Page 9
CBX32MV SERIES
7. Set the unit so that it is level. Using sheet metal
screws, connect the return and supply air plenums as
required.
NOTE − For downflow application, metal or class I supply
and return air plenums must be used.
COMBUSTIBLE FLOOR
ADDITIVE BASE
PROPERLY SIZED
FLOOR OPENING
AIR
HANDER
UNIT
Figure 9. Downflow Combustible Flooring Base
8. For downflow installation on combustible flooring, an
additive base must be used as illustrated in figure 9 on
page 9.
See CBX32MV Engineering Handbook for
downlfow combustible flooring base kits available for
this air handler
.
9. Cut an opening appropriately sized for combustible
base. Base dimensions are illustrated in figure 10.
After opening has been cut, set the additive base into
opening. Connect outlet air plenum to the additive
base. Set the unit on the additive base so flanges of
the unit drop into the base opening and seal against
the insulation strips. The unit is now locked in place.
Install return air plenum and secure with sheet metal
screws.
TOP VIEW
OPENING
1-5/8 (41)
SIDE VIEW
1-5/8 (41)
11-3/8
(289)
2 (51)
1-5/8 (41)
24 (610) −068 ONLY
22-1/8 (562) OTHER MODELS
5/8 (16)
13-3/8 (340)
SUPPLY AIR OPENING
INCHES (MM)
−018/−024 08−1/4 (464)
−024/−030 and up 23−1/4 (591)
−018/−024 15
(381)
−024/−030 AND
UP 20 (508)
Figure 10. Downflow Combustible Base Dimensions
Brazing Connections
WARNING
Polyol ester (POE) oils used with HFC−410A
refrigerant absorb moisture very quickly. It is very
important that the refrigerant system be kept closed as
much as possible. DO NOT remove line set caps or
service valve stub caps until you are ready to make
connections.
WARNING
Danger of fire. Bleeding the refrigerant
charge from only the high side may result
in the low side shell and suction tubing
being pressurized. Application of a
brazing torch while pressurized may
result in ignition of the refrigerant and oil
mixture − check the high and low
pressures before unbrazing.
WARNING
When using a high pressure gas such as
dry nitrogen to pressurize a refrigeration
or air conditioning system, use a
regulator that can control the pressure
down to 1 or 2 psig (6.9 to 13.8 kPa).
CAUTION
Brazing alloys and flux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing
operations. Perform operations only in well ventilated
areas.
Wear gloves and protective goggles or face shield to
protect against burns.
Wash hands with soap and water after handling brazing
alloys and flux.
IMPORTANT
To prevent the build up of high levels of nitrogen when
purging, be sure it is done in a well ventilated area. Purge
low pressure nitrogen (1 to 2 psig) through the refrigerant
piping during brazing. This will help to prevent oxidation
and the introduction of moisture into a system.
