Improper installation, adjustment, alteration, ser
vice or maintenance can cause property damage,
personal injury or loss of life. Installation and ser
vice must be performed by a licensed professional
HVAC installer or equivalent, service agency, or the
gas supplier
INSTALLATION
INSTRUCTIONS
LGH/LCH036, 048,
060 & 072
3, 4, 5 and 6 Ton
GAS AND COOLING PACKAGED UNITS
507155-01
4/2013
Supersedes 507085-01
Table Of Contents
DimensionsPage 2.................................
Parts ArrangementsPage 3.........................
Shipping and Packing ListPage 4....................
GeneralPage 4....................................
RequirementsPage 4...............................
Unit SupportPage 5................................
Duct ConnectionPage 5............................
Rigging Unit For LiftingPage 5.......................
Horizontal Air DischargePage 6......................
Condensate DrainsPage 6..........................
Gas PipingPage 8.................................
Pressure Test Gas PipingPage 9.....................
RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE
High Altitude DeratePage 9.........................
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
L
E
N
N
O
X
L
E
N
N
O
X
04/13
*2P0413*
LG SHOWN
LL
E
N
N
O
X
507155-01
*P507155-01*
LGH/LCH036, 048, 060, & 072 DIMENSIONS in. - Gas heat section shown
85−1/4 (2165)
5−5/8
11
(143)
(279)
16−1/4
(413)
18
(457)
BASE
45
(1143)
47 (1192)
BASE
END VIEW
1 (25)
AA
7 (178)
29
(737)
47 (1192)
BASE
DD
35−3/8 (899) 036 thru 048
38−7/8 (987) 036 thru 048
46−7/8 (1191) 060 thru 072
LIFTING HOLES
(For rigging)
43−3/8 (1102) 060 thru 072
3−1/2 (89)
BOTTOM
RETURN
OPENING
BOTTOM
OPENING
6−5/8
(168)
26−1/2
(673)
CONDENSATE OUTLET
CONDENSATE
OUTLET
(EITHER SIDE)
26−1/2
(673)
AIR
SUPPLY
AIR
CENTER
OF
GRAVITY
BOTTOM
TOP VIEW (Base)
83−1/4
(2115)
FLUE/VENT
OUTLET
5−1/2
(140)
SIDE VIEW
19−1/2
5 (102)
20
(508)
FF
85−1/4 (2165)
BASE
(495)
25−3/4
(654)
9−1/2
(241)
EE
BOTTOM POWER ENTRY
3 X 8 (76 X 203)
ELECTRICAL
INLET
GAS
INLET
15 (381)
27
(686)
11
18−3/8
(467)
(279)
BB
CC
1 (25)
2 (51)
38−7/8 (987) 036 thru 048
46−7/8 (1191) 060 thru 072
FORKLIFT SLOTS
(Front, Back and
Blower End)
Page 2
HORIZONTAL
SUPPLY AIR
OPENING
BACK VIEW
85−1/4 (2165)
BASE
LGH/LCH036, 048, 060, 072
20
(508)
HORIZONTAL
5−1/2
RETURN AIR
(140)
OPENING
(Without Economizer)
29
(737)
5−1/2
(140)
LGH036, 048, 060, & 072 PARTS ARRANGEMENT
FILTERS (4)
036, 048:16 X 20 X 2”
060, 072: 20 X 20 X 2”
ECONOMIZER
(OPTIONAL)
CONDENSATE
DRAIN
EVAPORATOR
L
E
N
N
O
X
L
E
N
N
O
X
COMBUSTION
AIR INDUCER
COIL
BURNERS
REHEAD COIL
(OPTIONAL)
BLOWER
GAS VALVE
TXV
(DIRECT DRIVE SHOWN)
UNIT
CONTROLLER
BLOWER
MOTOR
LL
E
N
N
O
X
COMPRESSOR
CONDENSER
FAN
COIL
GUARDS
(OPTIONAL)
CONDENSER
COIL
LCH036, 048, 060, & 072 PARTS ARRANGEMENT
REHEAT COIL
(OPTIONAL)
ELECTRIC HEAT
(Optional)
TXV
BLOWER
UNIT
CONTROLLER
FILTERS (4)
036, 048:16 X 20 X 2”
060, 072: 20 X 20 X 2”
ECONOMIZER
(OPTIONAL)
CONDENSATE
DRAIN
EVAPORATOR
COIL
L
E
N
N
O
X
L
E
N
N
O
X
BLOWER
MOTOR
(BELT DRIVE SHOWN)
LL
E
N
N
O
X
COMPRESSOR
CONDENSER
FAN
CONDENSER
COIL
LGH/LCH036, 048, 060, 072
Page 3
Shipping and Packing List
Package 1 of 1 contains:
1- Assembled unit
Check unit for shipping damage. Receiving party should
contact last carrier immediately if shipping damage is found.
