Lennox LGA Series Installation and operation manual

ã1998 LennoxIndustriesInc.
Litho U.S.A.
Page 1
Corp.9822-L12
LGA/LCA
Service Literature
3.0to6.0TON
10.5to21 kW
Revised 09/2001
LGA/LCA SERIES
TheLGA/LCA3,3.5,4,5and6ton(10.5,12.3,14,17.5and
21 kW)unitsareconfigureto orderunits(CTO)with a wide
selection of factoryinstalled options.The
LGA/042/048/060/072 gas/electricpackaged rooftop units
areavailablein78,000,92,000or125,000Btuh(22.85,27,or
36.6kW)heating inputs,withthe LGA036 available onlyin
78,000 heating input. Gasheatsectionsare designed with
Lennox’aluminized oroptionalstainless steeltube heatex-
changers.The LCAcooling packaged rooftop unitsare
equipped withthe samecooling sectionsasthe LGAunits.
Optionalelectricheatisfactory-orfield-installed in LCAunits.
Electricheatoperatesinsingle ormultiplestagesdepending
onthekWinputsize.7.0kWthrough30kWheatsectionsare
available.LGAand LCAunitshaveidenticalrefrigerantcir-
cuitswith 3,3.5,4,5 and 6 ton (10.5,12.3,14,17.5 and 21
kW)cooling capacities.LGA/LCAunitsutilize onecompres-
sor.
The LGAand LCAunitsare designed to acceptanyofsev-
eraldifferentenergymanagement thermostatcontrolsys-
temswithminimumfieldwiring.Factoryorfield provided
controloptions connect tothe unitwithjack plugs.When
”plugged in”the controlsbecome an integralpartof the unit
wiring.
Information contained inthismanual isintended foruse by
qualified servicetechniciansonly.Allspecificationsaresub-
ject tochange.Proceduresoutlined inthismanualare pre-
sented asarecommendation onlyand do notsupersede or
replacelocalorstatecodes.
If theunitmustbeliftedforservice,rig unitby attaching
fourcables totheholes locatedintheunitbase rail (two
holes ateachcorner).Refertotheinstallation instruc-
tionsfortheproper rigging technique.
Electric shock hazard.Cancause
injuryordeath.Before attempting to
performany service ormaintenance,
turnthe electricalpowerto unitOFF at
disconnectswitch(es).Unitmay have
multiplepowersupplies.
WARNING
!
LGA060 (5TON)SHOWN
LCA060 (5TON)SHOWN
Библиотека СОК 

Page 2
TABLEOFCONTENTS
Introduction Page 1...........................
SpecificationsPages3-4......................
ElectricalDataPages5-7......................
ElectricalHeatAccessoriesDataPage 8.........
BlowerDataPages9-11.......................
PartsArrangementPage 12....................
I-UNITCOMPONENTSPages14-32.............
ControlBoxComponentsPages14-16..........
Cooling ComponentsPages17-19..............
BlowerCompartmentPages19-22..............
GasHeatComponentsPages23-27............
ElectricHeatDataPages28-30.................
ElectricHeatComponentsPages31-32..........
II-PLACEMENTAND INSTALLATIONPage 33.....
III-CHARGINGPages33-34.....................
NormalOperating PressuresPages33-34.......
IV-STARTUP-OPERATIONPage 35-36............
Preliminaryand SeasonalChecks Page 35.......
Cooling Startup Page 35.......................
Heating Startup Page 36-37....................
SafetyorEmergency ShutdownPage 37.......
V-SYSTEMS SERVICECHECKSPages37-40.....
LGAHeating ServiceChecks Pages37-40.......
High Altitude Page 38.........................
Cooling ServiceChecks Page 40...............
VI-MAINTENANCEPages40......................
FiltersPage 40...............................
Lubrication Page 40..........................
SupplyAirBlowerWheelPage 40...............
Evaporatorand CondenserCoil Page 40.........
ElectricalPage 40............................
VII-ACCESSORIES Pages41-44...................
LARMFRoofMounting FramesPage 41.........
TransitionsPage 41...........................
Supplyand ReturnDiffusersPage 42............
LAOAD(M)OutdoorAirDampersPage 42........
LAREMDEconomizersPages42-43............
LAGED(H)GravityExhaustDampersPage 43....
LAPEFPowerExhaustFansPage 43...........
OptionalColdWeatherKitPages43-44..........
ControlSystemsPage 44......................
SmokeDetectorsPage 44.....................
BlowerProving SwitchPage 44.................
DirtyFilterSwitchPage 44.....................
IndoorAirQualitySensorPage 44..............
LP/Propane KitPage 44......................
VIII-WIRINGDIAGRAMS/OPERATIONSEQUENCE
LGA/LCA036/072 Pages45-48..............
LGA036/072 Pages49-50.....................
ThermostatPages51.........................
EconomizerPage 52..........................
ElectricHeatPages53-54.....................

Page 3
SPECIFICATIONS3-4TON
ModelNo.LCA/LGA036 LCA/LGA042 LCA/LGA048
Cooling Efficiency type StandardHigh StandardHigh StandardHigh
Gross Cooling Capacity—Btuh (kW)38,000 (11.1)38,000 (11.1)44,200 (12.9)44,500 (13.0)50,500 (14.8)50,200 (14.7)
C
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i
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g
R
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t
i
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g
s
¡NetCooling Capacity—Btuh (kW)36,000 (10.6)35,800 (10.5)42,000 (12.3)42,500 (12.5)48,000 (14.1)48,000 (14.1)
C
o
o
l
i
n
g
RatingsTotalUnitPower (kW)3.9 3.4 4.6 4.0 5.0 4.6
R
a
t
i
n
g
s
¡SEER(Btuh/Watt)10.0 12.0 10.0 12.0 10.0 12.0
EER(Btuh/Watt)9.2 10.5 9.1 10.6 9.6 10.4
©Sound Rating Number (db)82
RefrigerantCharge Furnished (HCFC-22)6lbs.10 oz.
(3.01 kg)8lbs.6 oz. (3.80 kg)6lbs.10 oz. (3.01 kg)8lbs.13 oz. (4.00 kg)7lbs.9 oz. (3.43 kg)9lbs.8 oz. (4.31 kg)
L
G
A
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s
O
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y
ModelNo.LGA036 LGA042 LGA048
L
G
A
M
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d
e
l
s
Only
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t
a
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e
Heat InputType StandardStandardDualorHigh StandardDualorHigh
T
w
o
S
t
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e
Heating
C
a
p
a
c
i
t
y
Input(low)—Btuh (kW) ---- ---- 92,000 (27.0) ---- 92,000 (27.0)
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e
a
t
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g
Capacity
(
N
a
t
u
r
a
l
o
r
Output(low)—Btuh (kW) ---- ---- 72,700 (21.3) ---- 72,700 (21.3)
(
N
a
t
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r
a
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r
L
P
G
/
P
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p
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e
Input(High)—Btuh (kW)78,000 (22.9)78,000 (22.9)125,000 (36.6)78,000 (22.9)125,000 (36.6)
L
P
G
/
P
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e
Gas(atSea
L
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v
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l
)
Output(High)—Btuh (kW)61,600 (18.1)61,600 (18.1)98,750 (29.0)61,600 (18.1)98,750 (29.0)
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a
s
(
a
t
S
e
a
Level)A.G.A./C.G.A.ThermalEfficiency /AFUE80.0%/78.0%
GasSupplyConnectionsnpt—in.-NaturalorLPG/Propane 1/2
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c
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m
m
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—
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.
(
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)
Natural7(1.7)
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G
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Pressure—wc.in.(kPa)LPG/Propane 11 (2.7)
Blowerwheelnomi-
naldia.xwidth—in.(mm)11-1/2X9(292 X229)
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c
t
D
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M
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NominalMotoroutputhp (W).75 (560)
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c
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D
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MotorVoltage &phase 208/230v-1ph or3 ph or460v,575v-3ph
1
.
5
h
p
M
o
t
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r
o
u
t
p
u
t
h
p
(
k
W
)
Nominal1.5(1.1)
1
.
5
h
p
(
1
.
1
k
W
)
M
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&
M
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o
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p
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hp(kW)Max.usable 1.72 (1.3)
E
v
a
p
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r
a
t
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r
(
1
.
1
k
W
)
¢Motor&
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s
Voltage &phase 208/230v-1ph,208/230v,460vor575v-3ph
E
v
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a
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B
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r
¢
M
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&
Drives(Drivekit#)RPMrange (1)615 -920 or (2)800-1105
B
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and Drive
S
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c
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i
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2
h
p
M
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p
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h
p
(
k
W
)
Nominal2(1.5)
a
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D
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Selection
2
h
p
(
1
.
5
k
W
)
M
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&
M
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r
o
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p
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t
hp (kW)Max.usable 2.3(1.7)
(
1
.
5
k
W
)
¢Motor&
D
r
i
v
e
s
Voltage &phase 208/230v,460vor575v-3ph
¢
M
o
t
o
r
&
Drives(Drivekit#)RPMrange (3)920 -1230
3
h
p
M
o
t
o
r
o
u
t
p
u
t
h
p
(
k
W
)
Nominal3(2.2)
3
h
p
(2.2kW)
M
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&
M
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o
r
o
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p
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t
hp (kW)Max.usable 3.45 (2.6)
(
2
.
2
k
W
)
¢Motor&
D
r
i
v
e
s
Voltage &phase 208/230v,460vor575v-3ph
¢
M
o
t
o
r
&
Drives(Drivekit#)RPMrange (4)1070 -1325
Net face area —sq. ft. (m2)6.25 (0.58)
Tube diameter—in.(mm)&No.ofrows3/8(9.5) - 2 3/8(9.5) - 3 3/8(9.5) - 2 3/8(9.5) - 3
Evaporator
C
o
i
l
Finsperinch(m)15 (591)
E
v
a
p
o
r
a
t
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r
Coil Drainconnection no.&size-in.(mm)
fpt(1)3/4(19)
Expansion devicetype Balanced PortThermostaticExpansion Valve,removeable powerhead
C
o
n
d
e
n
s
e
r
Net face area —sq. ft. (m2)14.6(1.35)
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n
s
e
r
C
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l
Tube diameter—in.(mm)&No.ofrows3/8(9.5) - 1.3 3/8(9.5) - 2 3/8(9.5) - 1.3 3/8(9.5) - 2
C
o
i
l
Finsperinch(m)20 (787)
Diameter—in.(mm)&No.ofblades24 (610) - 3
C
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n
d
e
n
s
e
r
TotalAirvolume—cfm(L/s)4000 (1890)4200 (1980)
C
o
n
d
e
n
s
e
r
F
a
n
s
Motorhorsepower (W)1/3(224)
F
a
n
s
Motor rpm1075
TotalMotorwatts320 360
F
i
l
t
e
r
s
(
f
u
r
n
i
s
h
e
d
)
Type of filterDisposableCommercialGrade Pleated
F
i
l
t
e
r
s
(furnished)No.and size—in.(mm) (2)16 x25 x2(406 x635 x51)
Electricalcharacteristics 208/203v-—60 hertz—1 phase
208/230v,460vor575v—60 hertz—3 phase
¡Rated in accordancewithARIStandard 210/240 and certified toARI; 95_F(35_C)outdoorairtemperature and 80_F(27_C)db/67_F(19_C)wb entering evaporatorair;mini-
mumexternalductstaticpressure.
©Sound Rating Number rated in accordancewithtestconditionsincluded inARIStandard 270.
¢Using totalairvolume and systemstaticpressurerequirementsdetermine fromblowerperformancetablesrpmand motoroutputrequired.Maximumusable outputofmotors
furnished byLennoxareshown. InCanada,nominalmotoroutputisalsomaximumusablemotoroutput. If motorsofcomparable outputare used,be suretokeep withinthe
servicefactorlimitationsoutlined on the motornameplate.
NOTE—Netcapacityincludesevaporatorblower motorheatdeduction. Gross capacitydoesnotinclude evaporatorblower motorheatdeduction.

