Lennox CBX25UHV Series Installation And Service Procedure page 16

Figure 17. Circuit Breaker Knockouts
C-Electrical Connections
WARNING
Electric shock hazard! - Disconnect all
power supplies before servicing.
Replace all parts and panels before op­
erating.
Failure to do so can result in death or elec­
trical shock.
WARNING
USE COPPER CONDUCTORS ONLY.
NOTE - Refer to the nameplate on the air handler unit for
minimum circuit ampacity and maximum overcurrent
protection size.
The air handler units are provided with openings to be used
with 1-1/2 inch trade size (1-31/32 inch diameter) conduit.
If the installation requires a single point power supply, refer
to the nameplate on the single point power supply
accessory for minimum circuit ampacity and maximum
overcurrent protection size. Select the proper supply circuit
conductors in accordance with tables 310-16 and 310-17 in
the National Electrical Code, ANSI/NFPA No. 70 or tables 1
through 4 in the Canadian Electric Code, Part I, CSA
Standard C22.1.
Refer to figure 37 for typical low voltage field wiring for air
handler/condensing unit and heat pump applications.
Figure 18 is a diagram of the air handler connections and
the heater elements high-voltage wiring.
1. Make wiring connections as follows:
Heaters equipped with circuit breakers—Connect
field power supply wiring to circuit breaker(s). Figure 18
CIRCUIT BREAKERS
CIRCUIT BREAKERS
KNOCKOUTS
AIR HANDLER ACCESS PANEL
shows L1, L2 and ground GND connections for a
2-breaker configuration.
208/240 VOLT FIELD
GND
SUPPLY WIRES
L1
CIRCUIT 1
L2
L1
CIRCUIT 2
L2
Field Supply
Ground Wires
Figure 18. Field Power Supply Wiring
Heaters equipped with terminal blocks—Connect
field power supply wiring to terminal block(s). Figure 19
shows L1, L2 and ground (GND) connection for a
terminal block configuration.
GND
FIELD SUPPLY
GROUND WIRES
Figure 19. Terminal Block Connections
2. Remove the interface harness from the air handler unit
and connect the 6-pin connector on the heater
assembly to the mating connector on the air handler
unit.
D-Circuit Breaker Cover Installation
1. Remove any installed patch plates.
2. Remove paper covering adhesive back around
backside perimeter of circuit breaker cover (figure 20).
3. Position the breaker cover over the air handler circuit
breaker opening (figure 21).
CIRCUIT BREAKER COVER
Figure 20. Remove Paper Cover
Page 16
L2
208/240 VOLT FIELD
SUPPLY WIRES
L1
(BACKSIDE)
REMOVE PAPER
COVERING
STICK BACK