer is grounded (e.g., metal, masonry wall)
Surface behind servicer is electrically non---conductive (e.g., wood, fiberglass)
Check sources of flue products within 10--- ft of unit fresh air intake hood
C36---in (914 mm)
18---in (457 mm)
Side condensate drain is used
Minimum clearance
D
48---in (1219 mm)
42---in (1067 mm)
36---in (914 mm)
Special
No flue discharge accessory installed, surface is combustible material
Surface behind servicer is grounded (e.g., metal, masonry wall, another unit)
Surface behind servicer is electrically non---conductive (e.g., wood, fiberglass)
Check for adjacent units or building fresh air intakes within 10---ft (3 m) of this unit’s flue outlet
NOTE: Unit not designed to have overhead obstruction. Contact Application Engineering for guidance on any application
planning overhead obstruction or for vertical clearances.
Fig. 3 -- Service Clearance Dimensional Drawing
INSTALLATION
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 for special installation
requirements.
2. Determine unit location (from project plans) or select
unit location.
3. Check for possible overhead obstructions which may
interfere with unit lifting or rigging.
Step 1 — Plan for Unit Location
Select a location for the unit and its support system (curb or
other) that provides for the minimum clearances required for
safety. This includes the clearance to combustible surfaces,
unit performance and service access below and around unit
as specified in Fig. 3.
NOTE: Consider also the effect of adjacent units.
Be sure that unit is installed such that snow will not block
the combustion intake or flue outlet.
Unit may be installed directly on wood flooring or on Class
A, B, or C roof--covering material when roof curb is used.
Do not install unit in an indoor location. Do not locate air
inlets near exhaust vents or other sources of contaminated
air. For proper unit operation, adequate combustion and
ventilation air must be provided in accordance with
Section 5.3 (Air for Combustion and Ventilation) of the
National Fuel Gas Code, ANSI Z223.1 (American
National Standards Institute) and NFPA (National Fire
Protection Association) 54 TIA----54----84----1. In Canada,
installation must be in accordance with the CAN1----B149
installation codes for gas burning appliances.

8
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto
the unit.
Locate mechanical draft system flue assembly at least 4 ft
(1.2 m) from any opening through which combustion
products could enter the building, and at least 4 ft (1.2 m)
from any adjacent building (or per local code). Locate the
flue assembly at least 10 ft (3.05 m) from an adjacent
unit’s fresh air intake hood if within 3 ft (0.91 m) of same
elevation (or per local code). When unit is located
adjacent to public walkways, flue assembly must be at
least 7 ft (2.1 m) above grade.
Select a unit mounting system that provides adequate height
to allow installation of condensate trap per requirements.
Refer to Step 11 — Install External Condensate Trap and
Line for required trap dimensions.
Roof Mount —
Check building codes for weight distribution
requirements. Unit operating weight is shown in Table 1.
Table 1 – Operating Weights
48LC**07 UNITS LB (KG)
Base Unit 1032 (468)
Economizer
Vertical 75 (34)
Horizontal 122 (55)
Powered Outlet 35 (16)
Curb
14---in/356 mm 143 (65)
24---in/610 mm 245 (111)
Step 2 — Plan for Sequence of Unit Installation
The support method used for this unit will dictate different
sequences for the steps of unit installation. For example,
on curb--mounted units, some accessories must be
installed on the unit before the unit is placed on the curb.
Review the following for recommended sequences for
installation steps.
Curb--mounted Installation —
Install curb
Install field--fabricated ductwork inside curb
Install accessory thru--base service connection package
(affects curb and unit) (refer to accessory installation
instructions for details)
Prepare bottom condensate drain connection to suit
planned condensate line routing (refer to Step 11 for
details)
Rig and place unit
Install outdoor air hood
Install flue hood
Install gas piping
Install condensate line trap and piping
Make electrical connections
Install other accessories
Pad--mounted Installation —
Prepare pad and unit supports
Check and tighten the bottom condensate drain
connection plug
Rig and place unit
Convert unit to side duct connection arrangement
Install field--fabricated ductwork at unit duct openings
Install outdoor air hood
Install flue hood
Install gas piping
Install condensate line trap and piping
Make electrical connections
Install other accessories
Frame--mounted Installation —
Frame--mounted applications generally follow the
sequence for a curb installation. Adapt as required to
suit specific installation plan.
Step 3 — Inspect Unit
Inspect unit for transportation damage. File any claim
with transportation agency.
Confirm before installation of unit that voltage, amperage
and circuit protection requirements listed on unit data
plate agree with power supply provided.
