8
CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE UNITS
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn of f main
power to system and tag lockout. There may be more than
one disconnect switch. Turn off accessory heater power
switch if applicable.
!
WARNING
1. Open all electrical disconnects and install lockout tag before
starting any service work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)
3. Starting in a corner as shown in Fig. 9, score the panel in
both directions from the corner. Tap the panel out from the
scored corner using a small hammer. Be careful and not
damage any other part of the unit.
4. If the unit ductwork is to be attached to vertical opening
flanges on the unit base (jackstand applications only), do so
at this time.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in property
damage.
Collect ALL screws that were removed. Do not leave
screws on rooftop as permanent damage to the roof may
occur .
!
WARNING
5. It is recommended that the base insulation around the peri-
meter of the vertical return--air opening be secured to the
base with aluminum tape. Applicable local codes may
require aluminum tape to prevent exposed fiberglass.
6. Reinstall both horizontal duct covers. Ensure opening is
air-- and watertight.
7. After completing unit conversion, perform all safety checks
and power up unit.
NOTE: The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of non
residence--type air conditioning and ventilating systems, NFPA
90A or residence--type, NFPA 90B; and/or local codes and
ordinances.
Step 6 — Provide for Condensate Disposal
NOTE: Ensure that condensate water disposal methods comply
with local codes, restrictions, and practices.
The units dispose of condensate through a 3/4 -- in. NPT female
fitting that exits on the compressor end of the unit. Condensate
water can be drained directly onto the roof in rooftop installations
(where permitted) or onto a gravel apron in ground level
installations. Install a field-- supplied condensate trap at end of
condensate connection to ensure proper drainage. Make sure that
the outlet of the trap is at least 1 in. (25 mm) lower than the
drain--pan condensate connection to prevent the pan from
overflowing. Prime the trap with water. When using a gravel apron,
make sure it slopes away from the unit.
If the installation requires draining the condensate water away from
the unit, install a field--supplied 2--in. (51 mm) trap at the
condensate connection to ensure proper drainage. Condensate trap
is available as an accessory or is field--supplied. Make sure that the
outlet of the trap is at least 1 in. (25 mm) lower than the unit
drain--pan condensate connection to prevent the pan from
overflowing. Connect a drain tube using a minimum of
field--supplied 3/4 -- in. PVC or field-- supplied 3/4 --in. copper pipe
at outlet end of the 2 -- in. (51 mm) trap (See Fig. 10). Do not
undersize the tube. Pitch the drain trough downward at a slope of at
least 1 in. (25 mm) for every 10 ft. (3.1 m) of horizontal run. Be
sure to check the drain tube for leaks. Prime the trap at the
beginning of the cooling season start--up.
Horizontal Duct Covers
A09076
Basepan
Downflow
(Vertical)
Supply
Knockout
Basepan
Downflow
(Vertical)
Return
Knockout
A09093
Fig. 8 -- Supply and Return Duct Opening
1
2
2
1
3
3
4
4
1. Score groove in corner 1 in both directions as far as you can reach.
2. Starting in corner 1, tap-out all sides with a small hammer. Be careful
not to damage any other part of unit.
3. If side from corner 3 to 4 is not accessible due to heat exchanger,
pivot panel up and down by hand until remaining side breaks off.
INSTRUCTIONS FOR REMOVING DOWNSHOT PANELS
A09054
Fig. 9 -- Vertical (Downflow) Discharge Duct Knockouts
50XT--A
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