I-Unit Components - Lennox LGH Series Unit Information

ECONOMIZER
DAMPERS (OPTIONAL)
BLOWERS
UNIT
CONTROLLER
INVERTER
(OPTIONAL)
CONDENSATE
DRAIN
DISCONNECT
(Factory-installed option)

I-UNIT COMPONENTS

CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and
wear gloves and protective clothing.
All 13 through 25 ton (45.7 through 88 kW) units are con-
figure to order units (CTO). Unit components are shown in
figures 1. All units come standard with hinged unit panels.
The unit panels may be held open with the door rod locat-
ed inside the unit. All L1, L2 and L3 wiring is color coded;
L1 is red, L2 is yellow and L3 is blue.
A-Control Box Components
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic
electronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
Control box components are shown in figure 3. The con-
tro box is located in the upper portion of the compressor
compartment.
PARTS ARRANGEMENT
(LGH180H SHOWN)
EVAPORATOR
FILTERS
COIL
(SIX - 24 X 24 X 2")
GAS VALVE
discharge can affect
(4 ON 180U, 240H/U &
COMBUSTION
AIR INDUCER
BURNERS
FIGURE 1
1-Disconnect Switch S48
Units with higher SCCR rating may be equipped with an
disconnect switch S48. Other factory or field installed op-
tional circuit breakers may be used, such as CB10. S48
and CB10 are toggle or twist-style switches, which can
be used by the service technician to disconnect power to
the unit.
2-Control Transformer T1
All use a single line voltage to 24VAC transformer mount-
ed in the control box. Transformer supplies power to con-
trol circuits in the unit. The transformer is rated at 70VA
and is protected by a 3.5 amp circuit breaker (CB8). The
208/230 (Y) voltage transformers use two primary voltage
taps as shown in figure 2, while 460 (G) and 575 (J) volt-
age transformers use a single primary voltage tap.
208/230V TRANSFORMER
3-Contactor Transformer T18
T18 is a single line voltage to 24VAC transformer used in
all LGH 13 to 25 ton units. Transformer T18 is protected
by a 3.5 amp circuit breaker (CB18). T18 is identical to
transformer T1. The transformer supplies 24VAC power to
the contactors.
Page 23
CONDENSER FANS
(3 FANS ON 156 UNITS; 6
FANS ON 180U, 210, 240H/U,
& 300S/U UNITS
CONDENSER
COILS
OUTDOOR FAN CAPACITORS
(TRANSFORMERS FOR 180U
and 240U, 240V & 575V UNITS)
COMPRESSORS
300S UNITS)
BLUE YELLOW
SECONDARY
208 VOLTS
RED
230 VOLTS
PRIMARY
ORANGE BLACK
FIGURE 2