Step 4 — Provide Unit Support
Roof Curb Mount —
Accessory roof curb details and dimensions are shown in
Fig. 4. Assemble and install accessory roof curb in
accordance with instructions shipped with the curb.
NOTE: The gasketing of the unit to the roof curb is
critical for a watertight seal. Install gasket supplied with
the roof curb as shown in Fig. 4. Improperly applied
gasket can also result in air leaks and poor unit
performance.

9
7/16" [11]
4 9/16"
[115.5]
1/4"
[7.0]
"A"
1 3/4" [44.5]
1 3/4" [44.4]
20-3/4" [513] INSIDE
"A"
81 3/4"
[2076.3]
53 1/2"
[1358.9]
1 3/4" [44.5]
40 3/16" [1020.8]
2 1/4" [57.2]
26"
[660.4]
4 3/16" [106.0]
6 3/64" [153.5]
32 9/16"
[827.1]
23 1/16"
[585.8]
31 17/32"
[800.9]
1 3/4" [44.5]
15 13/16"
[401.6]
11.42" [290.0]
1 3/4"
[44.4]
3"
[76.2]
2-3/8" [61]
14 3/4" [374.7]
6' 6-1/4"
[1987.5]
1-3/4" TYP [44.5]
4' 2"
[1270.0]
15 15/32 [392.9]
1.00" [25.4]
CRBTMPWR002A01
3/4" [19] NPT 1 1/4" [31.7] NPT
CRRFCURB004A01
CONNECTOR PKG. ACC. GAS CONNECTION TYPE GAS FITTING POWER WIRING
FITTING
CONTROL WIRING
FITTING
ACCESSORY CONVENIENCE
OUTLET WIRING CONNECTOR
THRU THE CURB
1/2" [12.7] NPT 1/2" [12.7] NPT
CRBTMPWR004A01 THRU THE BOTTOM
ROOF CURB
ACCESSORY # A
CRRFCURB003A01 14"
[356]
24"
[610]
ECN NO.APP'DCHK'DBYDATEREVISION RECORDREV
1067898--MMC4/22/13
6' 61/4" WAS 6' 7 1/6", 4'2' WAS 4' 2 13/16"; 18 GA WAS 16 GA.; 15 13/16" WAS 15 15/16"; NAIL FIELD SUPPLIED WAS WITH CURB
C
DRAWING RELEASE LEVEL:
PRODUCTION
THIRD ANGLE PROJECTION
UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN INCHES
TOLERANCES ON: THIS DOCUMENT AND THE INFORMATION CONTAINED THEREIN
IS PROPRIETARY TO CARRIER CORPORATION AND SHALL NOT BE USED OR DISCLOSED TO OTHERS, IN WHOLE OR IN PART, WITHOUT THE WRITTEN AUTHORIZATION OF CARRIER CORPORATION.
1 DEC 2 DEC 3 DEC ANG
MATERIAL
----
- - -
AUTHORIZATION NUMBER TITLE
1029120
CURB ASY, ROOF
ENGINEERING MANUFACTURING
ENGINEERING REQUIREMENTS
----
SIZE DRAWING NUMBER REV
T-005, Y-002
DRAFTER CHECKER D50HJ405012 C
WEIGHT:
-MMC 12/16/09 - -
SHEET 5 OF 5
SURFACE FINISH MFG/PURCH MODEL (INTERNAL USE ONLY) NEXT DRAWING SCALE DISTRIBUTION
- PURCH - N/A -
NOTES: 1. ROOFCURB ACCESSORY IS SHIPPED DISASSEMBLED. 2. INSULATED PANELS: 25.4 [1"] THK. POLYURETHANE FOAM, 44.5 [1-3/4] # DENSITY. 3. DIMENSIONS IN [ ] ARE IN MILLIMETERS. 4. ROOFCURB: 18 GAGE STEEL. 5. ATTACH DUCTWORK TO CURB. (FLANGES OF DUCT REST ON CURB). 6. SERVICE CLEARANCE 4 FEET ON EACH SIDE. 7. DIRECTION OF AIR FLOW. 8. CONNECTOR PACKAGE CRBTMPWR002A01 IS FOR THRU-THE-CURB GAS TYPE PACKAGE CRBTMPWR004A01 IS FOR THRU-THE-BOTTOM TYPE GAS CONNECTIONS.