Page 4
SPECIFICATIONS5-6TON
ModelNo.LCA/LGA060 LCA/LGA072
Cooling Efficiency Type StandardHigh StandardHigh
Gross Cooling Capacity—Btuh (kW)60,500 (17.7)63,000 (18.5)76,000 (22.3)74,500 (21.8)
C
o
o
l
i
n
g
¡NetCooling Capacity—Btuh (kW)57,500 (16.9)60,000 (17.6)72,000 (21.1)71,500 (21.0)
C
o
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l
i
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g
RatingsTotalUnitPower (kW)6.5 5.8 7.6 6.85
R
a
t
i
n
g
s
¡SEER(Btuh/Watt)10.0 12.0---- ----
EER(Btuh/Watt)8.8 10.3 9.0 10.5
©Sound Rating Number (db)82
RefrigerantCharge Furnished (HCFC-22)7lbs.14 oz.
(3.57 kg)10 lbs.0 oz. (4.54 kg)9lbs.5 oz. (4.22 kg)9lbs.13 oz. (4.45 kg)
L
G
A
M
o
d
e
l
s
ModelNo.LGA060 LGA072
LGAModels
O
n
l
y
T
w
o
S
t
a
g
e
Heat InputType StandardDualorHigh StandardDualorHigh
O
n
l
y
TwoStage
H
e
a
t
i
n
g
C
a
p
a
c
i
t
y
Input(low)—Btuh (kW) ---- 92,000 (27.0) ---- 92,000 (27.0)
T
w
o
S
t
a
g
e
H
e
a
t
i
n
g
C
a
p
a
c
i
t
y
(
N
a
t
u
r
a
l
o
r
Output(low)—Btuh (kW) ---- 72,700 (21.3) ---- 72,700 (21.3)
(
N
a
t
u
r
a
l
o
r
LPG/Propane
G
a
s
Input(High)—Btuh (kW)78,000 (22.9)125,000 (36.6)78,000 (22.9)125,000 (36.6)
L
P
G
/
P
r
o
p
a
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e
Gas
(
a
t
S
e
a
L
e
v
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l
)
Output(High)—Btuh (kW)61,600 (18.1)98,750 (28.9)61,600 (18.1)98,750 (28.9)
(
a
t
S
e
a
L
e
v
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l
)
A.G.A./C.G.A.ThermalEfficiency /AFUE80.0%/78.0%
GasSupplyConnectionsnpt—in.-NaturalorLPG/Propane 1/2
R
e
c
o
m
m
e
n
d
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d
G
a
s
S
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P
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—
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c
.
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.
(
k
P
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)
Natural7
R
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m
m
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n
d
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d
G
a
s
SupplyPressure—wc.in.(kPa)LPG/Propane 11
Blowerwheelnominaldia.xwidth—in.(mm)11-1/2x9(292 x229)
D
i
r
e
c
t
D
r
i
v
e
M
o
t
o
r
Nominalmotoroutput—hp (kW).75 (.56) ----
D
i
r
e
c
t
D
r
i
v
e
MotorVoltage &phase 208/230v-1 or3ph or460,575v-3ph ----
1
.
5
h
p
(
1
.
1
k
W
)
Nominalmotorhorsepower (kW)1.5(1.1)
1.5hp(1.1kW)
¢
M
o
t
o
r
&
Max.usablemotoroutput—hp (kW)1.72 (1.3)
¢
M
o
t
o
r
&
D
r
i
v
e
s
Voltage &phase 208/230v-1ph,208/230v,460vor575v-3ph
Evaporator
B
l
o
w
e
r
D
r
i
v
e
s
(Drivekit#)RPMrange (1)615 -920 or (2)800 -1105
E
v
a
p
o
r
a
t
o
r
Blower
a
n
d
2
h
p
(
1
.
5
k
W
)
Nominalmotoroutput—hp (kW)2(1.5)
a
n
d
DriveSelection 2hp(1.5kW)
¢
M
o
t
o
r
&
Max.usablemotoroutput—hp (kW)2.3(1.7)
D
r
i
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e
S
e
l
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c
t
i
o
n
¢
M
o
t
o
r
&
D
r
i
v
e
s
Voltage &phase 208/230v,460vor575v-3ph
D
r
i
v
e
s
(Drivekit#)RPMrange (3)920 -1230
3
h
p
(
2
.
2
k
W
)
Nominalmotorhorsepower (kW)3(2.2)
3hp(2.2kW)
¢
M
o
t
o
r
&
Max.usablemotoroutput—hp (kW)3.45 (2.6)
¢
M
o
t
o
r
&
D
r
i
v
e
s
Voltage &phase 208/230v,460vor575v-3ph
D
r
i
v
e
s
(Drivekit#)RPMrange (4)1070 -1325
Net face area —sq. ft. (m2)6.25 (0.58)
Tube diameter—in.(mm)&No.ofrows3/8(9.5)—2 3/8(9.5)—3 3/8(9.5)—3 3/8(9.5)—4
EvaporatorCoil Finsperinch(m)15 (591)
E
v
a
p
o
r
a
t
o
r
C
o
i
l
Drainconnection no.&size—in.(mm)fpt(1)3/4(19)
Expansion devicetype Balanced PortThermostaticExpansion Valve,removeable powerhead
Net face area —sq. ft. (m2)14.6(1.35)
CondenserCoil Tube diameter—in.(mm)&No.ofrows3/8(9.5)—2
C
o
n
d
e
n
s
e
r
C
o
i
l
Finsperinch(m)20 (788)
Diameter—in.(mm)&No.ofblades24 —3
C
o
n
d
e
n
s
e
r
TotalAirvolume—cfm(L/s)4200
Condenser
F
a
n
s
Motorhorsepower (W)1/3(248)
F
a
n
s
Motor rpm1075
TotalMotorwatts360
F
i
l
t
e
r
s
(
f
u
r
n
i
s
h
e
d
)
Type of filterDisposableCommercialGrade Pleated
F
i
l
t
e
r
s
(furnished)No.and size—in.(mm) (2)16 x25 x2(406 x635 x51)
Electricalcharacteristics 208/203v-—60 hertz—1 phase
208/230v,460vor575v
60 hertz—3 phase208/230v,460vor575v
60 hertz—3 phase
¡Rated in accordancewithARIStandard 210/240 and certified toARI; 95_F(35_C)outdoorairtemperature and 80_F(27_C)db/67_F(19_C)wb entering evaporatorair;mini-
mumexternalductstaticpressure.
©Sound Rating Number rated in accordancewithtestconditionsincluded inARIStandard 270.
¢Using totalairvolume and systemstaticpressurerequirementsdetermine fromblowerperformancetablesrpmand motoroutputrequired.Maximumusable outputofmotors
furnished byLennoxareshown. InCanada,nominalmotoroutputisalsomaximumusablemotoroutput. If motorsofcomparable outputare used,be suretokeep withinthe
servicefactorlimitationsoutlined on the motornameplate.
NOTE—Netcapacityincludesevaporatorblower motorheatdeduction. Gross capacitydoesnotinclude evaporatorblower motorheatdeduction.

