Condensate Drain - Lennox Merit CBA25UHE Installation Instructions Manual

Condensate Drain

On units of this type, where the blower "draws" rather than "blows" air through the coil, traps must be installed in the
condensate drain lines (primary and auxiliary, if used). Traps prevent the blower from drawing air through the drain lines
into the air supply.
ABOVE
ALWAYS RUN AN OVERFLOW DRAIN LINE. IF NOT POSSIBLE TO
FINISHED
ROUTE OVERFLOW DRAIN LINE, INSTALL LOW VOLTAGE
SPACE?
OVERFLOW
COMPRESSOR PER INSTRUCTIONS.
COMPACT OVERFLOW SWITCH WITH 3/4" FEMALE SLIP INLET
NO
AND MALE ADAPTER, TWO PART DESIGN FOR USE WHERE
OBSTRUCTIONS PREVENT DIRECT THREADING
OVERFLOW
DRAIN
YES
NOTE — WHEN A AIR HANDLER IS LOCATED
ABOVE A FINISHED SPACE THE SECONDARY
DRAIN PAN MUST HAVE A LARGER FOOTPRINT
THAN THE AIR HANDLER.
SECONDARY
DRAIN PAN
WHEN A COIL IS LOCATED ABOVE A FINISHED SPACE, A
3/4" (19.1MM) SECONDARY DRAIN LINE MUST BE:
CONNECTED TO SECONDARY DRAIN PAN
OR
CONNECTED TO THE OVERFLOW DRAIN OUTLET OF
THE AIR HANDLER DRAIN PAN.
TRAPS MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES —
GENERALLY, TWO INCHES (51MM).
1
LENNOX P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.
IMPORTANT
A field-fabricated secondary drain pan, with a drain pipe
to the outside of the building, is required in all installations
over a finished living space or in any area that may be
damaged by overflow from the main drain pan. In some
localities, local codes may require a secondary drain
pan for any horizontal installation.
SLOPING THE UNIT
Make sure the unit is sloped (similar to the slope shown in
figure 7) so that the drain pan will empty completely with-
out water standing in the pan.
IMPORTANT
OVERFLOW DRAIN LINE
SWITCH KIT. WIRE KIT TO
LENNOX #
X3169
MAIN
AIR HANDLER DRAIN PAN
DRAIN
FIGURE 6. Typical Main and Overflow Drain
VENT MUST EXTEND
SHUT DOWN
ABOVE HEIGHT OF
COIL DRAIN PAN BY
TWO INCHES (51MM)
CLEAN OUT
PRESS IN
(DO NOT GLUE)
1" X 3/4" X 3/4"
LENNOX
49P66, J-TRAP #
91P90 OR ANY
PVC SCH 40 P- OR
J-TRAP 3/4"
FOR NEGATIVE PRESSURE COILS (BLOWER
AFTER COIL) TRAPS ARE REQUIRED ON ALL
DRAIN LINES CONNECTED TO COIL.
THIS CORNER SHOULD BE 5/8" (+/- 1/8") HIGHER
THAN DRAIN CORNER
DRAIN CORNER
FIGURE 7. Sloping the Unit for Proper Drainage
Page 8
VENT
REDUCING
TEE WITH
PLUG
1
P-TRAP
2"
(51MM)
TRAP DEPTH
DRAIN LINE SHOULD
SLOPE A MINIMUM OF
ONE INCH PER 10
FEET (25MM PER 3
METERS)
TO APPROVED
DRAIN