General
These instructions are intended as a general guide
and do not supersede local codes in any way.
Authorities having jurisdiction should be consulted
before installation.
The LGH units are available in three heating inputs. The
LCH cooling packaged rooftop unit is the same basic
design as the LGH unit except for the heating section.
Optional electric heat is available for LCH units. LGH and
LCH units have identical refrigerant circuits with
respective 3, 4, 5, and 6 ton cooling capacities.
Units come standard with a lightweight, all-aluminum
condenser coil. Units are also available with an optional
fin/tube condenser coil.
In addition to standard heating and cooling, hot gas
reheat units provide a dehumidifying mode of operation.
Refer to Reheat Operation section.
An optional factory-installed ventilation control board
(VCB) is available. Units equipped with a VCB allow the
installer to enter the design-specified supply air and
outdoor air CFM into the Unit Controller. See VCBStart-Up section.
Availability of units and options varies by brand.
Requirements
See figure 1 for unit clearances.
WARNING
Electric shock hazard and danger of
explosion. Can cause injury, death or
product or property damage. Turn off
gas and electrical power to unit before
performing any maintenance or
servicing operations on the unit. Follow
lighting instructions attached to unit
when putting unit back into operation
and after service or maintenance.
IMPORTANT
The Clean Air Act of 1990 bans the intentional vent
ing of refrigerant (CFC's and HCFC's) as of July 1,
1992. Approved methods of recovery, recycling or
reclaiming must be followed. Fines and/or incar
ceration may be levied for non-compliance.
NOTICE
Roof Damage!
This system contains both refrigerant and oil.
Some rubber roofing material may absorb oil,
causing the rubber to swell. Bubbles in the rubber
roofing material can cause leaks. Protect the roof
surface to avoid exposure to refrigerant and oil
during service and installation. Failure to follow
this notice could result in damage to roof surface.
UNIT CLEARANCES
C
B
D
A
FIGURE 1
1
Unit
Clearance
Service
Clearance
Clearance to
Combustibles36(914)1(25)1(25)1(25)
Minimum Opera
tion Clearance36(914)36(914)36(914)36(914)
Note - Entire perimeter of unit base requires support when elevated above
mounting surface.
1
Service Clearance - Required for removal of serviceable parts.
Clearance to Combustibles - Required clearance to combustible material
(gas units).
Minimum Operation Clearance - Required clearance for proper unit operation.
Use of this unit as a construction heater or air conditioner
is not recommended during any phase of construction.
Very low return air temperatures, harmful vapors and
operation of the unit with clogged or misplaced filters will
damage the unit.
If this unit has been used for heating or cooling of
buildings or structures under construction, the following
conditions must be met or the warranty will be void:
A room thermostat must control the unit. The use of
fixed jumpers that will provide continuous heating or
cooling is not allowed.
A pre-filter must be installed at the entry to the return
air duct.
The return air duct must be provided and sealed to
the unit.
Return air temperature range between 55°F (13°C)
and 80°F (27°C) must be maintained.
Page 4
A
in.(mm)Bin.(mm)Cin.(mm)Din.(mm)
48
(1219)36(914)36(914)36(914)
LGH/LCH036, 048, 060, 072
To p
Clearance
Unob
structed
Unob
structed
Unob
structed
Air filters must be replaced and pre-filters must be
removed upon construction completion.
The input rate and temperature rise must be set per
the unit rating plate.
The heat exchanger, components, duct system, air
filters and evaporator coil must be thoroughly
cleaned following final construction clean-up.
The unit operating conditions (including airflow,
cooling operation, ignition, input rate, temperature
rise and venting) must be verified according to these
installation instructions.
Unit Support
In downflow discharge installations, install the unit on a
non-combustible surface only. Unit may be installed on
combustible surfaces when used in horizontal discharge
applications or in downflow discharge applications when
installed on an T1CURB / C1CURB / E1CURB roof
mounting frame.
NOTE - Securely fasten roof frame to roof per local codes.
A-Downflow Discharge Application
Roof Mounting with T1CURB / C1CURB / E1CURB
1- The roof mounting frame must be installed, flashed
and sealed in accordance with the instructions
provided with the frame.
2- The roof mounting frame should be square and level
to 1/16” per linear foot (5mm per linear meter) in any
direction.
5- Units require support along all four sides of unit base.
Supports must be constructed of steel or suitably
treated wood materials.
NOTE-When installing a unit on a combustible surface for
downflow discharge applications, a T1CURB / C1CURB /
E1CURB roof mounting frame is required.
B-Horizontal Discharge Applications
1- Units which are equipped with an optional
economizer and installed in horizontal airflow
applications must use a horizontal conversion kit.