Page 5
ELECTRICALDATA3-31/2TON
ModelNo.LCA/LGA036
Line voltage data—60 Hz208/230v-
1 phase208/230v- 3 phase460v 3 phase575v 3 phase
O
u
t
d
o
o
r
F
a
n
M
o
t
o
r
Full load amps2.4 1.3 1.0
O
u
t
d
o
o
r
Fan MotorLocked rotoramps4.7 2.4 1.9
I
n
d
o
o
r
M
o
t
o
r
O
u
t
p
u
t
hp 0.75 1.5 0.75 1.5 2 3 0.75 1.5 2 3 0.75 1.5 2 3
Indoor
B
l
o
w
e
r
M
o
t
o
r
OutputkW0.56 1.1 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2
B
l
o
w
e
r
M
o
t
o
r
Full load amps4.6 11.5 4.6 5.7 7.5 10.6 2.3 2.8 3.4 4.8 2.3 2.4 2.7 3.9
M
o
t
o
r
Locked rotoramps10 55 10 40 46.9 66 5.4 20 20.4 26.8 5.4 15 16.2 23.4
O
p
t
i
o
n
a
l
P
o
w
e
r
Horsepower (W)1/2(363)
OptionalPower
E
x
h
a
u
s
t
F
a
n
Full load amps4.4 1.7
E
x
h
a
u
s
t
F
a
n
Locked rotoramps4.7 4.1
ServiceOutlet(2)115 voltGFCI(amprating)15
LCA/LGA036SMODELS
C
o
m
p
r
e
s
s
o
r
Rated load amps14.8 10.6 4.8 4.2
C
o
m
p
r
e
s
s
o
r
Locked rotoramps78.8 65.1 32.8 26.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 45 50 35 35 35 40 15 15 15 15 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 40 45 30 30 30 35 15 15 15 15 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 30 37 25 26 28 31 12 12 13 14 11 11 11 12
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 26 33 21 22 24 27 10 11 11 13 9 9 9 11
LCA/LGA036HMODELS
C
o
m
p
r
e
s
s
o
r
Rated load amps12.4 10.3 5.8 4.2
C
o
m
p
r
e
s
s
o
r
Locked rotoramps88.0 77.0 39.0 30.6
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 35 45 30 35 35 40 15 15 20 20 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 35 40 30 30 30 35 15 15 15 20 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 27 34 25 26 28 31 13 14 14 16 11 11 11 12
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 23 30 20 21 23 26 11 12 12 14 9 9 9 11
ModelNo.LCA/LGA042
Line voltage data—60 Hz208/230v
1 phase208/230v 3 phase460v 3 phase575v 3 phase
O
u
t
d
o
o
r
F
a
n
M
o
t
o
r
Full load amps2.4 1.3 1.0
O
u
t
d
o
o
r
Fan MotorLocked rotoramps4.7 2.4 1.9
I
n
d
o
o
r
M
o
t
o
r
O
u
t
p
u
t
hp 0.75 1.5 0.75 1.5 2 3 0.75 1.5 2 3 0.75 1.5 2 3
Indoor
B
l
o
w
e
r
M
o
t
o
r
OutputkW0.56 1.1 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2
B
l
o
w
e
r
M
o
t
o
r
Full load amps4.6 11.5 4.6 5.7 7.5 10.6 2.3 2.8 3.4 4.8 2.3 2.4 2.7 3.9
M
o
t
o
r
Locked rotoramps10.1 55 10 40 46.9 66 5.4 20 20.4 26.8 5.4 15 16.2 23.4
O
p
t
i
o
n
a
l
P
o
w
e
r
Horsepower (W)1/2(363)
OptionalPower
E
x
h
a
u
s
t
F
a
n
Full load amps4.4 1.7
E
x
h
a
u
s
t
F
a
n
Locked rotoramps4.7 4.1
ServiceOutlet(2)115 voltGFCI(amprating)15
LCA/LGA042SMODELS
C
o
m
p
r
e
s
s
o
r
Rated load amps18.0 11.4 5.8 5.0
C
o
m
p
r
e
s
s
o
r
Locked rotoramps92.0 84.0 42.0 35.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 50 50 35 35 40 40 15 15 15 20 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 45 50 30 30 35 35 15 15 15 15 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 34 41 26 27 29 32 13 14 14 16 12 12 12 13
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 30 37 22 23 25 28 11 12 12 14 10 10 10 12
LCA/LGA042HMODELS
C
o
m
p
r
e
s
s
o
r
Rated load amps17.9 12.4 5.8 4.8
C
o
m
p
r
e
s
s
o
r
Locked rotoramps104.0 88.0 44.0 34.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 50 50 35 40 40 45 15 15 20 20 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 45 50 35 35 35 40 15 15 15 15 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 34 41 27 29 30 33 13 14 14 16 12 12 12 13
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 30 37 23 24 26 29 11 12 12 14 10 10 10 11
*RefertoNationalorCanadian Electrical Code manualto determine wire, fuse and disconnectsizerequirements.
NOTE—Extremesofoperating range are plusand minus10 %ofline voltage.
NOTE—Wherecurrentdoesnotexceed 100 amps,HACR type circuitbreaker maybe used in place of fuse(U.S.only).

Page 6
ELECTRICALDATA4-5TON
ModelNo.LCA/LGA048
Line voltage data—60 Hz208/230v
1 phase208/230v 3 phase460v 3 phase575v 3 phase
O
u
t
d
o
o
r
F
a
n
M
o
t
o
r
Full load amps2.4 1.3 1.0
O
u
t
d
o
o
r
Fan MotorLocked rotoramps4.7 2.4 1.9
I
n
d
o
o
r
M
o
t
o
r
O
u
t
p
u
t
hp 0.75 1.5 0.75 1.5 2 3 0.75 1.5 2 3 0.75 1.5 2 3
Indoor
B
l
o
w
e
r
M
o
t
o
r
OutputkW0.56 1.1 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2
B
l
o
w
e
r
M
o
t
o
r
Full load amps4.6 11.5 4.6 5.7 7.5 10.6 2.3 2.8 3.4 4.8 2.3 2.4 2.7 3.9
M
o
t
o
r
Locked rotoramps10 55 10 40 46.9 66 5.4 20 20.4 26.8 5.4 15 16.2 23.4
O
p
t
i
o
n
a
l
P
o
w
e
r
Horsepower (W)1/2(363)
OptionalPower
E
x
h
a
u
s
t
F
a
n
Full load amps4.4 1.7
E
x
h
a
u
s
t
F
a
n
Locked rotoramps4.7 4.1
ServiceOutlet(2)115 voltGFCI(amprating)15
LCA/LGA048SMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 23.4 12.2 7.1 5.8
C
o
m
p
r
e
s
s
o
r
Locked rotorampseach 110.0 90.0 46.0 37.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 60 70 35 35 40 40 20 20 20 20 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 60 60 30 35 35 40 20 20 20 20 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 41 48 27 28 30 33 15 15 16 17 13 13 13 14
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 37 44 23 24 26 29 13 13 14 15 11 11 11 13
LCA/LGA048HMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 23.7 13.5 7.4 5.8
C
o
m
p
r
e
s
s
o
r
Locked rotorampseach 129.0 99.0 49.5 40.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 60 70 40 40 40 45 20 20 20 20 15 15 15 15
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 60 60 35 35 40 40 20 20 20 20 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 42 48 29 30 32 35 15 16 16 18 13 13 13 14
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 37 44 24 25 27 30 13 14 14 16 11 11 11 13
ModelNo.LCA/LGA060
Line voltage data—60 Hz208/230v-
1 phase208/230v 3 phase460v 3 phase575v 3 phase
O
u
t
d
o
o
r
F
a
n
M
o
t
o
r
Full load amps2.4 1.3 1.0
O
u
t
d
o
o
r
Fan MotorLocked rotoramps4.7 2.4 1.9
I
n
d
o
o
r
M
o
t
o
r
O
u
t
p
u
t
hp 0.75 1.5 0.75 1.5 2 3 0.75 1.5 2 3 0.75 1.5 2 3
Indoor
B
l
o
w
e
r
M
o
t
o
r
OutputkW0.56 1.1 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2 0.56 1.1 1.5 2.2
B
l
o
w
e
r
M
o
t
o
r
Full load amps4.6 11.5 4.6 5.7 7.5 10.6 2.3 2.8 3.4 4.8 2.3 2.4 2.7 3.9
M
o
t
o
r
Locked rotoramps10 55 10 40 46.9 66 5.4 20 20.4 26.8 5.4 15 16.2 23.4
O
p
t
i
o
n
a
l
P
o
w
e
r
Horsepower (W)1/2(363)
OptionalPower
E
x
h
a
u
s
t
F
a
n
Full load amps4.4 1.7
E
x
h
a
u
s
t
F
a
n
Locked rotoramps4.7 4.1
ServiceOutlet(2)115 voltGFCI(amprating)15
LCA/LGA060SMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 26.9 16.7 8.6 6.0
C
o
m
p
r
e
s
s
o
r
Locked rotorampseach 141.0 110.0 55.0 44.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 70 70 45 50 50 50 20 25 25 25 15 15 15 20
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 60 70 40 45 45 50 20 20 20 25 15 15 15 15
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 46 52 33 34 36 39 17 17 18 19 13 13 13 15
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 41 48 28 29 31 34 15 15 16 17 11 11 12 13
LCA/LGA060HMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 28.8 17.3 9.0 7.1
C
o
m
p
r
e
s
s
o
r
Locked rotorampseach 169.0 123.0 62.0 50.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 70 70 50 50 50 50 25 25 25 25 20 20 20 20
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 70 70 45 45 45 50 20 20 20 25 15 15 15 20
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 48 55 34 35 36 40 17 18 18 20 14 14 15 16
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 44 50 29 30 32 35 15 16 16 18 13 13 13 14
*RefertoNationalorCanadian Electrical Code manualto determine wire, fuse and disconnectsizerequirements.
NOTE—Extremesofoperating range are plusand minus10 %ofline voltage.
NOTE—Wherecurrentdoesnotexceed 100 amps,HACR type circuitbreaker maybe used in place of fuse(U.S.only).

Page 7
ELECTRICALDATA6TON
ModelNo.LCA/LGA072
Line voltage data—60 Hz208/230v
3 phase460v 3 phase575v 3 phase
O
u
t
d
o
o
r
F
a
n
M
o
t
o
r
Full load amps2.4 1.3 1.0
O
u
t
d
o
o
r
Fan MotorLocked rotoramps4.7 2.4 1.9
M
o
t
o
r
O
u
t
p
u
t
hp 1.5 2 3 1.5 2 3 1.5 2 3
Indoor
B
l
o
w
e
r
M
o
t
o
r
OutputkW1.1 1.5 2.2 1.1 1.5 2.2 1.1 1.5 2.2
I
n
d
o
o
r
B
l
o
w
e
r
M
o
t
o
r
Full load amps5.7 7.5 10.6 2.8 3.4 4.8 2.4 2.7 3.9
M
o
t
o
r
Locked rotoramps40 46.9 66 20 20.4 26.8 15 16.2 23.4
O
p
t
i
o
n
a
l
P
o
w
e
r
Horsepower (W)1/2(363)
OptionalPower
E
x
h
a
u
s
t
F
a
n
Full load amps4.4 1.7
E
x
h
a
u
s
t
F
a
n
Locked rotoramps4.7 4.1
ServiceOutlet(2)115 voltGFCI(amprating)15
LCA/LGA072SMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 20.7 9.0 7.4
CompressorLocked rotorampseach 156.0 70.0 54.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 50 60 60 25 25 25 20 20 20
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 50 50 50 20 20 25 20 20 20
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 39 41 44 18 18 20 15 15 16
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 34 36 39 16 16 18 13 13 15
LCA/LGA072HMODELS
C
o
m
p
r
e
s
s
o
r
Rated load ampseach 19.9 9.0 7.4
CompressorLocked rotorampseach 156.00 70.0 54.0
R
e
c
.
m
a
x
.
f
u
s
e
s
i
z
e
(
a
m
p
s
)
WithExhaustFan 50 50 60 25 25 25 20 20 20
R
e
c
.
m
a
x
.
f
u
s
e
size(amps)Less ExhaustFan 50 50 50 20 20 25 20 20 20
*
M
i
n
i
m
u
m
C
i
r
c
u
i
t
A
m
p
a
c
i
t
y
WithExhaustFan 38 40 43 18 18 20 15 15 16
*
M
i
n
i
m
u
m
CircuitAmpacityLess ExhaustFan 33 35 38 16 16 18 13 13 15
*RefertoNationalorCanadian Electrical Code manualto determine wire, fuse and disconnectsizerequirements.
NOTE—Extremesofoperating range are plusand minus10 %ofline voltage.
NOTE—Wherecurrentdoesnotexceed 100 amps,HACR type circuitbreaker maybe used in place of fuse(U.S.only).