TYPICAL (4) SIDES
SUPPLY AIR RETURN AIR
ROOFING MATERIAL (FIELD SUPPLIED)
CANT STRIP (FIELD SUPPLIED)
ROOFING FELT (FIELD SUPPLIED)
COUNTER FLASHING (FIELD SUPPLIED)
UNIT
GASKET
(SUPPLIED WITH CURB)
RIGID INSULATION (FIELD SUPPLIED)
DUCT
(FIELD SUPPLIED)
NAIL (FIELD SUPPLIED)
CERTIFIED DRAWING
VIEW "B"
CORNER DETAIL
SECTION THRU SIDE
SEE VIEW "B"
GAS SERVICE PLATE THRU THE CURB DRILL HOLE
2" [50.8] @ ASSEMBLY (IF REQUIRED) (SEE NOTE #8)
SEE NOTE #2
12-1/2" [317.5] WIDE
INSULATED DECK PANELS
9-15/16" [252.4] WIDE
INSULATED DECK PANEL
SUPPLY AIR
RETURN AIR
SUPPLY AIR
OPENING
RETURN AIR
OPENING
C13311
Fig. 4 -- Roof Curb Details

10
Curb should be level. This is necessary for unit drain to
function properly. Unit leveling tolerances are shown in
Fig. 5. Refer to Accessory Roof Curb Installation
Instructions for additional information as required.
A-B
0.5” (13)
B-C
1.0” (25)
A-C
1.0” (25)
MAXIMUM ALLOWABLE
DIFFERENCE IN. (MM)
C06110
Fig. 5 -- Unit Leveling Tolerances
Install insulation, cant strips, roofing felt, and counter
flashing as shown. Ductwork must be attached to curb and
not to the unit. The accessory thru--the--base power and
gas connection package must be installed before the unit
is set on the roof curb. If field--installed thru--the--roof
curb gas connections are desired, use factory--supplied
1/2--in. pipe coupling and gas plate assembly to mount the
thru--the--roof curb connection to the roof curb. Gas
connections and power connections to the unit must be
field--installed after the unit is installed on the roof curb.
If electric and control wiring is to be routed through the
basepan, attach the accessory thru--the--base service
connections to the basepan in accordance with the
accessory installation instructions.
Slab Mount (Horizontal Units Only) —
Provide a level concrete slab that extends a minimum of
6 in. (150 mm) beyond unit cabinet. Install a gravel apron
in front of condenser coil air inlet to prevent grass and
foliage from obstructing airflow.
NOTE: Horizontal units may be installed on a roof curb
if required.
Alternate Unit Support
(InLieuofCurborSlabMount)—
A non--combustible sleeper rail can be used in the unit curb
support area. If sleeper rails cannot be used, support the long
sides of the unit with a minimum of 3 equally spaced 4--in. x
4--in. (102 mm x 102 mm) pads on each side.
Step 5 — Field Fabricate Ductwork
Cabinet return-air static pressure (a negative condition)
shall not exceed 0.35 in. wg (87 Pa) with economizer or
0.45 in. wg (112 Pa) without economizer.
For vertical ducted applications, secure all ducts to roof curb
and building structure. Do not connect ductwork to unit.
Fabricate supply ductwork so that the cross sectional
dimensions are equal to or greater than the unit supply
duct opening dimensions for the first 18 in. (458 mm) of
duct length from the unit basepan.
Insulate and weatherproof all external ductwork, joints,
and roof openings with counter flashing and mastic in
accordance with applicable codes.
Ducts passing through unconditioned spaces 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
applicable fire codes.
A minimum clearance is not required around ductwork.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in damage
to roofing materials.
Membrane roofs can be cut by sharp sheet metal
edges. Be careful when placing any sheet metal parts
on such roof.
CAUTION
!
Step 6 — Rig and Place Unit
Keep unit upright and do not drop. Spreader bars are
required. Rollers may be used to move unit across a roof.
Level by using unit frame as a reference. See Table 1 and
Fig. 6 for additional information.
Lifting holes are provided in base rails as shown in Fig. 6.
Refer to rigging instructions on unit.
Rigging materials under unit (cardboard or wood) must be
removed PRIOR to placing the unit on the roof curb.
When using the standard side drain connection, ensure the
red plug in the alternate bottom connection is tight. Do this
before setting the unit in place. The red plug can be
tightened with a 1/2--in. square socket drive extension. For
further details see Step 11 — Install External Condensate
Trap and Line on page 16.
Before setting the unit onto the curb, recheck gasketing on
curb.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in
equipment damage.
All panels must be in place when rigging. Unit is not
designed for handling by fork truck when packaging
is removed.