2- Specified installation clearances must be maintained
when installing units. Refer to figure 1.
3- Top of support slab should be approximately 4”
(102mm) above the finished grade and located so no
run-off water from higher ground can collect around
the unit.
4- Units require support along all four sides of unit base.
Supports must be constructed of steel or suitably
treated wood materials.
Duct Connection
All exterior ducts, joints and openings in roof or building
walls must be insulated and weather-proofed with
flashing and sealing compounds in accordance with
applicable codes. Any duct passing through an
unconditioned space must be insulated.
3- Duct must be attached to the roof mounting frame
and not to the unit; supply and return plenums must
be installed before setting the unit.
Installer's Roof Mounting Frame
Many types of roof frames can be used to install the unit
depending upon different roof structures. Items to keep
in mind when using the building frame or supports are:
1- The base is fully enclosed and insulated, so an
enclosed frame is not required.
2- The frames or supports must be constructed with
non-combustible materials and should be square and
level to 1/16” per linear foot (5mm per linear meter)
in any direction.
3- Frame or supports must be high enough to prevent
any form of moisture from entering unit.
Recommended minimum frame height is 14”
(356mm).
4- Duct must be attached to the roof mounting frame
and not to the unit. Supply and return plenums must
be installed before setting the unit.
LGH/LCH036, 048, 060, 072
CAUTION
In downflow applications, do not drill or punch
holes in base of unit. Leaking in roof may occur if
unit base is punctured.
Rigging Unit For Lifting
Rig unit for lifting by attaching four cables to holes in unit
base rail. See figure 2.
1- Detach wooden base protection before rigging.
2- Remove all six base protection brackets before
setting unit.
3- Connect rigging to the unit base using both holes in
each corner.
4- All panels must be in place for rigging.
5- Place field‐provided H‐style pick in place just above
top edge of unit. Frame must be of adequate
strength and length. (H-style pick prevents damage
to unit.)
Page 5
Unit
LG
LC
*Maximum weight with all available
factory-installed accessories.
LIFTING POINT SHOULD
BE DIRECTLY ABOVE
CENTER OF GRAVITY
*Weight
Lbs. Kg.
435
960
423
933
IMPORTANT - ALL
PANELS MUST
BE IN PLACE
FOR RIGGING.
5- Install return air duct beneath outdoor air intake. See
figure 4. Install barometric relief damper in lower
hood and install in ductwork as shown in figure 4.
HORIZONTAL RETURN AIR DUCTWORK
WITH ECONOMIZER
UNITUNIT
HORIZONTAL
RETURN AIR
DUCT
CAUTION - Do
not walk on unit.
FIGURE 2
Horizontal Air Discharge
Unit is shipped with panels covering the horizontal supply
and return air openings. Remove horizontal covers and
place over downflow openings for horizontal air discharge.
See figure 3. Secure in place with sheet metal screws.
Units Equipped With An Optional Economizer
1- Remove the horizontal supply air cover and position
over the downflow supply air opening. Secure with
sheet metal screws.
2- Leave the horizontal return air cover in place.
3- Locate the separately ordered horizontal air
discharge kit. Place the kit panel over the downflow
return air opening.
4- Remove and retain the barometric relief dampers and
lower hood.
UNIT SUPPLY AND RETURN AIR OPENINGS
HORIZONTAL
HORIZONTAL
RETURN AIR
OPENING
SUPPLY AIR
OPENING
INSTALL BAROMETRIC RELIEF DAMPERS
AND HOOD IN RETURN AIR DUCT
FIGURE 4
Condensate Drains
Make drain connection to the drain coupling provided on
unit. Older model units have a 3/4” N.P.T. coupling and
newer model units have a 1” N.P.T. coupling.
Note - The drain pan is made with a glass reinforced
engineered plastic capable of withstanding typical joint
torque but can be damaged with excessive force. Tighten
pipe nipple hand tight and turn an additional quarter turn.
A trap must be installed between drain connection and an
open vent for proper condensate removal. See figure 5 or
6. It is sometimes acceptable to drain condensate onto
the roof or grade; however, a tee should be fitted to the
trap to direct condensate downward. The condensate line
must be vented. Check local codes concerning
condensate disposal. Refer to pages 1 and 2 for
condensate drain location.
CONDENSATE SIDE DRAIN CONNECTION
CAULK AROUND CONDENSATE COUPLING
NOTE - Allow clearance to
open doors when installing
condensate piping.
