Lennox CBX25UHV Series Installation And Service Procedure page 14

Before installing the unit, check information on the unit
rating plate to ensure that the unit meets the job
specification, proper electrical power is available, and that
proper duct clearances are maintained.
CAUTION
Physical contact with metal edges and corners while
applying excessive force or rapid motion can result in
personal injury. Be aware of, and use caution when
working near these areas during installation or while
servicing this equipment.
WARNING
Before installing or servicing unit, be sure ALL power to
the unit is OFF. More than one disconnect switch may be
present. Electrical shock can cause personal injury or
death!
NOTE - If installing heat sections at the same time as the air
handler unit, install the electric heat section in the air
handler unit before setting the air handler unit and attaching
the plenum.
1. Shut off all power to the air handler unit. More than one
disconnect may be required.
2. Remove air handler access panel and keep the six
screws to reattach access panel after installing heat
elements.
3. Disconnect any existing field supply wires and pull
them out of the air handler. Disconnect and remove
wiring harness and fastener. If not removed, these
items will prevent the heat section's base from resting
properly in the compartment.
4. Remove the no-heat seal plate in the air handler frame.
5. Slide the electric heat section into the air handler. Be
careful that the heating elements do not rub against the
sheet metal opening when they slide into the air
handler. The side opposite the side with the mounting
holes should slip behind the offset. The mounting holes
should then line up with holes in the air handler control
box.
6. Secure the electric heater assembly with the screws
that were removed from the heat element panel. Install
two field-provided #8 self-drilling, self-taping (SDST)
screws in the front of the electric heater assembly (see
figure 14).
INSTALL 2 FIELD-PROVIDED SCREWS TO SECURE THE
FRONT OF THE HEATER CIRCUIT BREAKER ASSEMBLY TO
THE FRONT FLANGE OF THE AIR HANDLER.
Figure 14. Installing the Heat Element Assembly
7. The air handler access panels have knockouts over the
circuit breaker opening. Knock out both plates to
accommodate the circuit breaker levers. If installing a
heat element assembly with circuit breakers, remove
the knockouts but do not install the access panel until
all electrical connections have been completed.
WARNING
Foil face insulation must be cut to eliminate the possibility
for any frayed foil to coming in contact with any main or
low voltage connections. Insulation must be kept a
minimum of 1/2" away from any electrical connection.
Page 14
INSTALL SCREWS
REMOVED FROM
THE NO-HEAT
SEAL PLATE.