If using top crate as spreader bar, once unit is set,
carefully lower wooden crate off building roof top to
ground. Ensure that no people or obstructions are
below prior to lowering the crate.
CAUTION
!

11
ALL PANELS MUST BE IN PLACE WHEN RIGGING.
TOUS LES CAPOTS DOIVENT ÊTRE EN PLACE AVANT LE LEVAGE
CAUTION - NOTICE TO RIGGERS:
AVERTISSEMENT - REMARQUE À
L’ATTENTION DES MONTEURS
• Hook rigging shackles through holes in base rail, as shown in Detail “A”.
•Use wooden top skid, when rigging, to prevent rigging straps from damaging unit.
• Max weight includes base unit plus shipping pallet plus all available FIOP's which
could be on that size unit.
• "B" dimension is based on base unit plus economizer option only. This
dimension may vary slightly with units configured with other FIOP options.
•Spreader bars required to lift and transport the unit.
•Accrocher les manilles des élingues de levages dans les trous situés dans le rail
de base comme indiqué au Détail “A”.
• Utiliser des cales en bois lors du levage pour éviter que les élingues
n’endommagent le haut de l’appareil.
• Le poids maximum inclut la configuration de base, le poids de la palette
d'expédition, ainsi que toutes les options pouvant être installées en usine (FIOP)
pour la plateforme sélectionnée.
•La dimension de "B" provient de la configuration de base qui inclut l'option
economizer seulement, Cette dimension peut varier légèrement en fonction
des différentes options sélectionnées installées en usine (FIOP).
•Barres d'écartement requises pour soulever et transporter l'unité.
REQUIRED
“C”
“B”
“A”
914-1371
(36"-54")
SPREADER
BARS
SEE DETAIL “A”
VOIR DÉTAIL “A”
PLACE ALL SEAL STRIP IN PLACE
BEFORE PLACING UNIT ON ROOF CURB.
INSTALLER TOUTES LES BANDES
D’ISOLATION EN PLACE AVANT DE
PLACER L’APPAREIL SUR LE REBORD
DE TOIT. DUCT END
PASSAGES CONDUITES
MAX WEIGHT
LB
1145
1080
KG
520
491
IN
88
88
MM
2235
2235
IN
32
30 3/8
MM
812
772
IN
49 1/2
49 1/2
MM
1257
1257
MODEL
48LC_007
50LC_007
DETAIL A
DÉTAIL “A”
AB C
48TM504503 REV -
C13094
Fig. 6 -- Rigging Label
PositioningonCurb—
Position unit on roof curb so that the following clearances
are maintained: 1/4in. (6.4 mm) clearance between the
roof curb and the base rail inside the front and back, 0.0 in.
clearance between the roof curb and the base rail inside on
the duct end of the unit. This will result in the distance
between the roof curb and the base rail inside on the
condenser end of the unit being approximately 3--5/16 in.
(84 mm).
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
Flue vent discharge must have a minimum horizontal
clearance of 4 ft (1220 mm) from electric and gas meters,
gas regulators, and gas relief equipment. Minimum
distance between unit and other electrically live parts is
48 in. (1220 mm).
Flue gas can deteriorate building materials. Orient unit
such that flue gas will not affect building materials.
Locate mechanical draft system flue assembly at least
48 in. (1220 mm) from an adjacent building or
combustible material.
NOTE: Installation of accessory flue discharge deflector
kit will reduce the minimum clearance to combustible
material to 18 in. (460 mm).
After the unit is in position remove all riggings, shipping
materials and top skid. Recycle or dispose of all shipping
materials.
Step 7 — Convert to Horizontal and Connect
Ductwork (when required)
Unit is shipped in the vertical duct configuration. Unit
without factory--installed economizer or return air smoke
detector option may be field--converted to horizontal ducted
configuration. To convert to horizontal configuration,
remove screws from side duct opening covers and remove
covers. Using the same screws, install covers on vertical
duct openings with the insulation--side down. Seals around
duct openings must be tight. See Fig. 7.

12
C06108
Fig. 7 -- Horizontal Conversion Panels
Field--supplied flanges should be attached to horizontal
duct openings and all ductwork should be secured to the
flanges. Insulate and weatherproof all external ductwork,
joints, and roof or building openings with counter flashing
and mastic in accordance with applicable codes.
Do not cover or obscure visibility to the unit’s informative
data plate when insulating horizontal ductwork.