Minimum Pitch
1” (25 mm) per
10' (3 m) of line
OPEN VENT
UNIT
DOWNFLOW
RETURN AIR
OPENING
DOWNFLOW
SUPPLY AIR
FIGURE 3
MOUNTING
FRAME
OPENING
FIGURE 5
Page 6
LGH/LCH036, 048, 060, 072
CONDENSATE BOTTOM DRAIN CONNECTION
2- Lift the front edge of the drain pan and slide pan out
of unit. See figure 9.
UNIT
DRAIN PAN
CAULK AROUND
CONDENSATE COUPLING
OPEN VENT
MOUNTING
FRAME
Minimum Pitch
1” (25 mm) per 10'
(3 m) of line
FIGURE 6
Units are shipped with the drain coupling facing the front
of the unit. Condensate can be drained from the back or
bottom of the unit with the following modifications. The
unit can be installed in either downflow or horizontal air
discharge regardless of condensate drain location.
Rear Drain Connection
1- Remove the condensate drain mullion. See figure 7.
Remove the two panels on each side of the mullion.
REMOVE DRAIN PAN
DRAIN PAN
FIGURE 9
3- Make sure the cap over the unit bottom drain hole is
secure.
4- Rotate the drain pan until the downward slope is
toward the back of the unit. Slide the drain pan back
into the unit. Be careful not to dislodge the cap over
the bottom drain hole.
5- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
6- Replace the condensate drain mullion.
Bottom Drain Connection
CONDENSATE
DRAIN MULLION
FIGURE 7
Two hinge screws must be removed in addition to the
mullion screws. See figure 8.
UNITS WITH HINGED PANELS
CONDENSATE
DRAIN MULLION
REMOVE
TWO
SCREWS
FIGURE 8
1- Remove the condensate drain mullion. See figure 7.
2- Lift the front edge of the drain pan and slide pan out
of unit. See figure 9.
3- Turn the drain pan upside down and drill a pilot hole
through the bottom of the drain pan in the center of
the coupling. See figure 10.
BOTTOM CONDENSATE DRAIN
CAUTION: Be careful not to
damage the coupling threads
when drilling the hole.
After drilling the pilot
hole, drill a 7/8” hole from
the inside of the pan.
DRILL A PILOT
HOLE IN CENTER
OF COUPLING
FIGURE 10
LGH/LCH036, 048, 060, 072
Page 7
®
4- From the inside of the pan, use a Vari-Bit
bit to
enlarge the hole to 7/8”. Do not damage coupling
threads.
5- Remove the cap over the unit bottom drain hole.
6- Slide the drain pan back into the unit.
7- From the back side of the unit, pull the drain pan
coupling through the rear condensate opening.
8- From the front side of the unit, move the drain pan
until the bottom coupling settles into the unit bottom
drain opening. Once in place, check to make sure the
coupling is still positioned through the rear
condensate drain hole.
9- Use a field-provided 3/4” plug to seal side drain
connection.
10- Replace the condensate drain mullion.
CAUTION
If a flexible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe
shall be installed at the gas valve and extend out
side the furnace cabinet.
WARNING
Do not exceed 600 in-lbs (50 ft.-lbs) torque when at
taching the gas piping to the gas valve.
IMPORTANT
Connect Gas Piping (Gas Units)
Before connecting field-provided piping, check with gas
company or authorities having jurisdiction for local code
requirements. When installing gas supply piping, length
of run from gas meter must be considered in determining
pipe size for 0.5” w.c. (.12kPa) maximum pressure drop.
Do not use supply pipe smaller than unit gas connection.
Operating pressures at the unit gas connection must be
as shown in table 1.
TABLE 1
OPERATING PRESSURE AT GAS CONNECTION “w.c.
Natural GasLP / Propane Gas
Min.Max.Min.Max.
036-0724.510.51113
When making piping connections a drip leg should be
installed on vertical pipe runs to serve as a trap for
sediment or condensate. A 1/8” N.P.T. plugged tap is
located on gas valve for test gauge connection. Refer to
Heating Start-Up section for tap location. Install a ground
joint union between the gas control manifold and the
main manual shut-off valve. See figure 11 for gas supply
piping entering outside the unit. Figure 12 shows
complete bottom gas entry piping.
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquified petroleum gases.
Do not use Teflon® tape to seal gas piping. Use a
moderate amount of pipe compound on the gas pipe only.
Make sure the two end threads are bare.
Compounds used on threaded joints of gas piping
must be resistant to the actions of liquified petro
leum gases.
OUTSIDE OF UNIT GAS PIPE CONNECTION
TO GAS
VALV E
GROUND
JOINT UNION
TO GAS
SUPPLY
GAS PIPING
SUPPORT
MANUAL MAIN
SHUT-OFF VALVE
DRIP LEG
(REFER TO
LOCAL CODES)
FIGURE 11
Page 8
LGH/LCH036, 048, 060, 072
BOTTOM ENTRY GAS PIPING COMPLETED
power to unit. These devices should be properly labeled
by the installer.
