Carrier WeatherExpert 48LC User manual

Installation Instructions
48LC
WeatherExpertRSeries
Single Package Rooftop
Gas Heat/Electric Cooling Unit
with Puronr(R---410A) Refrigerant
Sizes: 14, 17, 20, 24, 26
NOTE: Read the entire instruction manual before starting
the installation.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 2....................
Rated Indoor Airflow (cfm) 4.....................
INSTALLATION 15..............................
Jobsite Survey 15...............................
Step 1 -- Plan for Unit Location 15.................
Roof Mount 15..............................
Step 2 -- Plan for Sequence of Unit Installation 15.....
Curb--Mounted Installation 15..................
Pad--Mounted Installation 15...................
Frame--Mounted Installation 15.................
Step 3 -- Inspect Unit 15..........................
Step 4 -- Provide Unit Support 16..................
Roof Curb Mount 16.........................
Slab Mount (Horizontal Units Only) 16..........
Alternate Unit Support
(In Lieu of Curb or Slab Mount) 16.............
Step 5 -- Field Fabricate Ductwork 20...............
Step 6 -- Rig and Place Unit 20....................
Positioning on Curb 21.......................
Step 7 -- Horizontal Duct Connection 21............
Step 8 -- Install Outside Air Hood — Factory Option 21..
Step 9 -- Install Flue Hood and Combustion Air Hood 22.
Step 10 -- Install Gas Piping 23....................
Gas Supply Line 23..........................
Factory--Option Thru--Base Connections 24.......
Step 11 -- Install External Condensate Trap and Line 25..
Step 12 -- Make Electrical Connections 25...........
Field Power Supply 25........................
Units Without Factory--Installed
Non--Fused Disconnect or HACR 32.............
Units With Factory--Installed
Non--Fused Disconnect or HACR 32.............
All Units 33................................
Convenience Outlets 33.......................
HACR 34..................................
Factory--Option Thru--Base Connections 35......
Units Without Thru--Base Connections 35........
Field Control Wiring 35.......................
Thermostat 35...............................
Unit Without Thru--Base Conversion Kit 35.......
Heat Anticipator Settings 36...................
Transformer Connection
for 208--v Power Supply 36.....................
RTU Open Controller (Factory--Installed Option) 36...
SystemVutController (Factory--Installed Option) 36..
Humidi--MiZerRSystem Control Connections 37....
Humidi--MiZer System -- Space RH Controller 37..
Integrated Staging Control (ISC) Board 38...........
ISC Board — Sequence of Operation 38...........
General 38.................................
Ventilation 38...............................
Cooling 39.................................
Humidi--MiZer System (Optional) 39............
Economizer (Optional) 39.....................
Low Ambient Cooling Operation
Down to 40_F(4_C) 40.......................
Heating 40.................................
EconoMi$erRX (Factory--Installed Option) 41.......
Unit Installation 41..........................
Enthalpy Sensor Relocation 41.................
W7220 Economizer Controller 41................
User Interface 41............................
Keypad 41.................................
Menu Structure 42.............................
Connections and Applications 46.................
W7220 Economizer Module Wiring 46..........
Economizer Controlled Configurations 47..........
Enthalpy Changeover Control 47...............
Enthalpy Settings 47.........................
Demand Controlled Ventilation 49..............
Economizer Occupancy Control 50..............

2
Hardware 51.................................
Actuators 51................................
Supply Air Temperature Sensor 51..............
Outside Air Temperature Sensor 51.............
Enthalpy Control Sensor Configuration 51........
Operating Sequences 52........................
Staged Air Volume (3--Speed) Fan Motor 52......
W7220 Economizer Control 52.................
Base Unit Controls 52........................
Cooling, Unit With EconoMi$erRX
Without CO2Sensor 52.......................
Heating With EconoMi$er X 54.................
Demand Controlled Ventilation 55..............
Setup and Configuration 55.....................
Initial Menu Display 55.......................
Time--out and Screensaver 55..................
Checkout 55.................................
Status 56...................................
Calibration of Sensors 56......................
Resetting All Defaults 56......................
Troubleshooting 56............................
Power Up Delay 56..........................
Power Loss (Outage or Brownout) 56............
Alarms 56..................................
Clearing Alarms 56..........................
Control Set Point and Configuration Log 59........
Staged Air Volume (SAVt)
with Variable Frequency Drive 62..................
Multi--Speed VFD Display Kit
(Field--Installed Accessory) 63....................
Connecting the Keypad to the VFD 63.............
Program the VFD for 3 Discrete
Indoor Fan Speeds 64..........................
Smoke Detectors 80...........................
Return Air Sensor Tube Installation 80...........
Smoke Detector Test Magnet 80................
Additional Application Data 80.................
Step 13 -- Install Accessories 80...................
Step 14 -- Check Belt Tension 81...................
UNIT START--UP CHECKLIST 83..................
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

518

3
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
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.
Ware 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
!

