Section 2 - Product Description; General System Description; Figure 1 - Yvaa Air-Cooled Screw Liquid Chiller With Variable Speed Drive - York YVAA Installation Operation & Maintenance

Form 201.47-ICOM1
Issue date: 17/11/2022
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.
Before 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 liquid-
tight, non-metallic conduit.

Figure 1 - YVAA air-cooled screw liquid chiller with variable speed drive

JOHNSON CONTROLS

Section 2 - Product description

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 pro-
vides soft starts with no electrical inrush. The lack of
heat build-up on start also enables required off time
between starts to be reduced to a period of 2 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 series counter flow type hybrid falling film evapo-
rator, an air-cooled condenser, brazed plate heat ex-
changer economizer, feed valves, oil separators, and
compressor mufflers.
LD15045
2
15