GROUND
JOINT UNION
STREET
ELBOW
7” NIPPLE
2-1/2” NIPPLE
DRIP LEG
Grommets for both gas pipe openings are field provided.
TO GAS
VALV E
TO GAS
SUPPLY
MANUAL MAIN
SHUT-OFF VALVE
FIGURE 12
Pressure Test Gas Piping (Gas Units)
When pressure testing gas lines, the gas valve must
be disconnected and isolated. Gas valves can be
damaged if subjected to more than 0.5 psig (3.48kPa).
See figure 13.
NOTE-Codes may require that manual main shut-off
valve and union (furnished by installer) be installed in
gas line external to unit. Union must be of the ground
joint type.
PRESSURE TEST GAS LINE
MANUAL MAIN
SHUT-OFF VALVE
GAS VALVE
CAP
FIGURE 13
High Altitude Derate
Locate the high altitude conversion sticker in the unit
literature bag. Fill out the conversion sticker and affix next
to the unit nameplate.
Refer to table 2 for high altitude adjustments.
TABLE 2
HIGH ALTITUDE DERATE
Altitude Ft.*Gas Manifold Pressure
2000-4500See Unit Nameplate
4500 And AboveDerate 2% / 1000 Ft. Above Sea Level
After all connections have been made, check all piping
connections for gas leaks. Also check existing unit gas
connections up to the gas valve; loosening may occur
during installation. Use a leak detection solution or other
preferred means. Do not use matches candles or other
sources of ignition to check for gas leaks.
CAUTION
Some soaps used for leak detection are corrosive
to certain metals. Carefully rinse piping thoroughly
after leak test has been completed. Do not use
matches, candles, flame or othe sources of ignition
to check for gas leaks.
WARNING
Danger of explosion. Can cause injury
or product or property damage. Do not
use matches, candles, flame or other
sources of ignition to check for leaks.
NOTE-In case emergency shut down is required, turn off
the main manual shut-off valve and disconnect main
LGH/LCH036, 048, 060, 072
*Units installed at 0-2000 feet do not need to be modified.
NOTE ‐ This is the only permissible derate for these units.
Electrical Connections
POWER SUPPLY
Do not apply power or close disconnect switch until
installation is complete. Refer to start-up directions.
Refer closely to unit wiring diagram.
Refer to unit nameplate for minimum circuit ampacity
and maximum fuse size.
1- Units are factory-wired for 230,460,575 volt supply.
For 208V supply
cover from the 208V terminal on the control
transformer. Move the wire from the transformer
240V terminal to the 208V terminal. Place the
insulated terminal cover on the unused 240V
terminal.
2- Route power through the bottom power entry area
and connect to L1, L2, and L3 on the top of K1 in
control area above compressor. Secure power
wiring with factory-installed wire ties provided in
Page 9
, remove the insulated terminal
control box. Route power to TB2 on units equipped
with electric heat. Route power to S48 or CB10 If
unit is equipped with the optional disconnect
switch or circuit breaker. See unit wiring diagram.
3- Solar-Ready Units Only -
All solar-ready units are equipped with an S48 circuit
breaker and F54 solar fuse block. Connect power
wiring to the top of S48. Connect solar module wiring
to the pigtails provided on the bottom of F54. Solar
equipment must be specified for use with this unit.
CONTROL WIRING
CAUTION
Electrostatic discharge can affect electronic com
ponents. Take precautions during unit installation
and service to protect the electronic controls. Pre
cautions will help to avoid control exposure to elec
trostatic discharge by putting the unit, the control
and the technician at the same electrostatic poten
tial. Neutralize electrostatic charge by touching
hands and all tools on an unpainted unit surface,
such as the gas valve or blower deck, before per
forming any service procedure.
A-Thermostat Location
Room thermostat mounts vertically on a standard 2” X 4”
handy box or on any non-conductive flat surface.
Locate thermostat approximately 5 feet (1524mm)
above the floor in an area with good air circulation at
average temperature. Avoid locating the room
thermostat where it might be affected by:
-drafts or dead spots behind doors and in corners
-hot or cold air from ducts
-radiant heat from sun or appliances
-concealed pipes and chimneys
B-Control Wiring
The Unit Controller will operate the unit from a
thermostat or zone sensor based on the System Mode.
The default System Mode is the thermostat mode. Refer
to the Unit Controller Installation and Setup Guide to
change the System Mode. Use the menu navigation
arrows and select button; see Settings - Install.
Thermostat Mode
1- Route thermostat cable or wires from subbase to
control area above compressor (refer to unit
dimensions to locate bottom and side power entry).