Page 8
OPTIONALELECTRIC HEATACCESSORIES-LCA UNITS
UNIT FUSE BLOCKSWITHELECTRIC HEAT
UnitModelNo.LCA036
SLCA036 HLCA042 SLCA042 HLCA048 SLCA048 HLCA060 SLCA060 HLCA072 SLCA072H
E
l
e
c
t
r
i
c
ModelNo.EHA(see ElectricHeatDatatablesforadditional information)
Electric
HeatkWInputRange 7,10 15 &20 7,10,15,20 &25 10,15,20,
25,&30
208/230v-1ph 26L27 26L26 26L29 26L29 26L32 26L32 26L33 26L34 ---- ----
.
7
5
h
p
208/230v-3ph 26L35 26L35 26L35 26L36 26L36 26L36 26L37 26L39 ---- ----
.
7
5
h
p
(.56 kW)460v-3ph 26L43 26L43 26L43 26L43 26L44 26L44 26L44 26L44 ---- ----
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L43 ---- ----
208/230v-1ph 26L30 26L28 26L31 26L31 26L33 26L33 26L34 26L34 ---- ----
W
i
t
h
o
u
t
1
.
5
h
p
208/230v-3ph 26L35 26L35 26L35 26L36 26L36 26L36 26L39 26L39 26L41 26L41
Without
P
o
w
e
r
1
.
5
h
p
(1.1kW)460v-3ph 26L43 26L43 26L43 26L43 26L44 26L44 26L44 26L44 26L44 26L44
P
o
w
e
r
Exhaust
F
a
n
s
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44
F
a
n
s
2
h
p
208/230v-3ph 26L35 26L35 26L36 26L36 26L36 26L37 26L40 26L40 26L41 26L41
2 hp
(
1
.
5
k
W
)
460v-3ph 26L43 26L43 26L43 26L43 26L44 26L44 26L44 26L44 26L44 26L44
(
1
.
5
k
W
)
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44
3
h
p
208/230v-3ph 26L36 26L36 26L36 26L37 26L37 26L37 26L41 26L41 26L41 26L41
3 hp
(
2
.
2
k
W
)
460v-3ph 26L43 26L44 26L43 26L43 26L44 26L44 26L45 26L45 26L45 26L45
Unit
F
u
s
e
(
2
.
2
k
W
)
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44 26L44
F
u
s
e
Block 208/230v-1ph 26L30 26L26 26L31 26L31 26L33 26L33 26L34 26L34 ---- ----
B
l
o
c
k
.
7
5
h
p
208/230v-3ph 26L35 26L36 26L36 26L36 26L36 26L37 26L40 26L41 ---- ----
.
7
5
h
p
(.56 kW)460v-3ph 26L43 26L43 26L43 26L43 26L44 26L44 26L44 26L45 ---- ----
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 ---- ----
208/230v-1ph 26L31 26L30 26L31 26L31 26L34 26L34 26L34 26L34 ---- ----
W
i
t
h
1
.
5
h
p
208/230v-3ph 26L36 26L36 26L36 26L37 26L37 26L37 26L41 26L41 26L41 26L41
With
P
o
w
e
r
1
.
5
h
p
(1.1kW)460v-3ph 26L43 26L43 26L43 26L43 26L44 26L44 26L45 26L45 26L45 26L45
P
o
w
e
r
Exhaust
F
a
n
s
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44 26L44
F
a
n
s
2
h
p
208/230v-3ph 26L36 26L36 26L37 26L37 26L37 26L38 26L41 26L41 26L41 26L41
2 hp
(
1
.
5
k
W
)
460v-3ph 26L43 26L44 26L43 26L44 26L44 26L44 26L45 26L45 26L45 26L45
(
1
.
5
k
W
)
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44 26L44
3
h
p
208/230v-3ph 26L36 26L38 26L37 26L40 26L38 26L40 26L41 26L41 26L42 26L42
3 hp
(
2
.
2
k
W
)
460v-3ph 26L43 26L44 26L44 26L44 26L44 26L44 26L45 26L45 26L45 26L45
(
2
.
2
k
W
)
575v-3ph 26L43 26L43 26L43 26L43 26L43 26L43 26L44 26L44 26L44 26L44
LTB2ELECTRIC HEAT TERMINALBLOCK —LTB2-175 (1ph) (32L76)175 amps,LTB2-175-(3ph) (32L77)175 amps
(Required ForUnitsWithoutDisconnect/CircuitBreakerButWithSinglePointPowerSource)
7,10,15,
2
0
a
n
d
2
5
k
W
.75 hp (.56
kW)32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76
LTB2
T
e
r
m
i
n
a
l
2
0
a
n
d
2
5
k
W
1ph 1.5hp(1.1
kW)32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76 32L76
L
T
B
2
Terminal
Block 7,10,15,20,25
a
n
d
3
0
k
W
1.5hp(1.1
kW)32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77
7
,
1
0
,
1
5
,
2
0
,
2
5
and 30 kW
3
p
h
2hp(1.5kW)32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77
3
p
h
3hp(2.2kW)32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77 32L77
NOTE—TerminalBlock isfactoryinstalledin unitswithfactoryinstalledelectricheatwithoutdisconnect/circuitbreakerbutwithsinglepoint
powersource.

Page 9
BELTDRIVE BLOWER DATA
BLOWERTABLEINCLUDES RESISTANCEFORLCA BASE UNITONLYWITH DRYINDOOR COILAND AIRFILTERSINPLACE.
ADD:1-Wetindoorcoil air resistance ofselected unit.
2-Anyfactoryinstalled optionsair resistance(electricheatsection,economizer,etc.)
3-Anyfieldinstalled accessoriesair resistance(ductresistance,diffuser,etc.)
Then determine fromblowertable blower motoroutputand driverequired.
See Page 26 forblower motorsand drivesand Page 27 forwetcoil and options/accessoryair resistance data.
MINIMUMAIRVOLUMEREQUIREDFOR USE WITHOPTIONALELECTRIC HEAT
7,10,15,20 kWElectricHeat-1400 cfm (660 L/s)208/230 volt, 1500 cfm (710 L/s)460 &575 volt
25 kWElectricHeat-2000 cfm (945 L/s)
30 kWElectricHeat-2400 cfm (1135 L/s)
NOTE-LCA UNITSARENOTU.L.APPROVEDFOROPERATION ABOVE 1325 RPM.BOLDITALICSINDICATEFIELDFURNISHED DRIVE.
LCA BASE UNIT
A
i
r
V
o
l
u
m
e
TotalStaticPressure—Inches WaterGauge(Pa)
A
i
r
Volume
c
f
m
.00 (00).20 (50).40 (100).60 (150).80 (200)1.00 (250)1.20 (300)1.40 (350)1.60 (400)1.80 (450)
V
o
l
u
m
e
cfm
(L/s)RPMBHP
(kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)
900
(427)310 0.05 (0.04)455 0.10 ((0.07)595 0.15 (0.11)720 0.25 (0.19)825 0.40 (0.30)925 0.55 (0.41)1015 0.70 (0.52)1100 0.90 (0.67)1180 1.10 (0.82)1255 1.30 (0.97)
1000
(474)330 0.05 (0.04)470 0.10 (0.07)605 0.20 (0.15)725 0.30 (0.22)830 0.40 (0.30)925 0.55 (0.41)1015 0.70 (0.52)1095 0.90 (0.67)1175 1.10 (0.82)1250 1.30 (0.97)
1200
(568)375 0.10 (0.07)505 0.15 (0.11)630 0.25 (0.19)740 0.35 (0.26)840 0.45 (0.34)930 0.60 (0.45)1015 0.75 (0.56)1095 0.90 (0.67)1170 1.10 (0.82)1240 1.30 (0.97)
1400
(663)425 0.15 (0.11)545 0.20 (0.15)660 0.30 (0.22)760 0.40 (0.30)855 0.50 (0.37)940 0.65 (0.48)1020 0.80 (0.60)1100 0.95 (0.71)1170 1.10 (0.82)1240 1.35 (1.01)
1600
(757)475 0.20 (0.15)590 0.30 (0.22)695 0.40 (0.30)790 0.50 (0.37)875 0.60 (0.45)960 0.75 (0.56)1035 0.90 (0.67)1110 1.05 (0.78)1180 1.25 (0.93)1245 1.40 (1.04)
1800
(850)535 0.30 (0.22)640 0.40 (0.30)735 0.50 (0.37)820 0.60 (0.45)905 0.70 (0.52)980 0.85 (0.63)1055 1.00 (0.75)1125 1.15 (0.86)1195 1.35 (1.01)1255 1.50 (1.12)
2000
(945)595 0.40 (0.30)690 0.50 (0.37)775 0.60 (0.45)860 0.70 (0.52)935 0.85 (0.63)1010 1.00 (0.75)1080 1.15 (0.86)1145 1.30 (0.97)1210 1.50 (1.12)1270 1.65 (1.23)
2200
(1040)655 0.55 (0.41)740 0.65 (0.48)820 0.75 (0.56)895 0.85 (0.63)970 1.00 (0.75)1040 1.15 (0.86)1105 1.30 (0.97)1170 1.45 (1.08)1230 1.65 (1.23)1290 1.85 (1.38)
2400
(1135)710 0.70 (0.52)790 0.80 (0.60)870 0.95 (0.71)940 1.05 (0.78)1010 1.20 (0.90)1075 1.35 (1.01)1135 1.50 (1.12)1200 1.70 (1.27)1260 1.85 (1.38)1315 2.05 (1.53)
2600
(1229)770 0.90 (0.67)845 1.00 (0.75)915 1.15 (0.86)985 1.30 (0.97)1050 1.40 (1.04)1110 1.55 (1.16)1170 1.75 (1.31)1230 1.90 (1.42)1285 2.10 (1.57)----
2800
(1323)830 1.10 (0.82)900 1.25 (0.93)965 1.35 (1.01)1030 1.50 (1.12)1090 1.65 (1.23)1150 1.85 (1.38)1210 2.00 (1.49)1265 2.20 (1.64)1320 2.35 (1.75)----
3000
(1418)890 1.35 (1.01)955 1.50 (1.12)1015 1.65 (1.23)1075 1.80 (1.34)1135 1.95 (1.45)1190 2.10 (1.57)1245 2.30 (1.72)1300 2.50 (1.87)---- ----
BLOWERTABLEINCLUDES RESISTANCEFORLGA BASE UNITONLYWITH DRYINDOOR COILAND AIRFILTERSINPLACE.
ADD:1-Wetindoorcoil air resistance ofselected unit.
2-Anyfactoryinstalled optionsair resistance(economizer,etc.)
3-Anyfieldinstalled accessoriesair resistance(ductresistance,diffuser,etc.)
Then determine fromblowertable blower motoroutputand driverequired.
See Page 26 forblower motorsand drivesand Page 27 forwetcoil and options/accessoryair resistance data.
NOTE-LGA UNITSARENOTU.L.APPROVEDFOROPERATION ABOVE 1325 RPM.BOLDITALICSINDICATEFIELDFURNISHED DRIVE.
LGA BASE UNIT
A
i
r
V
o
l
u
m
e
TotalStaticPressure—Inches WaterGauge(Pa)
A
i
r
Volume
c
f
m
.00 (00).20 (50).40 (100).60 (150).80 (200)1.00 (250)1.20 (300)1.40 (350)1.60 (400)1.80 (450)
V
o
l
u
m
e
cfm
(L/s)RPMBHP
(kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)RPMBHP (kW)
900
(425)350 0.05 (0.04)495 0.10 (0.07)630 0.20 (0.15)750 0.30 (0.22)855 0.40 (0.30)950 0.60 (0.45)1035 0.75 (0.56)1120 1.00 (0.75)1195 1.25 (0.93)1270 1.50 (1.12)
1000
(470)375 0.10 (0.07)515 0.15 (0.11)645 0.20 (0.15)760 0.30 (0.22)860 0.45 (0.34)955 0.60 (0.45)1040 0.75 (0.56)1120 1.00 (0.75)1195 1.20 (0.90)1270 1.45 (1.08)
1200
(565)430 0.15 (0.11)560 0.20 (0.15)680 0.25 (0.19)785 0.35 (0.26)885 0.50 (0.37)970 0.65 (0.48)1055 0.80 (0.60)1130 1.00 (0.75)1205 1.20 (0.90)1275 1.45 (1.08)
1400
(660)490 0.20 (0.15)615 0.30 (0.22)725 0.35 (0.26)820 0.45 (0.34)910 0.55 (0.41)995 0.70 (0.52)1075 0.85 (0.63)1150 1.05 (0.78)1220 1.25 (0.93)1285 1.45 (1.08)
1600
(755)560 0.35 (0.26)670 0.40 (0.30)770 0.50 (0.37)860 0.60 (0.45)945 0.70 (0.52)1025 0.80 (0.60)1100 0.95 (0.71)1170 1.15 (0.86)1240 1.30 (0.97)1305 1.50 (1.12)
1800
(850)630 0.50 (0.37)730 0.55 (0.41)820 0.65 (0.48)905 0.75 (0.56)985 0.85 (0.63)1060 1.00 (0.75)1130 1.10 (0.82)1200 1.30 (0.97)1265 1.45 (1.08)1325 1.65
(1.23)
2000
(945)700 0.65 (0.48)790 0.75 (0.56)875 0.85 (0.63)955 0.95 (0.71)1030 1.05 (0.78)1100 1.20 (0.90)1165 1.30 (0.97)1230 1.45 (1.08)1295 1.65 (1.23)----
2200
(1040)770 0.85 (0.63)855 0.95 (0.71)930 1.05 (0.78)1005 1.15 (0.86)1075 1.30 (0.97)1140 1.40 (1.04)1205 1.55 (1.16)1265 1.70 (1.27)1325 1.85
(1.38)----
2400
(1135)840 1.15 (0.86)920 1.25 (0.93)990 1.35 (1.01)1060 1.45 (1.08)1125 1.55 (1.16)1190 1.70 (1.27)1250 1.85 (1.38)1305 2.00 (1.49)---- ----
2600
(1225)910 1.45 (1.08)980 1.55 (1.16)1050 1.65 (1.23)1115 1.75 (1.31)1175 1.90 (1.42)1235 2.05 (1.53)1295 2.20 (1.64)---- ---- ----
2800
(1320)980 1.80 (1.34)1050 1.90 (1.42)1110 2.05 (1.53)1170 2.15 (1.60)1230 2.30 (1.72)1285 2.40 (1.79)---- ---- ---- ----
3000
(1415)1050 2.20 (1.64)1115 2.35 (1.75)1175 2.45 (1.83)1230 2.60 (1.94)1285 2.70 (2.01)---- ---- ---- ---- ----

