Instruction manual

8. Position lifting point directly over the unit’s center of
gravity.
9. Lift unit. When unit is directly over the roof curb, remove
the 2 safety straps. Lower the equipment onto the roof curb.
10. After the unit is placed on the roofcurb or mounting pad,
remove the top crating. On 602B060 units only, 2 wire ties
fastened to the outdoor coils and reversing
valve/accumulator assembly must be cut. Remove the left
and front louver panels and corner post to access wire ties.
The wire tie to be cut on the left is located approximately 4
in. down the tube sheet. The wire tie to be cut on the right
is located approximately 6 in. down the tube sheet.
V. 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:
WARNING: 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 ductwork 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.
3. 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.
4. 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) minimum installation standards for residential
heating and air conditioning systems.
5. Secure all ducts to building structure. Flash, weatherproof,
and vibration-isolate duct openings in wall or roof accord-
ing to good construction practices.
A. CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE UNITS
WARNING: 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.
2. Remove horizontal duct covers to access bottom return and
supply knock out panels.
Fig. 4—Corner Weights
CORNER WEIGHTS (SMALL CABINET) CORNER WEIGHTS (LARGE CABINET)
Model 602B
Unit 24 30 36
Model 602B
Unit 42 48 60
Total Weight 299 320 328 Total Weight 350 355 428
Corner Weight 1 63 63 64 Corner Weight 1 75 76 92
Corner Weight 2 62 74 76 Corner Weight 2 49 50 60
Corner Weight 3 56 56 58 Corner Weight 3 95 96 116
Corner Weight 4 118 127 130 Corner Weight 4 131 133 160
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