IMPORTANT - Unless field thermostat wires are rated
for maximum unit voltage, they must be routed away
from line voltage wiring. Use wire ties located near the
lower left corner of the controls hat section to secure
thermostat cable.
Use18 AWG wire for all applications using remotely
installed electro-mechanical and electronic
thermostats.
2- Install thermostat assembly in accordance with
instructions provided with thermostat.
3- Connect thermostat wiring to Unit Controller on the
lower side of the controls hat section.
4- Wire as shown in figure 14 for electro-mechanical
and electronic thermostats. If using other
temperature control devices or energy management
systems see instructions and wiring diagram
provided by manufacturer.
IMPORTANT-Terminal connections at the wall plate or
subbase must be made securely. Loose control wire
connections may allow unit to operate but not with proper
response to room demand.
Zone Sensor Mode
The Unit Controller will operate heating and cooling
based on the Unit Controller internal setpoints and the
temperature from the A2 zone sensor. An optional
Network Control Panel (NCP) can also be used to provide
setpoints. A thermostat or return air sensor can be used
as a back-up mode. Make zone sensor wiring
connections as shown in figure 15.
Page 10
LGH/LCH036, 048, 060, 072
FIELD WIRING WITH ELECTRONIC AND ELECTRO-MECHANICAL THERMOSTATS
24 V POWER
TO M2 THERMOSTAT INPUTS
R
C
G
B
K55
A
TO PROVIDE SUPERMARKET REHEAT SCHEME
USE S86 DEHUMIDISTAT AND K55.
W1
W2
Y1
Y2
OCP
2
2
K55−1
S86
ALLOTHERTHERMOSTAT
SIGNALS REMAIN CONNECTED
AS SHOWN ON THE RIGHT.
TO R
7
TO G
5
TO Y1
(Thermostat Mode)
R
C
G
W1
W2
Y1
2
Y2
OCP
FIGURE 14
J297A
B
C
10
P297
1
A55
P262
10
J262C
2
11
3
4
5
W1
W2
12
6
7
8
9
FIELD WIRING IN ZONE SENSOR MODE
(Zone Sensor Mode)
UNIT CONTROLLER
24VAC
RC
SENSOR
IAQ
AI1
SENSOR
HUM
TMP
OUTPUTS
D01
D02
J298
A2 SENSOR
FIGURE 15
C-Hot Gas Reheat Units Only -
1- Install humidity sensor in accordance with
instructions provided with sensor. A DDC input may
be used to initiate dehumidification instead of a
sensor.
2- Make wiring connections as shown in figure 14 for
Thermostat Mode or figure 15 for Zone Sensor
Mode. In addition, connect either a humidity
sensor or a dehumidification input. See figure 16
or 17 for humidity sensor wiring or figure 18 for
dehumidification input wiring.
Humidity Sensor Cable Applications:
Wire runs of 50 feet (mm) or less:
Use two separate shielded cables containing 20AWG
minimum, twisted pair conductors with overall shield.
Belden type 8762 or 88760 (plenum) or equivalent.
Connect both cable shield drain wires to TB1-7 as shown
in figure 16.
Wire runs of 150 feet (mm) or less:
Use two separate shielded cables containing 18AWG
minimum, twisted pair conductors with overall shield.
Belden type 8760 or 88760 (plenum) or equivalent.
Connect both cable shield drain wires to TB1-7 as shown
in figure 16.
Wire runs over 150 feet (mm):
Use a local, isolated 24VAC transformer such as Lennox
cat #18M13 (20VA minimum) to supply power to RH
sensor as shown in figure 17. Use two shielded cables
containing 20AWG minimum, twisted pair conductors
with overall shield. Belden type 8762 or 88760 (plenum)
or equivalent.
LGH/LCH036, 048, 060, 072
Page 11
FIELD WIRING REHEAT UNITS (Using A Humidity
Sensor With Less Than 150 Ft. Wire Runs)
P298
1
2
B
3
4
C
5
6
7
D
8
9
10
R
C
AI−1
HUM
TMP
DO−1
C
DO−2
DI−1
1011
12
P262
J262B
56
A91
VIN
VO
GND
J298A
2
FIGURE 16
FIELD WIRING REHEAT UNITS (Using A Humidity
Sensor With More than 150 Ft. Wire Runs)
NOT
CONNECTED
A91
VIN
GND
VO
ISOLATED 24V
TRANSFORMER
DRAIN
NOT
CONNECTED
J298A
A55 UNIT
CONTROLLER
P298
1
2
B
3
4
C
5
6
7
D
8
9
10
R
C
AI-1
HUM
TMP
DO-1
C
DO-2
DI-1
FIGURE 17
FIELD WIRING REHEAT UNITS
(Using A Dehumidification Switch)
J299
R
DI−4
C
DEHUMIDIFICATION
SWITCH
Use 24 VAC (R) from any terminal
available on J299−2, −5, or −7.