Page 10
BELTDRIVE BLOWER DATA
FACTORYINSTALLED BELT DRIVE KITSPECIFICATIONS
MotorOutputsRPMRange
Nominalhp Maximumhp NominalkWMaximumkWDrive 1 Drive 2 Drive 3 Drive 4
Standard orHigh Efficiency -1.5 1.72 1.1 1.3 615 -920 800 -1105 ---- ----
Standard orHigh Efficiency -2 2.3 1.5 1.7---- ---- 920 -1230 ----
StandardEfficiency Only-3 3.45 2.2 2.6---- ---- ---- 1070 -1325
*Using totalairvolume and systemstaticpressurerequirementsdetermine fromblowerperformancetablesrpmand motoroutputrequired.Maximumusable outputofmotors
furnished byLennoxareshown. InCanada,nominalmotoroutputisalsomaximumusablemotoroutput. If motorsofcomparable outputare used,be suretokeep withinthe
servicefactorlimitationsoutlined on the motornameplate.DIRECTDRIVE BLOWER DATA
LGA/LCA036-060 DIRECTDRIVE BLOWERPERFORMANCE@208 VOLTS(Downflow)
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
AirVolume atVariousBlowerSpeeds
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
High Medium-High MediumMedium-LowLow
in.w.g.Pa cfmL/s cfmL/s cfmL/s cfmL/s cfmL/s
0 0 2530 1195 2265 1070 1970 930 1720 810 1440 680
.10 25 2495 1175 2235 1055 1945 920 1700 800 1430 675
.20 50 2450 1155 2200 1040 1915 905 1670 790 1415 670
.30 75 2405 1135 2160 1020 1880 890 1640 775 1390 655
.40 100 2355 1110 2115 1000 1840 870 1605 755 1360 640
.50 125 2300 1085 2065 975 1795 845 1565 740 1330 630
.60 150 2235 1055 2010 950 1745 825 1515 715 1290 610
.70 175 2165 1020 1945 920 1690 800 1460 690 1245 590
.80 200 2090 985 1875 885 1620 765 1400 660 1195 565
.90 225 2000 945 1790 845 1550 730 1330 630 1130 535
1.00 250 1895 895 1695 800 1460 690 1250 590 1055 500
1.10 275 1770 835 1580 745 1360 640 1160 545 975 460
1.20 300 1620 765 1440 680 1240 585 1055 500 870 410
NOTE—All airdataismeasured externalto unitwith2rowdry coil and 2 inch(51 mm) filters.
LGA/LCA036-060 DIRECTDRIVE BLOWERPERFORMANCE@230 VOLTS(Downflow)
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
AirVolume atVariousBlowerSpeeds
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
High Medium-High MediumMedium-LowLow
in.w.g.Pa cfmL/s cfmL/s cfmL/s cfmL/s cfmL/s
0 0 2750 1300 2500 1180 2245 1060 1955 925 1630 770
.10 25 2705 1275 2470 1165 2215 1045 1925 910 1600 755
.20 50 2650 1250 2430 1145 2180 1030 1890 890 1570 740
.30 75 2585 1220 2390 1130 2140 1010 1850 875 1535 725
.40 100 2535 1195 2340 1105 2100 990 1810 855 1500 710
.50 125 2475 1170 2290 1080 2050 965 1760 830 1455 685
.60 150 2405 1135 2225 1050 1995 940 1705 805 1405 665
.70 175 2330 1100 2155 1015 1930 910 1640 775 1365 645
.80 200 2245 1060 2075 980 1865 880 1575 745 1310 620
.90 225 2155 1015 1975 930 1780 840 1495 705 1240 585
1.00 250 2050 965 1860 880 1690 800 1405 665 1150 545
1.10 275 1935 915 1720 810 1585 750 1290 610 1040 490
1.20 300 1805 850 1560 735 1450 685 1160 545 915 430
NOTE—All airdataismeasured externalto unitwith2rowdry coil and 2 inch(51 mm) filters.
LGA/LCA036-060 DIRECTDRIVE BLOWERPERFORMANCE@460/575 VOLTS(Downflow)
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
AirVolume atVariousBlowerSpeeds
E
x
t
e
r
n
a
l
S
t
a
t
i
c
P
r
e
s
s
u
r
e
High MediumLow
in.w.g.Pa cfmL/s cfmL/s cfmL/s
0 0 2820 1330 2460 1160 1975 930
.10 25 2770 1305 2430 1145 1950 920
.20 50 2720 1285 2395 1130 1920 905
.30 75 2670 1260 2345 1105 1885 890
.40 100 2610 1230 2310 1090 1845 870
.50 125 2545 1200 2260 1065 1800 850
.60 150 2475 1170 2200 1040 1755 830
.70 175 2400 1130 2140 1010 1700 800
.80 200 2315 1090 2065 975 1635 770
.90 225 2220 1045 1980 935 1565 740
1.00 250 2115 1000 1880 885 1480 700
1.10 275 2000 945 1760 830 1370 647
1.20 300 1860 875 1615 760 1260 595
NOTE—All airdataismeasured externalto unitwith2rowdry coil and 2 inch(51 mm) filters.

