Lennox International Inc Lennox Air Handler Condensate Drain, Overflow Drain Line

HORIZONTAL RIGHT

HORIZONTAL LEFT	REMOVE 2 SCREWS
(FACTORY DEFAULT)	SECURING BLOW OFF
	PREVENTION BRACKET

ROTATE BRACKET TO THIS

POSITION AND REINSTALL

Figure 8. Blow-Off Prevention Plate

Condensate Drain

IMPORTANT

On units of this type, where the blower “draws” rather than “blows” air through the coil, traps must be installed in the con­ densate drain lines (primary and auxiliary, if used). Traps prevent the blower from drawing air through the drain lines into the air supply.

ABOVE

FINISHED

SPACE?

NO

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.

LENNOX #

X3169

COMPACT OVERFLOW SWITCH WITH 3/4” FEMALE SLIP INLET AND MALE ADAPTER, TWO PART DESIGN FOR USE WHERE OBSTRUCTIONS PREVENT DIRECT THREADING

	VENT MUST EXTEND
		ABOVE HEIGHT OF
		COIL DRAIN PAN BY
	TWO INCHES (51MM)		VENT
	CLEAN OUT
	PRESS IN
(DO NOT GLUE)

AIR HANDLER DRAIN PAN	MAIN	1” X 3/4” X 3/4”
	DRAIN	REDUCING
OVERFLOW		TEE WITH
		PLUG
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:

SCONNECTED TO SECONDARY DRAIN PAN OR

SCONNECTED TO THE OVERFLOW DRAIN OUTLET OF THE AIR HANDLER DRAIN PAN.

LENNOX1 P-TRAP

49P66, J-TRAP #

91P90 OR ANY

PVC SCH 40 P- OR

J-TRAP 3/4”2” (51MM)

TRAPS MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES — GENERALLY, TWO INCHES (51MM).

1LENNOX P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.

2PIPE 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.

TRAP DEPTH		TO APPROVED
		DRAIN
FOR NEGATIVE PRESSURE COILS (BLOWER	DRAIN LINE SHOULD
AFTER COIL) TRAPS ARE REQUIRED ON ALL
	SLOPE A MINIMUM OF
DRAIN LINES CONNECTED TO COIL.
	ONE	INCH	PER	10
	FEET	(25MM	PER	3
	METERS)

Figure 9. Typical Main and Overflow Drain

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