Carrier 48SS - Manual (Page 25)

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Packaged Heating/Cooling Units
Constant Volume Application
HVAC Guide Specifications
Size Range: I V 2 to 5 Tons, Nominal Cooling
40,000 to 140,000 Btuh,
Nominal Input Heating
Carrier Model Number 48SS
Part 1 — General
1 01 SYSTEM DESCRIPTION
A Outdoor rooftop mounted, gas heating/electric cool­
ing unit utilizing a rotary, reciprocating, or scroll her­
metic compressor for cooling duty Unit shall discharge
supply air downward or horizontally as shown on con­
tract drawings Outdoor fan/coil section shall have a
blow-thru design for minimum sound levels.
1 02 QUALITY ASSURANCE
A Unit shall be rated in accordance with ARl Standards
210/240-89 and 270-84
B Unit shall be designed in accordance with UL Stand­
ard 564.
C Unit shall be UL listed and CSA certified as a total
package for safety requirements
D Roof curb shall be designed to conform to NRCA
Standards
E Insulation and adhesive shall meet NFPA 90A re­
quirements for flame spread and smoke generation
F Cabinet insulation shall meet ASHRE standard
no 62P
1 03 DELIVERY, STORAGE, AND HANDLING
A Unit shall be stored and handled per manufacturer’s
recommendations
Part 2 — Products
2 01 EQUIPMENT
A General
Factory-assembled, single-piece heating and cooling
unit Contained within the enclosure shall be all fac­
tory wiring, piping, controls, refrigerant charge (R-22),
and special features required prior to field start-up
B Unit Cabinet'
1 Unit cabinet shall be constructed of phosphated,
zinc-coated prepainted steel, capable of withstand­
ing 500 hours in salt spray
2 Cabinet panels shall be easily removed for
servicing
3 Indoor blower compartment interior cabinet sur­
faces shall be insulated with a minimum Vz-in. thick,
flexible fiberglass insulation, coated on the air side.
Aluminum foil-faced fiberglass insulation shall be
used in the entire section
C. Fans.
1 The indoor (evaporator) fan shall be 2- or 3-speed
direct-drive, as shown on equipment drawings
2 Fan wheel shall be made from steel, be double­
inlet type with forward curved blades with corro­
sion resistant finish and be dynamically balanced.
3 Outdoor (condenser) fan shall be of the direct driven,
propeller type with aluminum blades riveted to cor­
rosion resistant steel spiders, be dynamically bal­
anced, and discharge air vertically upwards and
horizontally
D Compressor:
1 Fully hermetic compressor with factory-installed vi­
bration isolation
2 Rotary compressors shall be standard on unit size
018 Reciprocating compressors shall be standard
on unit sizes 024-042 Scroll compressors shall be
standard on unit sizes 048 and 060.
E Coils
Evaporator and condenser coils shall have aluminum
plate fins mechanically bonded to seamless copper
tubes with all joints brazed Tube sheet openings shall
be belled to prevent tube wear.
F Heating Section.
1 Induced-draft combustion type with energy saving
direct spark ignition system and redundant main
gas valve
2. Induced-draft motors shall be provided with solid-
state hall effects sensor to ensure adequate airflow
for combustion
3 The heat exchangers shall be constructed of alu­
minized steel for corrosion resistance
4 Burners shall be of the in-shot type constructed of
aluminum coated steel
5 Integrated gas control board shall provide control
of heating and simplify troubleshooting through its
built-in diagnostic function.
6. All gas piping and electric power shall enter the unit
cabinet at a single location
G. Refrigerant Components-
Refrigerant components shall be of the Acutrol”' feed
system type
H. Filter section shall consist of field-installed, throw­
away, 1-in. thick fiberglass filters of commercially avail­
able sizes
I. Controls and Safeties
1 Unit Controls.
a Unit shall be complete with self-contained low-
voltage control circuit.
2 Safeties.
Compressors shall incorporate a solid-state com­
pressor protector which provides reset capability
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