JOHNSON CONTROLS
15
Form 201.28-NM1.1
Issue date: 08/06/2021
2
Section 2 - Product description
YORK YVAA chillers are designed for water or 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 evaporator to ensure that each refrigerant
circuit operates correctly.
The unit structure is manufactured from heavy gauge,
galvanized steel. Many external structural parts are
coated with baked-on enamel powder “Champagne”
paint color ((RAL 7006), (Munsel No. 9.8YR4.36/1.2)).
All exposed power wiring is routed through liwquid-
tight, non-metallic conduit.
General system description
The YVAA Chiller combines the best of modern screw
compressor design with the latest technology in vari-
able speed drives. The result is superior control and
efficiency in real world conditions. The VSD enables
slowing the speed of the compressor to match the load
on the system resulting in precise chilled liquid con-
trol, minimized sound, maximum energy efficiency,
and reduced cost of ownership. The VSD also provides
soft starts with no electrical inrush. The lack of heat
build-up on start also enables required off time be-
tween starts to be reduced to a period of two minutes.
The YVAA Air-Cooled Screw Chiller utilizes many
components, which are the same or nearly the same as
a standard screw chiller of a similar size. This includes
modular frame rails, condenser, fans, compressors, and
evaporator.
The chiller consists of two screw compressors in a
corresponding number of separate refrigerant circuits,
a hybrid falling film evaporator, an air-cooled condens-
er, receiver/flash tanks, feed valves, oil separators, and
compressor mufflers.
Figure 1 -
YVAA air-cooled screw liquid chiller with variable speed drive
LD15045