7
8
9
10
FIGURE 18
Page 12
Blower Operation and Adjustments
Three-, four- and five-ton units are equipped with either
direct drive or multi-pole belt drive blowers. 6-ton units
are available with belt drive blowers only.
IMPORTANT
Three phase scroll compressors must be phased
sequentially for correct compressor and blower
rotation. Follow “COOLING START-UP” section of
installation instructions to ensure proper compres
sor and blower operation.
A-Blower Operation
Refer to the Unit Controller Installation and Setup Guide
to energize blower. Use the menu navigation arrows and
select button; see Service - Test.
B-Determining Unit CFM
1- The following measurements must be made with air
filters in place.
IMPORTANT - On units equipped with direct drive
blowers, determine and adjust high speed CFM before
low speed CFM. Low speed CFM should be adjusted to
2/3 of high speed CFM. A low speed adjustment less than
2/3 of high speed will improve humidity removal; refer to
product data for more information.
2- With all access panels in place, measure static
pressure external to unit (from supply to return).
Blower performance data is based on static pressure
readings taken in locations shown in figure 19.
Note - Static pressure readings can vary if not taken
where shown.
3- Measure the indoor blower wheel RPM.
4- Referring to Page 16 through Page 26, use static
pressure and RPM readings to determine unit CFM.
Use Page 27 when installing units with any of the
options or accessories listed. Refer to table 3 for
minimum airflow when electric heat is installed.
TABLE 3
MINIMUM AIRFLOW-LC UNITS WITH ELECTRIC HEAT
(BELT DRIVE)
Kw
LCH036HE
LCH048HE
LCH060HE
Downflow & Horizontal Airflow
LGH/LCH036, 048, 060, 072
CFM
1080
1280
1600
LOCATION OF STATIC PRESSURE READINGS
INSTALLATIONS WITH DUCTWORK
INSTALLATIONS WITH CEILING DIFFUSERS
ROOFTOP UNIT
RETURN AIR
READING LOCATION
SUPPLY
MAIN
DUCT RUN
RE
TURN
FIRST BRANCH
OFF OF MAIN RUN
SUPPLY AIR
READING
LOCATION
ECTO SETTINGS
Unit Controller “SET
TINGS-CONTROL-MSAV”
Menu
SMOKE SPEED0.02558059
HIGH SPEED0.04558059
ECTO
LGH/LCH Unit Factory Settings
036
048
060
H4E
H4E
H4E
SUPPLY AIR
LOCATION
FIGURE 19
TABLE 4
036-060
S4T
Not Applica
ble
Not Applica
ble
ROOFTOP UNIT
SUPPLY
READING
Field SettingDescription
DIFFUSER
% torque for indoor blower smoke
speed.
% torque for indoor blower high
speed.
RE
TURN
RETURN AIR
READING
LOCATION
060
H4E
Not Applica
ble
036-060
S4T
Not Applica
ble
Field SettingDescription
LOW SPEED0.05284036
Unit Controller “SET
TINGS-SETPOINTSDAMPER” Menu
MIN OCP BLOWER LOW0.09151515
MIN OCP BLOWER HIGH5.2410101010
Installer: Circle applicable unit model number and record any ECTO changes under “Field Setting” column. Settings need to be recorded by
installer for use when unit controller is replaced or reprogrammed. Refer to unit controller guide “Setting” menu path or use optional software to
change settings.
ECTO
LGH/LCH Unit Factory Settings
036
048
H4E
H4E
C-Adjusting Unit CFM - Direct Drive Blowers
The supply CFM can be adjusted by changing Unit
Controller settings; see Settings - Control - MSAV menu.
Refer to table 4. Adjustments can also be made by using
optional software. Record any CFM changes on the
MINIMUM AND MAXIMUM PULLEY ADJUSTMENT
BeltMin. Turns OpenMaxi. Turns Open
A SectionNo minimum5
% torque for indoor blower low
speed.
Damper minimum position during
low indoor blower.
Damper minimum position during
high indoor blower.
TABLE 5
ECTO Settings label located on the inside of the
compressor access panel.
D-Adjusting Unit CFM - Belt Drive Blowers
The blower RPM can be adjusted at the motor pulley.
Loosen Allen screw and turn adjustable pulley clockwise
to increase CFM. Turn counterclockwise to decrease
CFM. See figure 20. Do not exceed minimum and
maximum number of pulley turns as shown in table 5.
E-Blower Belt Adjustment - Belt Drive
Maximum life and wear can be obtained from belts only
if proper pulley alignment and belt tension are
maintained. Tension new belts after a 24-48 hour
period of operation. This will allow belt to stretch and
seat grooves. Make sure blower and motor pulley are
aligned as shown in figure 21.