Step 8 — Install Outside Air Hood
Economizer Hood Package Removal and Setup --
Factory Option
1. The hood is shipped in knock--down form and must
be field assembled. The indoor coil access panel is
used as the hood top while the hood sides, divider and
filter are packaged together, attached to a metal sup-
port tray using plastic stretch wrap, and shipped in the
return air compartment behind the indoor coil access
panel. The hood assembly’s metal tray is attached to
the basepan and also attached to the damper using
two plastic tie--wraps.
2. To gain access to the hood, remove the filter access
panel. (See Fig. 8.)
FILTER
ACCESS
PANEL
INDOOR COIL
ACCESS PANEL
C13095
Fig. 8 -- Access Panel Locations
3. Locate the (2) screws holding the metal tray to the
basepan and remove. Locate and cut the (2) plastic
tie--wraps securing the assembly to the damper. (See
Fig. 9.) Be careful to not damage any wiring or cut
tie--wraps securing any wiring.
Hood Parts
Plastic Tie Wrap
Qty (2)
Screws for Metal Tray
Qty (2)
C08639
Fig. 9 -- Economizer Hood Parts Location
4. Carefully lift the hood assembly (with metal tray)
through the filter access opening and assemble per the
steps outlined in Economizer Hood, below.
Economizer Hood —
NOTE: If the power exhaust accessory is to be installed
on the unit, the hood shipped with the unit will not be
used and must be discarded. Save the aluminum filter for
use in the power exhaust hood assembly.
1. The indoor coil access panel will be used as the top of
the hood. Remove the screws along the sides and bot-
tom of the indoor coil access panel. See Fig. 10.
TOP
PANEL
INDOOR
COIL
ACCESS
PANEL
INDOOR
COIL
ACCESS
PANEL
CAULK
HERE
TOP
PANEL
C06025
Fig. 10 -- Indoor Coil Access Panel Relocation
2. Swing out indoor coil access panel and insert the
hood sides under the panel (hood top). Use the screws
provided to attach the hood sides to the hood top. Use
screws provided to attach the hood sides to the unit.
See Fig. 11.

13
B
TOP
PANEL
INDOOR COIL
ACCESS PANEL
19 1/16”
SCREW
HOOD DIVIDER
LEFT
HOOD
SIDE
33 3/8”
(848mm)
(483mm)
C06026
Fig. 11 -- Economizer Hood Construction
3. Remove the shipping tape holding the economizer
barometric relief damper in place (economizer only).
4. Insert the hood divider between the hood sides. See
Fig. 11 and 12. Secure hood divider with 2 screws on
each hood side. The hood divider is also used as the
bottom filter rack for the aluminum filter.
5. Open the filter clips which are located underneath the
hood top. Insert the aluminum filter into the bottom
filter rack (hood divider). Push the filter into position
past the open filter clips. Close the filter clips to lock
the filter into place. See Fig. 12.
6. Caulk the ends of the joint between the unit top panel
and the hood top.
7. Replace the filter access panel.
DIVIDER
BAROMETRIC
RELIEF
CLEANABLE
ALUMINUM
FILTER FILTER
HOOD
FILTER
CLIP
OUTSIDE
AIR
C08634
Fig. 12 -- Economizer Filter Installation
Step 9 — Install Flue Hood
Flue hood is shipped screwed to the basepan beside the
burner compartment access panel. Remove from shipping
location and using screws provided, install flue hood and
screen in location shown in Fig. 13.
BLOWER
ACCESS
PANEL
FLUE OPENING
C13096
Fig. 13 -- Flue Hood Details
Step 10 — Install Gas Piping
Installation of the gas piping must be accordance with
local building codes and with applicable national codes.
In U.S.A., refer to NFPA 54/ANSI Z223.1 National Fuel
Gas Code (NFGC). In Canada, installation must be
accordance with the CAN/CSA B149.1 and CAN/CSA
B149.2 installation codes for gas burning appliances.
This unit is factory equipped for use with Natural Gas fuel
at elevations up to 2000 ft (610 m) above sea level. Unit
may be field converted for operation at elevations above
2000 ft (610 m) and/or for use with liquefied petroleum
fuel. See accessory kit installation instructions regarding
these accessories.
NOTE: Furnace gas input rate on rating plate is for
installation up to 2000 ft (610 m) above sea level. In
U.S.A. the input rating for altitudes above 2000 ft (610 m)
must be derated by 4% for each 1000 ft (305 m) above sea
level.
