Instruction Manual

507792-01G / 31-5000700 Issue 2217 Page 7 of 8
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
CLEAN OUT
VENT
PRESS IN
(DO NOT GLUE)
VENT MUST EXTEND
ABOVE HEIGHT OF
COIL DRAIN PAN BY
TWO INCHES
1” X 3/4” X 3/4”
REDUCING
TEE WITH
PLUG
PVC
SCH 40 P- OR
J-TRAP 3/4”
OVERFLOW
DRAIN
OPTIONAL
SAFETY
PAN
COIL DRAIN PAN
WHEN A COIL IS LOCATED ABOVE A FINISHED SPACE, A 3/4” 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.
DRAIN LINE SHOULD
SLOPE A MINIMUM OF
ONE INCH PER 10 FT.
NOTE — WHEN A AIR HANDLER IS LOCATED ABOVE A FINISHED SPACE THE SECONDARY
DRAIN PAN MUST HAVE A LARGER FOOTPRINT THAN THE AIR HANDLER.
MAIN
DRAIN
TO APPROVED
DRAIN
FOR NEGATIVE PRESSURE COILS (BLOWER
AFTER COIL) TRAPS ARE REQUIRED ON ALL
DRAIN LINES CONNECTED TO COIL.
COMPACT OVERFLOW SWITCH WITH 3/4” FEMALE SLIP INLET
AND MALE ADAPTER, TWO PART DESIGN FOR USE WHERE
OBSTRUCTIONS PREVENT DIRECT THREADING
SECONDARY
DRAIN PAN
2”
(51MM)
TRAP DEPTH
Figure 7. Typical Main and Overow Drain Installations
Take care when drilling test holes into the furnace ange
and the duct. Drill holes away from refrigerant piping.
Test holes should be drilled where specied in order to
avoid unit damage.
CAUTION
Proper air volume must be provided over the evaporator
coil. Select a blower motor speed tap that will provide 400
± 50 CFM per 12,000 Btuh of cooling capacity (wet coil). A
static pressure reading must be taken to see if the pressure
drop falls within the proper range. See Table 2.
To ensure accuracy, air must be read from below the coil
and above the coil. See Figure 6 for an example to obtain
an accurate reading.
1. Drill one 5/16” air test hole into the delta plate between
the coil slabs.
2. Drill one 5/16” air test hole into the duct above the top
of the coil.
3. Connect the instrument for static pressure
measurement hoses to the air entering side of coil.
Insert the hoses so that 1/4” extends inside the duct or
end seal. Seal around holes with Permagum®.
4. Turn on electrical power to the furnace and set the
thermostat to initiate a cooling demand.
5. Table 2 lists air volumes and equivalent static pressure
readings for these units. Observe the static pressure
reading. If the reading is below the required air
volume, increase the blower speed; if the reading is
above the required air volume, decrease the blower
speed. Refer to the furnace wiring diagram for blower
speed settings.
6. When the required static pressure readings are
obtained, remove the test hose lines and insert snap
hole plugs into test holes.