518

4
Rated Indoor Airflow (cfm)
The table to the right 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**14 4375
48LC**17 4875
48LC**20 5690
48LC**24 6500
48LC**26 7500
48LCD024A1A5-0A0 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
14 - 12.5 ton
17 - 15 ton
20 - 17.5 ton
24 - 20 ton
26 - 23 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 = CO2
F = RA Smoke Detector and CO
2
G = SA Smoke Detector and CO
2
H = RA + SA Smoke Detector and CO
2
Indoor Fan Motor Options
1 = Standard Static / Vertical Supply, Return Air Flow
2 = Medium Static / Vertical Supply, Return Air Flow
3 = High Static / Vertical Supply, Return Air Flow
4 = Ultra High Static / Vertical Supply, Return Air Flow
5 = Standard Static / Horizontal Supply, Return Air Flow
6 = Medium Static / Horizontal Supply, Return Air Flow
7 = High Static / Horizontal Supply, Return Air Flow
8 = Ultra High Static / Horizontal Supply, Return Air Flow
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 = Temperature Standard Leak Economizer with
Barometric Relief
C = Temperature Standard Leak Economizer with
Centrifugal Power Exhaust - Vertical Only
E = Enthalpy Standard Leak Economizer with
Barometric Relief
F = Enthalpy Standard Leak Economizer with
Centrifugal Power Exhaust - Vertical Only
N = Temperature Ultra Low Leak Economizer with
Barometric Relief
P = Temperature Ultra Low Leak Economizer
with Centrifugal Power Exhaust - Vertical Only
R = Enthalpy Ultra Low Leak Economizer with
Barometric Relief
S = Enthalpy Ultra Low Leak Economizer with
Centrifugal Power Exhaust - Vertical Only
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
Example:
Position:
a48--- 9335
Fig. 1 -- 48LC 14--26 Model Number Nomenclature (Example)

5
C13057
Fig. 2 -- Unit Dimensional Drawing – 14 Size Unit, Sheet 1 of 3

6
C13058
Fig.2(cont)--UnitDimensionalDrawing–14SizeUnit,Sheet2of3

7
C13059
Fig.2(cont)--UnitDimensionalDrawing–14SizeUnit,Sheet3of3

8
C13032
Fig. 3 -- Unit Dimensional Drawing – 17 and 20 Size Units, Sheet 1 of 3

9
C13033
Fig. 3 (cont) -- Unit Dimensional Drawing – 17 and 20 Size Units, Sheet 2 of 3

10
C13034
Fig. 3 (cont) -- Unit Dimensional Drawing – 17 and 20 Size Units, Sheet 3 of 3

11
C14106
Fig. 4 -- Unit Dimensional Drawing – 24 and 26 Size Units, Sheet 1 of 3

12
C14107
Fig. 4 (cont) -- Unit Dimensional Drawing – 24 and 26 Size Units, Sheet 2 of 3

13
C14108
Fig. 4 (cont) -- Unit Dimensional Drawing – 24 and 26 Size Units, Sheet 3 of 3

14
C
B
D
A
C12384
LOCATION DIMENSION CONDITION
A36---in (914 mm) • Recommended clearance for air flow and service
B42---in (1067 mm) • Recommended clearance for air flow and service
C
18---in (457 mm)
• No Convenience Outlet
•NoEconomizer
• No field--- installed disconnect on economizer hood side (Factory ---installed disconnect installed).
36---in (914 mm) • Convenience Outlet installed.
• Vertical surface behind servicer is electrically non---conductive (e.g.: wood, fiberglass).
42---in (1067 mm) • Convenience Outlet installed.
• Vertical surface behind servicer is electrically conductive (e.g.: metal, masonry).
96---in (2438 mm) • Economizer and/or Power Exhaust installed.
• Check for sources of flue products with 10 feet (3 meters) of economizer fresh air intake.
D42---in (1067 mm) • Recommended clearance for service.
NOTE: Unit not designed to have overhead obstruction. Contact Application Engineering for guidance on any application planning
overhead obstruction or for vertical clearances.
Fig. 5 -- Service Clearance Dimensional Drawing
Table 1 – Operating Weights
48LC** UNIT LB (KG)
14 17 20 24 26
Base Unit 1853 (842.3) 2095 (952.3) 2201 (1000.7) 2347 (1067.0) 2492 (1132.6)
Economizer 246 (112) 246 (112) 246 (112) 246 (112) 246 (112)
Powered Outlet 35 (16) 35 (16) 35 (16) 35 (16) 35 (16)
Curb
14---in/356 mm 240 (109) 240 (109) 255 (116) 255 (116) 273 (124)
24---in/610 mm 340 (154) 340 (154) 355 (161) 355 (161) 355 (161)

