Johnson Controls YORK Tempo YLAA Series, Installation Operation & Maintenance

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FORM 150.72-NM1 (1020)
19
JOHNSON CONTROLS
2
SECTION 2 – PRODUCT DESCRIPTION
INTRODUCTION
YORK YLAA Air-Cooled Scroll Chillers provide
chilled water for all air conditioning applications using
central station air handling or terminal units. They are
completely self-contained and are designed for outdoor
(roof or ground level) installation. Each complete
packaged unit includes hermetic scroll compressors,
a liquid cooler, air cooled condenser, a charge of Zero
Ozone Depletion Potential Refrigerant R-410A and
a weather resistant microprocessor control center, all
mounted on a pressed steel base.
The units are completely assembled with all
interconnecting refrigerant piping and internal wiring,
ready for field installation.
Prior to delivery, the packaged unit is pressure-tested,
evacuated, and fully charged with Refrigerant-R410A
and oil. After assembly, a complete operational test is
performed with water flowing through the cooler to
assure that the refrigeration circuit operates correctly.
The unit structure is heavy-gauge, galvanized steel. This
galvanized steel is coated with baked-on powder paint,
which, when subjected to ASTM B117 1000 hour, salt
spray testing, yields a minimum ASTM 1654 rating of
“6”. Units are designed in accordance with NFPA 70
(National Electric Code), ASHRAE/ANSI 15 Safety
code for mechanical refrigeration, ASME, and rated in
accordance with ARI Standard 550/590.
GENERAL SYSTEM DESCRIPTION
Compressors
The chiller has suction-gas cooled, hermetic, scroll
compressors. The YLAA compressors incorporate
a compliant scroll design in both the axial and
radial direction. All rotating parts are statically and
dynamically balanced. A large internal volume and oil
reservoir provides greater liquid tolerance. Compressor
crankcase heaters are also included for extra protection
against liquid migration.
Cooler (Evaporator)
The cooler is a direct expansion type with refrigerant
inside high efficiency copper tubes. The liquid flowing
through the cooler is forced over the tubes by water
baffles.
The Water baffles are constructed of brass to resist
corrosion. The removable heads allow access to the
internally enhanced, seamless copper tubes. Vent and
drain connections are included.
Water inlet and outlet connections are grooved for
compatibility with field supplied ANSI/AWWA C-606
couplings.
The cooler is equipped with a heater controlled by
a separate thermostat. The heater provides freeze
protection for the cooler down to -20º F (-29º C) ambient.
The cooler is covered with ¾” flexible, closed cell, foam
insulation (K = 0.25).
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