Page 11
BLOWER DATA
AIR RESISTANCE-FACTORYINSTALLEDOPTIONS/FIELDINSTALLED ACCESSORIES
A
i
r
V
o
l
u
m
e
TotalResistance —inches watergauge(Pa)
A
i
r
V
o
l
u
m
e
WetIndoorCoil
E
l
e
c
t
r
i
c
H
e
a
t
cfmL/sLCA/LGA
036S/036H/042S/
042H/048S/060S(2row)
LCA/LGA
048H/060H/072S(3row)LCA/LGA072H (4row)
ElectricHeat
(LCA Models)Economizer
800 380 0.02 (4)0.04 (9)0.05 (13)0.04 (10)0.04 (10)
1000 470 0.02 (4)0.05 (12)0.07 (18)0.06 (15)0.04 (10)
1200 565 0.03 (8)0.06 (16)0.09 (24)0.09 (22)0.04 (10)
1400 660 0.04 (10)0.08 (21)0.12 (31)0.12 (30)0.04 (10)
1600 755 0.05 (13)0.10 (26)0.15 (38)0.16 (40)0.04 (10)
1800 850 0.06 (16)0.12 (31)0.18 (46)0.21 (52)0.05 (12)
2000 945 0.07 (18)0.14 (36)0.21 (53)0.25 (62)0.05 (12)
2200 1040 0.09 (21)0.17 (42)0.25 (62)0.31 (77)0.05 (12)
2400 1135 0.11 (27)0.19 (48)0.28 (70)0.37 (92)0.05 (12)
2600 1225 0.13 (32)0.22 (54)0.31 (77)0.43 (107)0.06 (15)
2800 1320 0.16 (40)0.25 (63)0.36 (88)0.50 (125)0.06 (15)
3000 1415 0.20 (50)0.29 (71)0.41 (101)0.58 (144)0.06 (15)
AIR RESISTANCE-CEILINGDIFFUSERS
A
i
r
V
o
l
u
m
e
TotalResistance —inches watergauge(Pa)
A
i
r
V
o
l
u
m
e
RTD9Step-DownDiffuser
F
D
9
F
l
u
s
h
RTD11 Step-DownDiffuser
F
D
1
1
cfmL/s2Ends
Open1Side 2EndsOpenAll Ends& Sides Open
F
D
9
F
l
u
s
h
Diffuser2Ends
Open1Side 2EndsOpenAll Ends& Sides Open
F
D
1
1
Flush
Diffuser
800 380 0.15 (37 0.13 (32)0.11 (27)0.11 (27) ---- ---- ---- ----
1000 470 0.19 (47 0.16 (40)0.14 (35)0.14 (35) ---- ---- ---- ----
1200 565 0.25 (62 0.20 (50)0.17 (42)0.17 (42) ---- ---- ---- ----
1400 660 0.33 (82 0.26 (65)0.20 (50)0.20 (50) ---- ---- ---- ----
1600 755 0.43 (107 0.32 (80)0.20 (50)0.24 (60) ---- ---- ---- ----
1800 850 0.56 (139 0.40 (100)0.30 (75)0.30 (75)0.13 (32)0.11 (27)0.09 (22)0.09 (22)
2000 945 0.73 (182 0.50 (125)0.36 (90)0.36 (90)0.15 (37)0.13 (32)0.11 (27)0.10 (25)
2200 1040 0.95 (237 0.63 (157)0.44 (110)0.44 (110)0.18 (45)0.15 (37)0.12 (30)0.12 (30)
2400 1135 ---- ---- ---- ---- 0.21 (52)0.18 (45)0.15 (37)0.14 (35)
2600 1225 ---- ---- ---- ---- 0.24 (60)0.21 (52)0.18 (45)0.17 (42)
2800 1320 ---- ---- ---- ---- 0.27 (67)0.24 (60)0.21 (52)0.20 (50)
3000 1415 ---- ---- ---- ---- 0.32 (80)0.29 (72)0.25 (62)0.25 (62)
AIRTHROWDATA-RTD9-65 CEILINGDIFFUSER
AirVolume¡Effective Throw
cfmL/sft.m
1000 470 10-17 3-5
1200 565 11-18 3-5
1400 660 12-19 4-6
1600 755 12-20 4-6
1800 850 13-21 4-6
2000 945 14-23 4-7
2200 1040 16-25 5-8
AIRTHROWDATA-RTD11-95 CEILINGDIFFUSER
2600 1225 24-29 7-9
2800 1320 25-30 8-9
3000 1415 27-33 8-10
3200 1510 28-35 9-11
3400 1605 30-37 9-11
¡Effectivethrowbased on terminalvelocitiesof75 ft. (22.9m) per minute.
AIRTHROWDATA-FD9-65 CEILINGDIFFUSER
AirVolume¡Effective Throw—ft.(m)
cfmL/sft.m
1000 470 15-20 5-6
1200 565 16-22 5-7
1400 660 17-24 5-7
1600 755 18-25 5-7
1800 850 20-28 6-9
2000 945 21-29 6-9
2200 1040 22-30 7-9
AIRTHROWDATA-FD11-95 CEILINGDIFFUSER
2600 1225 19-24 6-7
2800 1320 20-28 6-9
3000 1415 21-29 6-9
3200 1510 22-29 7-9
3400 1605 22-30 7-9
¡Effectivethrowbased on terminalvelocitiesof75 ft. (22.9m) per minute.

Page 12
LGAPARTSARRANGEMENT
FIGURE1
HEATEXCHANGER
EVAPORATOR COIL
FILTER
ECONOMIZER
(OPTIONAL)
DISCONNECT
(OPTIONAL)
120VGFIOUTLET
(OPTIONAL)BLOWERBURNERS
GAS VALVE
COMBUSTION AIR
BLOWER
COMPRESSOR
CONDENSERFAN
CONTROLPANEL
LCA PARTSARRANGEMENT
FIGURE2
EVAPORATOR COIL
FILTERS
ECONOMIZER
(OPTIONAL)
DISCONNECT
(OPTIONAL)120VGFIOUTLET
(OPTIONAL)
BLOWER
ELECTRICALHEAT
(OPTIONAL)
COMPRESSOR
CONTROLPANEL
CONDENSERFAN
FUSE BOX
(ELECTRIC HEATONLY)

Page 13
F
I
G
U
R
E
3
LCA/LGA036-042-048-060-072
DIRECTDRIVE MOTOR
LCA/LGA036-042-048-060-072
BELT DRIVE MOTOR
MAIN CONTROL(A55)ECONOMIZERMODULE(A56)
FAN RELAY
(K10)
BLOWER CONTACTOR(K3)
HEATRELAY(K36)COMPRESSOR
(K1)
TRANSFORMER(T1)
MAIN CONTROL(A55)
ECONOMIZERMODULE(A56)
TERMINALSTRIP(TB34)
3PHASE HIGHEFFICIENCYONLY
TERMINALSTRIP(TB34)
TRANSFORMER(T1)
FAN
RELAY
(K10)
BLOWER
CONTACTOR(K3)
COMPRESSOR
(K1)
OVERLOAD RELAY(S42)
3PHASE HIGHEFFICIENCYONLY
POWEREXHAUSTRELAY(K65)
POWEREXHAUST
RELAY(K65)

Page 14
I-UNITCOMPONENTS
LGA/LCAunitsareconfigureto orderunits(CTO).The
LGAandLCAunitcomponentsareshowninfigures1and2.
L1,L2,and L3 wiring is colorcoded;L1 isred,L2 is yellow,
and L3 isblue.
A-ControlBoxComponents
LGA/LCAcontrolbox componentsareshowninfigure 3.
The controlboxislocated inthe upperportion of the com-
pressorcompartment.
1-DisconnectSwitchS48 (Optionalall units)
LGA/LCAunitsmaybe equipped with an optionaldisconnect
switchS48.Otherfactoryorfieldinstalled optionalcircuit
breakersmaybe used,such asCB10.S48 and CB10 are
toggleswitches,whichcan be used bythe servicetechni-
cian to disconnectpowertothe unit.
2-ControlTransformerT1(all units)
All LGA/LCAseriesunitsuse a singleline voltage to
24VACtransformermounted inthe controlbox.Trans-
formersuppliespowertocontrolcircuitsintheunit.The
transformerisrated at70VA and isprotected bya 3.5
ampcircuitbreaker (CB8).The 208/230 (Y)voltage
transformersusetwo
primary voltage taps
as showninfigure 4,
while 460 (G)and 575
(J)voltage transform-
ersuseasingle prima-
ry voltage tap.
3-C.A.B.TransformersT3
(LGA460V&575Vunits)
All LGA460 (G)and 575 (J)voltage unitsuse one autovolt-
age to 230VACtransformermounted inthe compressor
compartment. The transformerhasan outputrating of0.5A.
T3transformersupplies230 VACpowertocombustion air
blowermotor (B6).
4-TerminalStripsTB1 and TB34 (all units)
TB1terminalstripdistributes24Vpowerandcommonfrom
thethermostattothecontrolboxcomponents.TB34termi-
nalstrip distributes24VpowerfromT1tothe controlbox
components.
5-UnitFuse Block &Fuses F4(LCA units)
Line voltage fusesF4 provide shortcircuitand ground fault
protectiontoallcoolingcomponentsintheLCAunitswithelec-
tricheat. Single phase unitsusetwofusesand three phase
unitsusethree fuses.The fusesarerated in accordancewith
the amperage of the cooling components.
6-OutdoorFanCapacitorC1
(three phase units)
FancapacitorC1isused toassistinthestartupofcondens-
erfan B4.See table1for ratings
TABLE1
UnitVoltage CapacitorRating
208/230 10MF370V
460V10MF370V
575V10MF370V
7-CompressorContactorK1(all units)
K1isa24Vtolinevoltage contactorusedtoenergizethecom-
pressorandcondenserfaninresponsetothermostatdemand.
Three-phase unitsusethree-pole-double-break contactors.
Single-phase unitsusetwo-pole double break contactors.
NOTE-ContactorK1isenergized bythe IMC Controlsys-
tem.Refertothe operation sequenceforthe controlsys-
teminstalled.Theremaybea5minute delaydepending
on the systeminstalled.
8-BlowerContactorK3(all units)
BlowercontactorK3isusedinallunits.In directdriveunits,K3
isDPDTrelay. Insinglephasebeltdriveunits,K3isaDPcon-
tactorwhilethree-phase beltdriveunitsusea3PDBcontactor.
K3 hasa 24VACcoil usedtoenergizetheindoorblowermotor
B3,inresponseto blowerdemand.K3isenergized bymain
controlpanel(A55).
9-OutdoorFanRelay K10 (all units)
Outdoorfan relayK10,used in all units,isaDPDTrelaywith
a 24VACcoil. In all unitsK10 (energized byA55),energizes
condenserfan B4inresponsetothermostatdemand.Once
dischargepressureof275¦psigachieved,operationiscon-
trolled byLowambientswitch(S11).
10-Combustion AirBlowerRelay K13
(LGAunits)
Combustion airblower relayK13,used in all LGAunits,isa
DPDTrelaywitha 24VACcoil.K13isenergized bythemain
controlmoduleA55 aftera heating demand fromthe ther-
mostat. K13 remainsenergized throughout the heating de-
mand.When energized,K13 N.O.contacts closeto ener-
gizethe combustion airblowerand begin a heating
sequence.PressureswitchS18,located inthe gasheat
compartment, closesas combustion airstaticpressure
fallsto“prove”combustion airbloweroperation.When
S18 closes, the ignition controlsand gas valvesare ener-
gized to begin a heating sequence.
FIGURE4
BLUE YELLOW
ORANGE
RED
BLACK
230 VOLTS
208 VOLTS
PRIMARY
SECONDARY
208/230VTRANSFORMER