Page 13
LGH/LCH036, 048, 060, 072
TO INCREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE
BLOWER ASSEMBLY
TO DECREASE CFM
TURN PULLEY
COUNTERCLOCKWISE
SIDE VIEW
MOTOR
TO INCREASE BELT TENSION
1-Loosen four bolts securing motor base to mounting
frame.
2-Slide the motor downward to tighten the belt.
3-Tighten four bolts on motor base.
ALLEN
SCREW
PULLEY
FIGURE 20
1- Loosen four bolts securing motor base to mounting
frame. See figure 20.
2- To increase belt tension -
Slide blower motor downward to tighten the belt. This
increases the distance between the blower motor and
the blower housing.
3- To loosen belt tension -
Slide blower motor upward to loosen the belt. This
decreases the distance between the blower motor
and the blower housing.
LOOSEN ALLEN
SCREW TO
ADJUST CFM
LOOSEN FOUR BOLTS AND
SLIDE BLOWER MOTOR
DOWNWARD TO TIGHTEN BELT
3- Remove the screw from the back side of the bracket.
4- Move the tensioner to the appropriate adjustment
hole and reinstall screw.
5- Replace bracket.
6- Replace blower belt. See figure 24.
G-Check Belt Tension
Overtensioning belts shortens belt and bearing life.
Check belt tension as follows:
1- Measure span length X. See figure 22.
4- Tighten four bolts securing motor base to the
mounting frame.
PULLEY ALIGNMENT
ALIGNED
MOTOR
PULLEY
BELT
NOT ALIGNED
BLOWER
PULLEY
FIGURE 21
F-Blower Belt Adjustment - Units Equipped With An
Optional Belt Tensioner
1- Remove blower belt.
2- Remove bracket from blower housing. See figure 23.
MEASURE BELT TENSION
FORCE
DEFLECTION 1/64” PER INCH OF SPAN
OR 1.5mm PER 100mm OF SPAN
FIGURE 22
2- Apply perpendicular force to center of span (X) with
enough pressure to deflect belt 1/64” for every inch
of span length or 1.5mm per 100mm of span length.
Example: Deflection distance of a 40” span would be
40/64” or 5/8”.
Example: Deflection distance of a 400mm span
would be 6mm.
Page 14
LGH/LCH036, 048, 060, 072
3- Measure belt deflection force. For a used belt, the
deflection force should be 5 lbs. (35kPa). A new belt
deflection force should be 7 lbs. (48kPa).
A force below these values indicates an
undertensioned belt. A force above these values
indicates an overtensioned belt.
H-Field-Furnished Blower Drives
For field-furnished blower drives, use page 19 through 26
to determine BHP and RPM required. Reference Page 27
to determine the drive kit number. Reference table 6 for
manufacturer's drive numbers.
Includes tension assembly, Fenner no. FS0590; OEM no. 101994-02
5- Refer to Cooling Operation and Adjustment section for
proper method to check refrigerant charge.
A-Operation
1- Initiate first and second stage cooling demands
according to instructions provided with Unit
Controller Installation and Setup Guide. Use the
menu navigation arrows and select button; see
Service - Test.
2- No Economizer Installed in Unit -
A first-stage cooling demand (Y1) will energize the
compressor and blower in low speed along with the
condenser fan. An increased cooling demand (Y2)
will increase the blower and compressor to high
speed.
Units Equipped With Economizer -
When outdoor air is acceptable, a first-stage
cooling demand (Y1) will energize the economizer.
An increased cooling demand (Y2) will energize
the compressor and low speed blower along with
the condenser fan. When outdoor air is not
acceptable unit will operate as though no
economizer is installed.
3- Units contain one refrigerant circuit or stage.
4- Unit is charged with R-410A refrigerant. See unit
rating plate for correct amount of charge.
B-Three Phase Scroll Compressor Voltage Phasing
Three phase scroll compressors must be phased
sequentially to ensure correct compressor and blower
rotation and operation. Compressor and blower are
wired in phase at the factory. Power wires are
color-coded as follows: line 1-red, line 2-yellow, line
3-blue.
1- Observe suction and discharge pressures and
blower rotation on unit start-up.
2- Suction pressure must drop, discharge pressure
must rise, and blower rotation must match rotation
marking.
If pressure differential is not observed or blower rotation is
not correct:
3- Disconnect all remote electrical power supplies.
4- Reverse any two field-installed wires connected to
the line side of K1 contactor. Do not reverse wires at
blower contactor.
5- Make sure the connections are tight.
Discharge and suction pressures should operate at
their normal start‐up ranges.
Page 28
LGH/LCH036, 048, 060, 072
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