Carrier OMNIZONE 50XCA06-24 - Manual (Page 34)

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Indoor Self-Contained Air-Cooled Unit
Constant Volume Application
HVAC Guide Specifications
Size Range: 5 to 20 Tons
Carrier Model Number: 50XCA
Part 1 — General
1.01 SYSTEM DESCRIPTION
Indoor packaged vertical air-cooled cooling unit
using hermetic scroll compressors and built-in con-
denser fan for cooling duty. Unit shall discharge sup-
ply air vertically or horizontally and condenser air
horizontally as shown on contract drawings.
1.02 QUALITY ASSURANCE
A. Units shall be rated in accordance with AHRI Stan-
dard 340/360, latest edition, as appropriate.
B. Unit shall be designed to conform to ANSI/
ASHRAE 15, latest revision safety code, and UL
Standard 1995, and shall be UL listed under both
American and Canadian Standards.
C. Unit shall be built in an ISO 9001:2000 certified
manufacturing facility and shall be fully run-tested.
D. Insulation, adhesive, and liner system shall meet
NFPA 90A requirements for flame spread and
smoke generation.
1.03 DELIVERY, STORAGE, AND HANDLING
Units shall be stored and handled according to man-
ufacturer’s recommendations.
Part 2 — Products
2.01 EQUIPMENT
A. General:
Factory-assembled, single-piece, air-cooled cooling
unit. Unit shall consist of scroll refrigerant compres-
sor(s), indoor fan section with belt drive centrifugal
fans and motor, evaporator coil section with direct
expansion coil and drain pan, air-cooled condenser
fan section with belt drive centrifugal fans and
motor, factory wiring, piping and controls, and a
system charge of refrigerant (R-410A). Unit may be
used with or without return ductwork.
B. Unit Cabinet:
1. Cabinet shall be constructed of minimum 18
gage zinc surface alloyed steel with a baked
enamel finish. Unit shall be capable of with-
standing ASTM B117 500-hour salt spray test.
2. Cabinet shall be fully insulated.
3. Unit drain pan shall have positive double slope
to the drain to prevent standing water in pan.
4. Panels for servicing shall be easily removable.
C. Evaporator Fan Section:
1. Fans shall be double inlet, centrifugal wheel
with forward curved blades designed for contin-
uous operation. Fan wheel and scroll shall be
constructed of steel with corrosion resistant fin-
ish, and statically and dynamically balanced.
2. Fan shall be belt drive with an adjustable pitch
motor pulley and fixed pitch fan pulley, with
permanently lubricated ball-bearing type bear-
ings. Units larger than 12 tons use pillow block
bearings.
3. Motor shall be 3-phase high-efficiency NEMA
frame TEFC (totally enclosed fan cooled) of the
same voltage as the compressor(s). Motor shall
have permanently lubricated ball bearings.
D. Compressor:
Hermetic scroll compressors shall be internally pro-
tected with high pressure relief. Compressors shall
be factory rubber shock mounted with internal
spring vibration isolators.
E. Coils:
1. Evaporator and condenser coil shall have alumi-
num plate fins mechanically bonded to seamless
copper tubes with all joints brazed. Tube sheet
openings shall be swaged to prevent tube wear.
Coils shall be face split design.
2. Direct expansion coil shall be designed and
tested in accordance with ANSI/ASHRAE 15,
latest revision safety code.
3. Coil and drain pan shall be accessible through
service access panels for cleaning.
F. Filter:
Filter frame shall be installed upstream of the cool-
ing coil, designed to take a 1-in. or 2-in. thick clean-
able or disposable type commercially available filter.
Filters shall be accessible from either side of the unit
and filter rack shall be usable with ducted or free
return. Disposable filters will be supplied with the
unit.
G. Condenser:
1. Fans shall be double inlet, centrifugal wheel
with forward curved blades designed for contin-
uous operation. Fan wheel and scroll shall be
constructed of steel with corrosion resistant fin-
ish, and statically and dynamically balanced.
2. Fan shall be belt drive with an adjustable pitch
motor pulley and fixed pitch fan pulley, with
permanently lubricated, ball-bearing type bear-
ings. Units larger than 12 tons use pillow block
bearings.
3. Motor shall be 3-phase high-efficiency NEMA
frame TEFC (totally enclosed fan cooled) of the
same voltage as the compressor(s). Motor shall
have permanently lubricated ball bearings.
H. Operating Characteristics:
Unit shall be capable of providing a constant volume
of conditioned air at a specified static pressure
within the unit’s normal operating range. Unit shall
have dual-stage cooling capacity control on all units
sizes 12 to 24. Each compressor shall be on an
independent refrigerant circuit. Unit shall be capable
of starting and operating at up to 115 F outdoor
Guide specifications