Page 15
11-PowerExhaustRelay K65 (PEF units)
PowerexhaustrelayK65 isaDPDTrelaywith a 24VAC
coil.K65 isused in all LGA/LCAunitsequippedwiththe
optionalpowerexhaust fans.K65 isenergized bythe
economizercontrolpanel(A56),afterthe economizer
dampersreach 50%open (adjustableinECTO).When
K65 closes, the exhaust fan B10 isenergized.
12-BlowerMotorOverloadRelay S42 (units
with high efficiency motors)
The blowermotoroverload relayisused in all Lseriesunits
equipped with high efficiency motors.The relay(S42)is con-
nected inline withthe blowermotortomonitorthe current flow
tothe motor.When the relay sensesan overload condition,a
setofnormally closed contactsopen to de-energize pin #9 in
plug 110ofthe A55maincontrolmodule.A55 de-energizesall
outputs.The overload relayhasan adjustablesetting and is
setperthe nameplatecurrentof the motor.All unitsare
equipped with a relaymanufactured bySiemenswhichisde-
tailed infigure 5.
13-StartCapacitorC7(single-phase)
Single-phase unitsuseastartcapacitor (C7)wired in
parallelwiththe compressorside of the dualcapacitor.
The startcapacitorislocated tothe side of the control-
panel.C7isengagedduringcompressorstart-upandis
switched off bythe potentialrelayasthe compressor
nearsfull speed.Capacitor ratingsmaybe different for
eachmotor,buttheratingandrepairpartnumberwillbe
printed on the side of the capacitor.
14-PotentialRelay K31 (single-phase)
Single-phase unitsuse a potentialrelaywhichcontrolsthe op-
eration of the starting circuit. The potentialrelayislocated to
the side of the unitcontrolpanel.The relayisnormally closed
when the compressor (contactorK1)isde-energized.Capaci-
tor(C7)isconnectedtoasetofN.C.K31 contactsandisused
to assist the compressorinstarting.When K1 energizes, the
compressorimmediatelybegins start-up.K31 remainsde-en-
ergized during compressorstart-up and the startcapacitor
(C7) remainsinthe circuit. Asthe compressorgains speed,
K31 isenergized byelectromotiveforcesgenerated bythe
compressor.When K31 energizes,its contactsopen totake
the startcapacitoroutof the circuit.
CAUTION
Electrostaticdischarge canaffectelectronic
components.Take precautionsduring furnace
installation and service to protect thefurnace’s
electronic controls.Precautionswill helptoavoid
controlexposuretoelectrostaticdischargeby
putting thefurnace,the controland thetechni-
cianat the same electrostaticpotential. Neutral-
ize electrostatic chargebytouching hand and all
toolson an unpainted unitsurface,suchas the
gas valve orblowerdeck,beforeperforming any
service procedure.
E
L
E
C
T
R
O
S
T
A
T
I
C
D
I
S
C
H
A
R
G
E
(
E
S
D
)
Precautions and Procedures
INTEGRATEDMODULAR CONTROLBOARDS
The Integrated ModularControl(IMC)isaseriesofcontrol
boardswhichintegratesmostcontrolfunctionsrequired forthe
LGA/LCAunits.The controlboardsarelocated intheupper
left hand cornerof the controlbox.The control includes
completeunitdiagnostics with permanentcode storage,
field programmablecontrolparametersand controlop-
tions,on-sitetesting,and serialcommunications.Two
differentprintedcircuitboards(seefigure6)make-upthe
modularconfigurationsfortheLGA/LCAunits.Seetable
2foralistofcontrolpanelsused foreach unit. Forfurther
informationrefertoIntegratedModularControlGuidesentwith
each unit. TABLE2
U
N
I
T
CONTROLPANELS
U
N
I
T
A55 A56
LGA X OPT
LCA X OPT
15-MainControlModuleA55 (all units)
The maincontrolmoduleA55 isthe heartof the system. It
controlsone compressor,one single ortwostage gas
valve,onebankofelectricheat, one outdoorfan,and one
blower.A55includesthethermostatinputs,serialcommu-
nicationsports,diagnostic code display,controlpushbutton,
systemconfigurationdipswitches,andfourexpansionports.A
diagnostic code listislocated on the back side of the access
panel.
16-EconomizerControlModuleA56
(Economizeronly)
TheeconomizercontrolmoduleA56 controlstheecono-
mizer.A56 hasfourdifferentcooling modes,sensible
temperature,outdoorenthalpy,differentialenthalpy,and
globalcontrol.

Page 16
SIEMENSOVERLOAD RELAY
Adjustrelayampsetting according tovalue given on the blowermotornameplate.Proper
relayampsetting equalsmotornameplateFLAXservicefactorof1.15 X.95.
Usesmall slotted screwdriverto adjustcontrolmode fromautomaticreset(A)tomanual
reset(H).
Controlmustbe inthe manualresetmode (H)to performatest. Press the red testbutton.
Green tripindicatorshould pop out. Press the blue resetscrewtoreset the relay.
BLUERESETBUTTONIN
FACTORY-SETAUTOMODE
(Turnclockwise toHfor
manualreset) GREENTRIPINDICATOR
(Flushwithsurface -- not tripped;
Above surface -- tripped)
AMPADJUSTMENTDIAL
REDTESTBUTTON
FIGURE5
P110 P111 P112 P113
P115
SENSORS
INPUTS
OUTPUTS
COMPRESSOR
SAFETYINPUTS
BURNER
INPUTS
ROOM
THERMOSTAT(A2)
A55
A56
TB1 connectstoP110.Roomthermostatconnectsto TB1.
P114
IMC BOARD INPUTSAND OUTPUTS
A55:
A56:
Optional
Economizer
and/orPower
ExhaustFan
1Blower
1Compressor
1Outdoorfan
1Gas valve
1Electricheatsection
IMC AND ADD-ON BOARD LOCATION AND OPERATION
FIGURE6
TB1

Page 17
LGA/LCA PLUMBINGCOMPONENTS
FIGURE7
LOWPRESSURE
SWITCH (S87)
SCROLL COMPRESSOR(B1)
LOWAMBIENT
SWITCH (S11)
LIQUIDLINE
SERVICE VALVE
CRANKCASE HEATER
(HR1)
HIGHPRESSURE
SWITCH (S4)
DISCHARGELINE
SERVICE VALVE
PRESSURETAP
RECIPROCATINGCOMPRESSOR
(B1)
LOWPRESSURE
SWITCH (S87)
LOWAMBIENT
SWITCH (S11)
LIQUIDLINE
SERVICE VALVE
HIGHPRESSURE
SWITCH (S4)
DISCHARGELINE
SERVICE VALVE
PRESSURETAP

Page 18
B-Cooling Components
LGA/LCAunitsuseindependentcooling circuits consisting
ofseparatecompressor,condensercoilandevaporatorcoil.
See figure 7.Unitsare equipped with a draw-through type
condenserfan.All unitsare equipped with eitherbelt-drive
ordirectdriveblowerswhichdrawairacross theevaporator
during unitoperation.
Cooling maybe supplemented byafactory-orfield-
installed economizer.The evaporatoris slab type and
usesathermostaticexpansion valve asthe primaryexpan-
sion device.Each evaporatorisalso equipped with enhanced
finsand rifled tubing. In all unitseachcompressorisprotected
byacrankcase heater,high pressureswitch and lowpres-
sureswitch.Additionalprotectionisprovidedbythelowam-
bientswitch and freezestat.
1-CompressorsB1(all units)
All LGA/LCA3through5ton (10.5to17.6kW)standardeffi-
ciency unitsuse one reciprocating typecompressor.AllLGA/
LCA6ton (21kW)standard efficiency unitsuse one scroll
compressor.All LGA/LCA3through 6 ton (10.5to 21 kW)
high efficiency unitsuse one scroll compressor.Compres-
sorsaresupplied by variousmanufacturers.Compressor
electricalspecifications varybymanufacturer.
WARNING
Electricalshock hazard.Compressormustbe
grounded.Do notoperatewithoutprotective cover
overterminals.Disconnectpowerbeforeremoving
protective cover.Discharge capacitorsbefore ser-
vicing unit.Failuretofollowthese precautions could
cause electricalshock resulting ininjuryordeath.
Eachcompressorisenergized byacorresponding com-
pressorcontactor.
NOTE-Refertothe wiring diagramsection forspecificunit
operation.
2-CompressorRun Capacitor(C12)
Single-phaseunitsusesingle-phasePSCcompressormo-
tors.PSCmotorsrequirearun capacitorC12.
Theruncapacitorisa“dual”capacitorwhichis shared withthe
condenserfanmotor.Adualcapacitorfunctionsastwocapac-
itorsinasinglecan.One side of the dualcapacitoris con-
nectedtothecompressorandtheothersideofthecapacitoris
connected tothe condenserfan.Eachside of the capacitor
hasa differentrating.
Capacitor ratingsmaybe different foreachmotor,but the rat-
ing and repairpartnumberisprinted on the capacitor.
3-Crankcase HeatersHR1(all units)
All LGA/LCAunitswithscroll compressorsuse belly-band
typecrankcaseheaters,whileallLGA/LCAunitswithrecip-
rocating compressorsuseinsertion type heaters.Heater
HR1isusedoncompressorB1.Crankcaseheaterwattage
variesby compressormanufacturer.
4-High PressureSwitchS4(all units)
The high pressureswitchisan auto-resetSPSTN.C.switch
which openson a pressurerise.All LGA/LCAunitsare
equipped withthis switch.The switchislocated inthe com-
pressordischargeline.S4iswiredinserieswiththecompres-
sorcontactorcoil.
When discharge pressurerisesto 450 +10 psig(3103+
69 kPa) (indicating a probleminthe system)the switch
opensand the compressorisde-energized (the econo-
mizercan continue to operate).When discharge pres-
suredropsto310+20psig(2147+138kPa)thepressure
switchwill close.
MaincontrolA55 hasathree-strikecounterbeforelock-
ingout.Thismeansthe controlwillallowthreehighpres-
suretripsperone thermostatdemand.The controlcan
be resetbybreaking and remaking the thermostatde-
mand ormanuallyresetting the control.
5-LowAmbientSwitches S11 (all units)
Thelowambientswitchisanauto-resetSPSTN.O.pres-
sureswitchwhich allowsformechanicalcooling opera-
tionatlowoutdoortemperatures.AllLGA/LCAunitsare
equipped withthis switch. In all modelsaswitchislo-
cated in eachliquidline priortothe indoorcoil section.
When liquid pressurerisesto 275 +10 psig(1896 +69
kPa), the switchclosesand the condenserfan isener-
gized.Whendischargepressureinbothrefrigerantcircuits
dropto 140 +10psig(965 +69 kPa), the switch opensand
thecondenserfanisde-energized.Thisintermittentfanop-
eration resultsin higherevaporating temperature allowing
the systemto operatewithouticing the evaporatorcoil and
losing capacity.
6-LowPressureSwitches S87 (all units)
The lowpressureswitchisan auto-resetSPSTN.O.
switch(heldN.C.byrefrigerantpressure)which opens
on a pressure drop.All LGA/LCAunitsare equipped
withthisswitch.Theswitchislocatedinthecompressor
suction line.
S87 iswired directlytothe maincontrolmoduleA55.