15
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 installa-
tion 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, around and
above unit as specified in unit drawings. See Fig. 5.
NOTE: Consider also the effect of adjacent units.
Be sure that the unit is installed such that snow will not
block the combustion air intake or flute 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.
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.
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 thru--base service connection fittings (affects
curb and unit)
Rig and place unit
Remove top skid
Install outside air hood
Install smoke detector tube
Install combustion 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
Rig and place unit
Remove duct covers and top skid
Install smoke detector return air sensor tube
Install field--fabricated ductwork at unit duct openings
Install outside air hood
Install combustion 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.
On units with hinged panel option, check to be sure all
latches are tight and in closed position.
Locate the carton containing the outside air hood parts; see
Fig. 7 and 13. Do not remove carton until unit has been
rigged and located in final position.

16
Step 4 — Provide Unit Support
Roof Curb Mount —
Accessory roof curb details and dimensions are shown in
Fig. 8, 9 and 10. 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. 8, 9 and 10. Improperly applied
gasket can also result in air leaks and poor unit performance.
Curb should be level. This is necessary for unit drain to
function properly. Unit leveling tolerances are shown in
Fig. 6. Refer to Accessory Roof Curb Installation
Instructions for additional information as required.
A-B
0.25” (6)
B-C
0.5” (12)
A-C
0.5” (12)
MAXIMUM ALLOWABLE
DIFFERENCE IN. (MM)
A
B
C
C10628
Fig. 6 -- 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. Thru--the--base power connection must be
installed before the unit is set on the roof curb. If
field--installed thru--the--roof curb gas connections are
desired, remove knockout in basepan located in the gas
section; see Fig. 7 for location. 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, remove knockouts in basepan located in control
box area of access panel; see Fig. 2, 3, or 4 for basepan
knockout locations for location. Attach the service
connections to the basepan.
Control Box
A
ccess Panel
Filter and
Indoor Coil
Access Panel
Indoor Blower
Access Panel
Gas Heat
Access Panel Compressor
(each side)
Hood Carton Location
(rear access panel)
C11154
Fig. 7 -- Typical Access Panel and Compressor Locations
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 (In Lieu of Curb or Slab
Mount) —
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 4 equally
spaced 4--in. x 4--in. (102 mm x 102 mm) pads on each
side. Locate pads so that they support the rails. Make sure
to avoid the fork openings.

17
C13054
Fig. 8 -- Roof Curb Details – 14 Size Unit

18
C13055
Fig. 9 -- Roof Curb Details – 17 and 20 Size Units

19
C13056
Fig. 10 -- Roof Curb Details – 24 and 26 Size Units

20
Step 5 — Field Fabricate Ductwork
Cabinet return-air static pressure (a negative condition)
shall not exceed 0.5 in. wg (87 Pa) with economizer or
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 not
required if top crating is left on unit. Rollers may be used
to move unit across a roof. Level by using unit frame as a
reference. See Table 1 (on page 14) and Fig. 11 (below)
for additional information.
Lifting holes are provided in base rails as shown in
Fig. 11. Refer to rigging instructions on unit.
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.
CAUTION
!
Before setting the unit onto the curb, recheck gasketing on
curb.
"B"
"C"
"A"
"914-1371"
(36"-54")
DETAIL A
SEE DETAIL A
PLACE ALL SEAL STRIP
IN PLACE BEFORE PLACING
UNIT ON ROOF CURB.
DUCT END
C09107
UNIT MAX WEIGHT DIMENSIONS
A B C
LB KG IN MM IN MM IN MM
48LC**14 2135 970 127.8 3249 59.1 1501 52.3 1328
48LC**17 2377 1080 141.5 3595 65.5 1664 60.3 1532
48LC**20 2483 1129 141.5 3595 65.5 1664 60.3 1532
48LC**24 2629 1195 157.8 4007 72.8 1849 60.3 1532
48LC**26 2774 1261 157.8 4007 7208 1849 60.3 1532
NOTES:
1. Dimensions in ( ) are inches.
2. Hook rigging shackles through holes in base rail, as shown in detail “A.” Holes in base rails are centered around the unit center of
gravity. Use wooden top to prevent rigging straps from damaging unit.
Fig. 11 -- Rigging Details