For natural gas applications, gas pressure at unit gas
connection must not be less than 4 in. wg (996 Pa) or greater
than 13 in. wg (3240 Pa) while the unit is operating. On
48LCF/T007 (high--heat) units, the gas pressure at unit gas
connection must not be less than 5 in. wg (1245 Pa) or
greater than 13 in. wg (3240 Pa) while the unit is
operating. For liquified petroleum applications, the gas
pressure must not be less than 11 in. wg (2740 Pa) or
greater than 13.0 in. wg (3240 Pa) at the unit connection.

14
Table 2 – Natural Gas Supply Line Pressure Ranges
UNIT MODEL UNIT SIZE MIN MAX
48LCD/E/S/R0 07 4.0 in. wg
(996 Pa)
13.0 in. wg
(3240 Pa)
48LCF/T0
(High Heat units only) 07 5.0 in. wg (1245 Pa)
13.0 in. Wg
(3240 Pa)
Table 3 – Liquid Propane Supply Line Pressure Ranges
UNIT MODEL UNIT SIZE MIN MAX
48LCD/F/E/S/R/T0 07 11.0 in. wg
(2740 Pa)
13.0 in. wg
(3240 Pa)
The gas supply pipe enters the unit at the burner access
panel on the front side of the unit, through the long slot at
the bottom of the access panel. The gas connection to the
unit is made to the 3/4--in. FPT gas inlet port on the unit
gas valve.
Manifold pressure is factory--adjusted for natural gas (NG)
fuel use. Adjust as required to obtain best flame
characteristics.
Table 4 – Natural Gas Manifold Pressure Ranges
UNIT MODEL UNIT SIZE HIGH FIRE LOW FIRE
48LCD/E/S/R0 07 3.5 in. wg
(872 Pa)
1.7 in. wg
(423 Pa)
48LCF/T0
(High Heat units only) 07 3.5 in. wg (872 Pa)
2.0 in. wg
(498 Pa)
Manifold pressure for liquid propane (LP) fuel use must
be adjusted to specified range. Follow instructions in the
accessory kit to make initial readjustment.
Table 5 – Liquid Propane Manifold Pressure Ranges
UNIT MODEL UNIT SIZE HIGH FIRE LOW FIRE
48LCD/E/S/R0 07 10.0 in. wg
(2490 Pa)
5.0 in. wg
(1245 Pa)
48LCF/T0
(High Heat units only) 07 10.0 in. wg (2490 Pa)
5.7 in. wg
(1420 Pa)
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage
to equipment.
When connecting the gas line to the unit gas valve,
the installer MUST use a backup wrench to prevent
damage to the valve.
CAUTION
!
Install a gas supply line that runs to the unit heating
section. Refer to the NFPA 54/NFGC or equivalent code
for gas pipe sizing data. Do not use a pipe size smaller
than 1/2--in. Size the gas supply line to allow for a
maximum pressure drop of 0.5--in. wg (124 Pa) between
gas regulator source and unit gas valve connection when
unit is operating at high--fire flow rate.
The gas supply line can approach the unit in three ways:
horizontally from outside the unit (across the roof),
thru--curb/under unit basepan (accessory kit required) or
through unit basepan (factory--option or accessory kit
required). Consult accessory kit installation instructions
for details on these installation methods. Observe
clearance to gas line components per Fig. 14.
LEGEND
*
Field supplied.
NOTE: Follow all local codes.
NFGC – National Fuel Gas Code
STEEL PIPE
NOMINAL DIAMETER
(in.)
SPACINGOFSUPPORTS
X DIMENSION
(ft)
1/2
3/4
or 1
1
1/4
or larger
6
8
10
X
BASE UNIT
BASE RAIL
ROOF
CURB
9” MINIMUM CLEARANCE
FOR PANEL REMOVAL
MANUAL GAS
SHUTOFF VALVE
*
GAS
REGULATOR
*
48” MINIMUM
DRIP LEG
PER NFGC
*
FIELD-FABRICATED
SUPPORT
*
FROM
GAS
METER
C11091
Fig. 14 -- Gas Piping Guide
(with Accessory Thru--the--Curb Service Connections)
Factory--Option Thru--Base Connections
(Gas Connections) —
This service connection kit consists of a 3/4--in. NPT gas
adapter fitting (brass), two 1/2--in. electrical bulkhead
connectors and a 3/4--in. electrical bulkhead connector, all
factory--installed in the embossed (raised) section of the
unit basepan in the condenser section.
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
BRASS FITTING FOR 3 TO 6 TON UNITS.
C13410
Fig. 15 -- Fittings
The thru--base gas connector has male and female threads.
The male threads protrude above the basepan of the unit;
the female threads protrude below the basepan.
