York YCAS0098EB, Installation Operation & Maintenance, Page: 15 / 184

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JOHNSON CONTROLS
FORM 201.18-NM7
INTRODUCTION
YORK YCAS chillers are designed for water or wa-
ter-glycol cooling. All units are designed to be located
outside on the roof of a building or at ground level.
The units are completely assembled with all intercon-
necting refrigerant piping and internal wiring, ready for
field installation.
Prior to delivery, the unit is pressure tested, evacuated,
and fully charged with refrigerant and oil in each of the
two independent refrigerant circuits. After assembly,
an operational test is performed with water flowing
through the cooler to ensure that each refrigerant circuit
operates correctly.
The unit structure is manufactured from heavy gauge,
galvanized steel. All external structural parts are coated
with “Desert Sand” 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 (equivalent
to ASTM D1654 rating of “6”).
All exposed power wiring is be routed through liq-
uid-tight, non-metallic conduit.
General Description
The Air Cooled Screw Chiller utilizes many components
which are the same or nearly the same as a standard
reciprocating chiller of a similar size. This includes
modular frame rails, condenser, fans and evaporator.
The chiller consists of 2 screw compressors in a corre-
sponding number of separate refrigerant circuits, a single
shell and tube DX counterflow evaporator, economizers,
an air cooled condenser, and expansion valves.
Compressor
The semi-hermetic rotary twin-screw compressor is
designed for industrial refrigeration applications and
ensures high operational efficiencies and reliable per -
formance. Capacity control is achieved through a single
slide valve. The compressor is a positive displacement
type characterized by two helically grooved rotors which
are manufactured from forged steel. The 60 Hz motor
operates at 3550 RPM to direct drive the male rotor
which in turn drives the female rotor on a light film of oil.
PRODUCT DESCRIPTION
FIG. 1 – COMPONENT LOCATIONS
1 System Fans
2 System 1 Power Panel
3 System 2 Power Panel
4 Control Panel
5 Power Entry
6 System 1 Compressor
7 Cooler
8 System 2 Compressor
9 System 1 Condenser
10 Option Box
4
10
2
3
1
8
7
6 5
9
28971AR
Product Description