and the wire tie on the right to be cut is located approximately
6 in. down the tube sheet.
Step 5—Select and Install Ductwork
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 ordi-
nances.
Select and size ductwork, supply-air registers, and return air grilles
according to ASHRAE (American Society of Heating, Refrigera-
tion, and Air Conditioning Engineers) recommendations.
The unit has duct flanges on the supply- and return-air openings on
the side of the unit.
When designing and installing ductwork, consider the following:
For vertical supply and return units, tools or parts could drop
into ductwork and cause serious injury or death. Install a 90
degree turn in the return ductwork between the unit and the
conditioned space. If a 90 degree elbow cannot be installed,
then a grille of sufficient strength and density should be
installed to prevent objects from falling into the conditioned
space. Units with electric heaters require 90 degree elbow in
supply duct.
1. All units should have field-supplied filters or accessory filter
rack installed in the return-air side of the unit. Recommended
sizes for filters are shown in Table 1.
2. Avoid abrupt duct size increases and reductions. Abrupt
change in duct size adversely affects air performance.
IMPORTANT: Use flexible connectors between duct-work and
unit to prevent transmission of vibration. Use suitable gaskets to
ensure weather tight and airtight seal. When electric heat is
installed, use fireproof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct. Heat
resistant duct connector (or sheet metal sleeve) must extend 24-in.
from electric heater element.
1. Size ductwork for cooling air quantity (cfm). The minimum
air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities below
those recommended.
2. Seal, insulate and weatherproof all external ductwork. Seal,
insulate and cover with a vapor barrier all ductwork passing
through conditioned spaces. Follow latest Sheet Metal and Air
Conditioning Contractors National Association (SMACNA)
and Air Conditioning Contractors Association (ACCA) mini-
mum installation standards for residential heating and air
conditioning systems.
3. Secure all ducts to building structure. Flash,weatherproof, and
vibration-isolate duct openings in wall or roof according to
good construction practices.
CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE UNITS
Before performing service or maintenance operations on
system, turn off main power to unit. Turn off accessory heater
power switch if applicable. Electrical shock could cause
serious injury or death.
1. Open all electrical disconnects before starting any service
work.
Fig. 5—Unit Leveling Tolerances
C99065
A
B
C
MAXIMUM ALLOWABLE
DIFFERENCE (in.)
A-B B-C A-C
1/4 1/4 1/4
Fig. 6—Slab Mounting Detail
C99096
OPTIONAL
RETURN
AIR
OPENING
OPTIONAL
SUPPLY
AIR
OPENING
INDOOR COIL OUTDOOR COIL
2"
Fig. 7—Threading Belt
C99067
HANDHOLD
FEED
HOOK
UNIT 50JZ MAXIMUM WEIGHT A B
Size lb. kg. in. mm. in. mm.
024 321 145.6 19.0 482.6 18.25 463.6
030 342 155.2 20.0 508 19.25 489
036 350 158.8 20.0 508 19.0 482.6
042 372 168.8 21.0 533.4 20.5 520.7
048 377 171.0 20.0 508 21.25 539.8
060 450 204.2 21.0 533.4 20.0 508.0
Fig. 8—Suggested Rigging
C99075
PLACE RIGGING BRACKET ASSEMBLY IN 4
HAND HOLES AND INSTALL TIE DOWN STRAP
AROUND PERIMETER OF UNIT AND THROUGH
SPACE IN BRACKET ASSEMBLY
INSTALL SAFETY STRAPS TO
RIGGING CLEVIS AT 4 RIGGING BRACKETS
TIGHTEN STRAPPING SECURELY
WITH TENSION BUCKLE
SEE DETAIL A
DETAIL A
SCALE 0.250
914-137"
(36"-54")
“A”
“B”
6
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