Check tightness of connector lock nuts before connecting
gas piping.
Install a 3/4--in NPT street elbow on the thru--base gas
fitting. Attach a 3/4--in. pipe nipple with minimum length
of 16--in. (406 mm) (field--supplied) to the street elbow
and extend it through the access panel at the gas support
bracket. See Fig. 16.

15
EMBOSSMENT BRASS FITTING
FOR 3-6 TON UNITS
SUPPORT
BRACKET
C13411
Fig. 16 -- Gas Line Piping for 6 Ton Units
Other hardware required to complete the installation of the
gas supply line will include a manual shutoff valve, a
sediment trap (drip leg) and a ground--joint union. A
pressure regulator valve may also be required (to convert gas
pressure from pounds to inches of pressure). The manual
shutoff valve must be located within 6--ft (1.83 m) of the
unit. The union, located in the final leg entering the unit,
must be located at least 9--in. (230 mm) away from the
access panel to permit the panel to be removed for service.
If a regulator valve is installed, it must be located a
minimum of 4--ft (1220 mm) away from the unit’s flue
outlet. Some municipal codes require that the manual shutoff
valve be located upstream of the sediment trap. See Fig. 17
and 18 for typical piping arrangements for gas piping that
has been routed through the sidewall of the curb. See Fig. 19
for typical piping arrangement when thru--base is used.
Ensure that all piping does not block access to the unit’s
main control box or limit the required working space in front
of the control box.
9” (229mm) min
Union
Shut Off
Valve
Drip
Leg
Thru-Curb Adapter
Unit Base Rail
C07469
Fig. 17 -- Gas Piping with Direct Drip Leg
Drip
Leg
Shut Off
Valve
Union
Thru-Curb Adapter
Burner
Access
Panel
9” (229mm) min
Unit Base Rail
C07470
Fig. 18 -- Gas Piping with Offset Drip Leg
C08018
Fig. 19 -- Gas Piping Thru--Base Connections
When installing the gas supply line, observe local codes
pertaining to gas pipe installations. Refer to the NFPA
54/ANSI Z223.1 NFGC latest edition (in Canada, CAN/CSA
B149.1). 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--in. in every 15 ft (7 mm in every 5 m) to prevent
traps. Grade all horizontal 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 appro-
priate straps, hangers, etc. Use a minimum of one
hanger every 6 ft (1.8 m). 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 lique-
fied petroleum gases as specified by local and/or nation-
al codes. If using PTFE (Teflon*) tape, ensure the mate-
rial is Double Density type and is labeled for use on gas
lines. Apply tape per manufacturer’s instructions.
*Teflon is a registered trademark of DuPont.

16
4. Pressure--test all gas piping in accordance with local
and national plumbing and gas codes before connect-
ing piping to unit.
NOTE: Pressure test the gas supply system after the gas
supply piping is connected to the gas valve. The supply
piping must be disconnected from the gas valve during the
testing of the piping systems when test pressure is in
excess of 0.5 psig (3450 Pa). Pressure test the gas supply
piping system at pressures equal to or less than 0.5 psig
(3450 Pa). The unit heating section must be isolated from
the gas piping system by closing the external main manual
shutoff valve and slightly opening the ground--joint union.
Check for gas leaks at the field--installed and
factory--installed gas lines after all piping connections
have been completed. Use soap--and--water solution (or
method specified by local codes and/or regulations).
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
SConnect gas pipe to unit using a backup wrench to
avoid damaging gas controls.
SNever purge a gas line into a combustion chamber.
SNever test for gas leaks with an open flame. Use a
commercially available soap solution made
specifically for the detection of leaks to check all
connections.
SUse proper length of pipe to avoid stress on gas
control manifold.
!WARNING
NOTE: If orifice hole appears damaged or it is suspected
to have been redrilled, check orifice hole with a numbered
drill bit of correct size. Never redrill an orifice. A
burr--free and squarely aligned orifice hole is essential for
proper flame characteristics.
BURNER
ORIFICE
A93059
Fig. 20 -- Orifice Hole
Step 11 — Install External Condensate Trap and
Line
The unit has one 3/4-in. condensate drain connection on
the end of the condensate pan and an alternate connection
on the bottom. See Fig. 21. Unit airflow configuration
does not determine which drain connection to use. Either
drain connection can be used with vertical or horizontal
applications.
To use the alternate bottom drain connection, remove the
red drain plug from the bottom connection (use a 1/2-- i n .
square socket drive extension) and install it in the side
drain connection.
