Unit Parts Arrangement; I-Unit Components - Lennox LDT Series Information

BLOWERS
ECONOMIZER
DAMPERS
(OPTIONAL)
BLOWER
MOTOR
BLOWER
INVERTER
CONDENSATE
DRAIN
UNIT
CONTROLLER
DISCONNECT
(FACTORY-INSTALLED
OPTION)

I-UNIT COMPONENTS

CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal in­
jury. Take care while handling this equipment and
wear gloves and protective clothing.
All 13 through 20 ton units are configure to order units
(CTO). Unit components are shown in figure 1. All units
come standard with hinged unit panels. The unit panels
may be held open with the door rod located 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 discharge can affect elec­
tronic components. Take precautions to
neutralize
touching your hand and tools to metal
prior to handling the control.
Control box components are shown in figures 3 and 4. The
control box is located in the upper portion of the compressor
compartment.
PARTS ARRANGEMENT
INDOOR
FILTERS
(SIX - 24 X 24 X 2")
8.8.8.8
GAS VALVE
electrostatic charge
COIL
COMBUSTION
BURNERS
AIR INDUCER
FIGURE 1
1-Disconnect Switch S48
Units with higher SCCR rating may be equipped with an
disconnect switch S48. Other factory or field installed
optional 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 mounted
in the control box. Transformer supplies power to control
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
208/230V TRANSFORMER
BLUE
SECONDARY
208 VOLTS
RED
230 VOLTS
PRIMARY
ORANGE
FIGURE 2
by
3-Contactor Transformer T18
T18 is a single line voltage to 24VAC transformer used in all
LDT 13 to 20 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 13
OUTDOOR
OUTDOOR
COILS
COMPRESSORS
shown in figure 2, while
YELLOW
460 (G) and 575 (J)
voltage transformers
use a single primary
voltage tap.
BLACK
FANS