Page 19
The maincontrolmoduleA55 governsthe lowpressure
switchesby shunting the switchesduring startup until pres-
sureis stabilized.Afterthe shuntperiod, the controlhasa
three-strikecounter,duringfirstthermostatdemand,beforethe
compressorislocked out.Thecontrolisresetbybreakingand
remaking the thermostatdemand ormanuallyresetting the
control.
When suction pressure dropsto25+5 psig(172 ±34
kPa) (indicating lowpressure), the switchopensandthe
compressorisde-energized.The switch automatically
resetswhen pressureinthe suction line risesto55+5
psig(379 ±34 kPa).
7-Service Valves (optionalon LGA/LCA units)
LGA/LCAunitsmaybeequippedwithservicevalveslo-
cated inthe discharge and liquidlines.The service
valvesaremanuallyoperated valvesused forservice
operation.
8-FilterDrier(all units)
LGA/LCAunitshaveafilterdrierlocated inthe liquidline of
eachrefrigerantcircuitupstreamof the TXV inthe blower
compartment. The drier removes contaminantsand mois-
turefromthe system.
9-FreezestatsS49 (all units)
Each unitisequipped withalowtemperatureswitch(freezes-
tat)S49 locatedonareturn bend ofeach evaporatorcoil.
Eachfreezestatiswired tothe maincontrolmoduleA55.
EachfreezestatisaSPSTN.C.auto-resetswitchwhich
opensat29°F+3°F(-1.7°C+1.7°C)on a temperature drop
andclosesat58°F+4°F(14.4°C+2.2°C)on a tempera-
turerise.To preventcoil icing, freezestatsopen during
compressoroperation totemporarilydisablethe com-
pressoruntilthecoilwarmssufficientlytomeltanyaccu-
mulated frost.
Ifthefreezestatistrippingfrequentlyduetocoilicing,checkthe
unitcharge,airflowand filtersbefore allowing unitback in op-
eration.Makesureto eliminateconditionswhichmightpro-
mote evaporatorice buildup.
10-CondenserFanB4(all units)
RefertoSpecifications sectionof thismanualforspeci-
ficationsofcondenserfan B4 used in LGA/LCAunits.
The condenserfan used isasingle-phasemotor.The fan
maybe removed forservicing and cleaning byremoving
the fan grill.
C-BlowerCompartment
Overview
Unitsmaybe equipped with direct-drive orbelt-drive blow-
ers.Seeunitnameplateforblowertype.Directdriveblowers
will usea3/4hp.motor.Beltdriveblowerswillusea 1 1/2,2
or3 hp.motor.
Theblowerhousinginbelt-drivemodelscanberemovedfor
cleaningandinspection.Inaddition,removingblowerallows
access tothe heatexchangertubesforinspection.
Line and lowvoltage make-up in all modelsislocated inthe
uppercorneroftheblowercompartment.Electricalentrance
ismade through the base pan of the unitorthrough the cor-
nermullion forhorizontalposition units.Lowervoltage con-
nectionscanbeaccessedbyremoving the blowercompart-
ment frontpanel.Highvoltagecan beaccessed throughthe
makeup box coveron cornermullion.
Access (Figure 8)
In all models, the blowercan be accessed byremoving the
unitfrontpanelorendpanel.Inbelt-drivemodels,theblower
motorcan mosteasilybe accessed byremoving the blower
compartmentend panel.
Inallmodels,theevaporatorcoil,expansionvalveanddrain
pan can be accessed byremoving the blowercompartment
end panel.
1-TerminalStrip TB1
All unitsare equipped with a lowvoltage terminalstrip(TB1)
located abovethe line voltage make-up boxinside the blower
compartment. The stripisequipped withscrewterminals
which are used formaking all indoorthermostatand unitlow
voltage controlwiring connections.
2-LineVoltageTerminalStrip TB2
TB2isaterminalstripwhich providesameansforconnecting
all line voltage wiring.The stripislocated inthe line voltage
make-up boxinside the blowercompartment
3-BlowerWheel(all units)
All 3to6ton (10.5to21kW)LGA/LCAunitshave one 11 1/2
in.x9in.(292 to 228 mm)blowerwheel.
4-IndoorBlowerMotorB3(all units)
All direct-drive LGA/LCAunitsusesingle-phasePSCmotors.
Belt-drive unitsusesingle orthree-phasemotors(same as
supply voltage).
Single-phase Direct-drive 208/230Vmotors
Direct-drivemotorsare equipped withfivespeed tapsfor
adjusting blowerspeed.All motorsare ball bearing type
and useasinglecapacitor (C4)located on the blower
housing.
Single-phase Direct-drive 460Vmotors
All LGA/LCA460Vand 575Vunitsuse a 460Vsingle-phase
PSCblowermotor.The motorhasthree cap-plugs(J38)for
adjusting blowerspeed.All motorsare ball bearing type and
useacapacitor (C4)located on the blowerhousing.
The blowermotorin 575Vunitsusesan auto-transformer(T4)
tostep-down 575Vto 460V.T4islocated inthe blower
compartmentand ispowered atall times.

FIGURE9
STATICPRESSURE
TEST
MANOMETER
LGA/
LCAUNIT
Page 20
F
I
G
U
R
E
8
LGA/LCA SUPPLY
AIR BLOWER
BELT DRIVE SHOWN
BLOWER
DIVIDERPANEL
TRANSITION
BLOWER
MOTOR
MOTOR
BASE BELT
TENSIONER
REMOVE SCREWS(4)TO
REMOVE BLOWER
ADJUSTPULLEY
TOCHANGE SPEED
REMOVE SCREWS(4)TO
REMOVE BLOWER
Three-phase and Single-phase Beltdrive motors
Belt-drive blowermotorsused in LGA/LCAunitsaresingle or
three-phase.Three-phasemotorsdo notuserun capacitors.
Single phasemotor run capacitorsareintegraltothe motor.
Allmotorsaresingle-speedball-bearingtypewhichuse anad-
justable pulleyforadjusting blowerspeed.
5- MotorFuses F27
Blowermotorsin 575Vdirect-drive unitsare protected byline
voltage fuseslocated inthe upperportion of the blower
compartment.
6-BlowerMotorCapacitorC4
All single-phase blowermotorsarePSCtype whichrequire a
run capacitor.Capacitor ratingsmaybe different foreachmo-
tor,but the rating and repairpartnumberwill be printed on the
side of the capacitor.
7-TransformerT4
575(J)voltagedirect-drivevoltageunitsusealinevoltageto
460Vauto-transformerto powerthe indoorblowerand out-
doorfan.Thisautotransformerisalsoconnected directlyto
line voltage and ispowered atall times. It hasamaximum
rating of3.4A.
D-BLOWEROPERATION/ADJUSTMENT
1-BlowerOperation
NOTE-The following isa generalized procedure and doesnotapplyto all
thermostatcontrolsystems.
1-Bloweroperation isdependenton the thermostatcontrol
systemoption thathasbeen installed inthe LGA/LCA
units.Referto operation sequence of the controlsystem
installed fordetailed descriptionsofbloweroperation.
2-Generally,bloweroperation is setat the thermostat fan
switch.Withthe fan switchin“ON”position and the OCP
inputis“ON”,thebloweroperatescontinuously.With
the fan switchin“AUTO”position, the blowercycles
with demand.
3-Inmostcases, the blowerand entire unitwill be off when
the systemswitchisinthe “OFF”position.The onlyex-
ception isimmediatelyaftera heating demand when the
blowercontrolkeepsthe bloweron until all heatisex-
tracted fromthe heatexchanger.
2-TemperatureRise
TemperatureriseforLGA/LCAunitsdependson unitinput,
blowerspeed,blowerhorsepowerand staticpressure as
marked on the unitrating plate.The blowerspeed mustbe
set forunitoperation withinthe range of“AIRTEMP.RISE
°F”listed on the unitrating plate.
To MeasureTemperatureRise:
1-Place plenumthermometersinthesupplyandreturnair
plenums.Locatesupplyairthermometerin horizontal
run of the plenum,closeto unit, yet farenough awayit
will notpick up radiantheat fromthe heatexchanger.
2-Set thermostat to highestsetting.
3-Afterplenumthermometershavereached theirhighest
and steadiestreadings,subtract the returntemperature
fromthe supplytemperature.The differenceshould be
inthe range listed on the unitrating plate. If the tempera-
tureistoo low,decrease blowerspeed. If temperatureis
too high,firstcheckthe firingrate.Providedthe firingrate
isacceptable,increaseblowerspeedtoreducetempera-
ture.
3-ExternalStaticPressure
1-Measuretap locationsas showninfigure 9.
2-Punch a 1/4”diameterhole
insupplyand return airple-
nums. Insertmanometer
hoseflushwithinside edge
ofhole orinsulation.Seal
aroundthehosewithperma-
gum.Connect the zero end
of the manometertothe dis-
charge (supply)side of the system.On ducted sys-
tems,connecttheotherendofmanometertothereturn
ductasabove.
3-With onlythe blower running and the evaporatorcoil
dry,observethe manometer reading.Adjustblower
motorspeed to deliverthe airdesired according tothe
job requirements.
4-Sealaround the holewhen the check is complete.