Instruction manual

Page 7 of 18Issue 1234507120-01
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.
IMPORTANT
Typical Main and Overflow Drain
Figure 9
ABOVE
FINISHED
SPACE?
overflow DRAIN LINE
ALWAYS RUN AN overflow DRAIN LINE. IF NOT POSSIBLE TO
ROUTE overflow DRAIN LINE, INSTALL low voltage
overflow SWITCH kit. WIRE kit TO SHUT DOWN
COMPRESSOR PER INSTRUCTIONS.
NO
YES
ALLIED
#
X3169
CLEAN OUT
VENT
PRESS IN
(DO NOT GLUE)
VENT MUST EXTEND
ABOVE HEIGHT OF
COIL DRAIN PAN BY
TWO INCHES (51MM)
1” x 3/4” x 3/4”
REDUCING
TEE WITH
PLUG
Lennox1 p-
trap
49p66, J-
TRAP #
91P90 or any
PVC SCH 40 P-
or
J-Trap 3/4”
OVERFLOW
drain
air handler 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).
DRAIN LINE SHOULD
SLOPE A MINIMUM OF
ONE INCH PER 10
FEET (25MM PER 3
METERS)
NOTE
—
WHEN A air handler IS LOCATED
ABOVE a FINISHED SPACE the secondary
drain pan must have a larger footprint
than the air handler.
2 pipe niPPle provided in bag assembly - Sch 80, 3/4” I. D. x 5” - 34K7401 (1): Cut the pipe in half and use it to route the main drain.
1 ALLIED p-tRAP 49p66 REQUIRES A LARGER INSTALLATION SPACE than the j-tRAP 91P90.