York 28971AR Refrigerator User Manual


 
YORK INTERNATIONAL
4
Specifications
These YORK air cooled chillers are shipped as a com-
plete factory package. Each unit is completely as-
sembled with all interconnecting refrigerant piping and
internal wiring, ready for field installation:
COMPLETE FACTORY PACKAGE
Each compressor is installed on its own indepen-
dent refrigerant circuit, which is factory pressure
tested, evacuated, then fully charged with refriger-
ant and oil.
After assembly, an operational test is performed with
water flowing through the cooler to ensure each cir-
cuit operates correctly.
Cabinet and base frame are constructed of formed
heavy gauge, galvanized steel.
All external structural parts are covered with archi-
tecturally neutral Desert Sand (Munsell #10YR6-
2) baked-on enamel powder paint. This provides a
finish which, when subjected to ASTM B117, 500
hour, 5% salt spray conditions, shows breakdown
of less than
1
/
8
" either side of a scribed line (equiva-
lent to ASTM D1654 rating of 6).
Design is in accordance with applicable sections of
ASME Pressure Vessel Code, NFPA 70 (National
Electrical Code), U.L. and cU.L. Standards , and
ASHRAE/ANSI-15 Safety Code for Mechanical Re-
frigeration.
Units are Rated and Certified in accordance with
ARI Standard 550/590-98.
All exposed power wiring routed through liquid-tight,
non-metallic conduit.
SEMI-HERMETIC YORK SCREW COMPRESSORS
An ideal synergy of expertise, sister division YORK
Refrigeration Compressor Engineers as integral
members on YORK Engineered Systems Chiller De-
sign Team, has resulted in a world class compressor
with unequaled performance.
Continuous function, microprocessor controlled, 3-
way proportional Capacity Control Valve provides
regulated output pressure independent of valve input
pressure for a stable, smooth, and precise match of
compressor capacity to cooling load to 10% of chiller
capacity.
Automatic spring return of capacity control valve to
minimum load position ensures compressor starting
at minimum motor load. Internal discharge check to
prevent rotor backspin upon shut-down.
Acoustically tuned, internal discharge gas muffler
eliminates objectionable noise at the source, while
optimizing flow for maximum performance.
Reliable suction gas cooled, high efficiency, acces-
sible hermetic motor with APT2000 type magnet wire
and redundant overload protection using both ther-
mistor and current overload protection.
Suction gas screen and serviceable, 0.5 micron full
flow oil filter within the compressor housing.
Some models equipped with tuned port economizer
as appropriate for enhanced capacity and superior
efficiency.
Cast iron compressor housing precisely machined for
optimal clearances and superb efficiency. Entire com-
pressor, from suction to discharge has a Design
Working Pressure of 450 PSIG (31 bar).
350W compressor body cartridge heater.
CONDENSER SECTION
Condenser Fans with low noise, full airfoil cross sec-
tion for maximum efficiency, statically and dynami-
cally balanced for low vibration operation, and posi-
tioned in extended, formed steel orifices for low sound
and maximum efficiency.
Condenser fan motors are high efficiency, direct drive,
6-pole, 3-phase, Class-F, current overload pro-
tected, totally enclosed (TEAO) type with double
sealed, permanently lubricated, ball bearings.
Fin and tube condenser coils of seamless, internally
enhanced, high condensing coefficient, corrosion re-
sistant copper tubes arranged in staggered rows and
mechanically bonded to corrosion resistant aluminum
alloy fins with full height fin collars. Design working
pressure is 450 PSIG (31 bar).
EVAPORATOR
High efficiency, direct-expansion type cooler with re-
frigerant in tubes and chilled liquid through the baffled
shell. Independent circuits provided for each com-
pressor.
Design working pressure of the shell waterside is
150 PSIG (10.3 bar), and 350 PSIG (24 bar) for the
refrigerant side. Constructed and tested in accor-
dance with applicable sections of ASME Pressure
Vessel Code, Section VIII, Division (1). Water side
exempt per paragraph U-1, (c), (6). Other codes,
such as German TÜV, also available for global cus-
tomers.
Water baffles fabricated from galvanized steel to
resist corrosion. Removable heads allow access to
internally-enhanced, seamless, copper tubes. Wa-
ter vent and drain connections included.
Cooler equipped with thermostatically controlled
heater for protection to -20°F (-29°C) ambient, and
insulated with ¾" (19mm) flexible, closed-cell foam
(k = 0.25).