The piping for the condensate drain and external trap can
be completed after the unit is in place. See Fig. 22.
DRAIN
(FACTORY-INSTALLED)
PLUG
CONDENSATE PAN (SIDE VIEW)
STANDARD
SIDE DRAIN
ALTERNATE
BOTTOM DRAIN
C08021
Fig. 21 -- Condensate Drain Pan (Side View)
NOTE: Trap should be deep enough to offset maximum unit static
difference. A 4” (102mm) trap is recommended.
MINIMUM PITCH
1” (25mm) PER
10’ (3m) OF LINE BASE RAIL
OPEN
VENT
TO ROOF
DRAIN
DRAIN PLUG
ROOF
CURB
SEE NOTE
3˝ (76mm)
MIN
C11291
Fig. 22 -- Condensate Drain Piping Details
All units must have an external trap for condensate
drainage. Install a trap at least 4-in. (102 mm) deep and
protect against freeze-up. If drain line is installed
downstream from the external trap, pitch the line away from
the unit at 1-in. per 10 ft (25 mm in 3 m) of run. Do not use
a pipe size smaller than the unit connection (3/4-in.).

17
Step 12 — Make Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Do not use gas piping as an electrical ground. 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 electrical wire connected to unit
ground lug in control compartment, or conduit
approved for electrical ground when installed in
accordance with NEC (National Electrical Code);
ANSI/NFPA 70, latest edition (in Canada, Canadian
Electrical Code CSA [Canadian Standards
Association] C22.1), and local electrical codes.
!WARNING
NOTE: Field--supplied wiring shall conform with the
limitations of minimum 63_F(33_C) rise.
Field Power Supply —
If equipped with optional Powered Convenience Outlet: The
power source leads to the convenience outlet’s transformer
primary are not factory connected. Installer must connect
these leads according to required operation of the
convenience outlet. If an always--energized convenience
outlet operation is desired, connect the source leads to the
line side of the unit--mounted disconnect. (Check with local
codes to ensure this method is acceptable in your area.) If a
de--energize via unit disconnect switch operation of the
convenience outlet is desired, connect the source leads to the
load side of the unit disconnect. On a unit without a
unit--mounted disconnect, connect the source leads to
compressor contactor C and indoor fan contactor IFC
pressure lugs with unit field power leads (see Fig. 23).
Refer to Fig. 38 for power transformer connections and the
discussion on connecting the convenience outlet on page 26.
Field power wires will be connected line--side pressure
lugs on the power terminal block or at factory--installed
option non--fused disconnect or HACR.
Field power wires are connected to the unit at line--side
pressure lugs on compressor contactor C and indoor fan
contactor IFC (see wiring diagram label for control box
component arrangement), at factory--installed option
non--fused disconnect switch or HACR. Max wire size is
#4 AWG (copper only) per pole on contactors and #2ga
AWG (copper only) per pole on optional non--fused
disconnect or HACR. See Fig. 23 and the unit label
diagram for field power wiring connections.
NOTE: TEST LEADS -- Unit may be equipped with
short leads (pigtails) on the field line connection points on
contactor C or optional disconnect switch. These leads are
for factory run--test purposes only; remove and discard
before connecting field power wires to unit connection
points. Make field power connections directly to line
connection pressure lugs only.
Disconnect
per
NEC
11 12 13
L1 L2 L3
C
208/230-3-60
460-3-60
575-3-60
Units Without Disconnect or HACR Option
Units With Disconnect or HACR Option
L1
L2
L3
2
4
6
1
5
Optional
Disconnect
Switch
Disconnect factory test leads; discard.
Factory
Wiring
3
Ground
(GR)
Equip
GR Lug
Equip GR Lug
Ground
(GR)
C13261
Fig. 23 -- Power Wiring Connections
!WARNING
FIRE HAZARD
Failure to follow this warning could result in
intermittent operation or performance satisfaction.
Do not connect aluminum wire between disconnect
switch and 48LC unit. Use only copper wire.
(See Fig. 24.)
COPPER
WIRE ONLY
ELECTRIC
DISCONNECT
SWITCH
ALUMINUM
WIRE
A93033
Fig. 24 -- Disconnect Switch and Unit

18
a48--- 9323
Fig. 25 -- 48LC 07 Electro--mechanical Control Wiring Diagram

19
a48--- 9324
Fig. 26 -- 48LC 07 RTU Open Control Wiring Diagram

20
a48--- 9318
Fig. 27 -- 48LC 07 SystemVutControl Wiring Diagram