York YR - Manual (Page 36)

36 YORK INTERNATIONAL
FORM 160.81-EG1
GENERAL
Furnish and install where indicated on the drawings
YORK M
AX E Rotary Screw Liquid Chilling Unit(s). Each
unit shall produce a capacity of tons, cooling
GPM of from °F to °F when supplied
with _____ GPM of condenser water at
°F. Power input shall not exceed kW with an IPLV
(NPLV) of _____. The evaporator shall be
selected for ft
2 °F hr/BTU fouling factor and a
maximum liquid pressure drop of ft. Water side
shall be designed for 150 or 300 psig working pressure.
The condenser shall be selected for fouling
factor and maximum liquid pressure drop of ____ ft.
Water side shall be designed for 150 or 300 psig work-
ing pressure. Power shall be supplied to the compres-
sor motor at volts – 3-phase – (60)(50) Hertz and
controls at 115 volts –1-phase – (60)(50) Hertz.
– (or) –
Furnish and install where indicated on the drawings
YORK M
AX E Rotary Screw Liquid Chilling Unit(s). Each
unit shall produce a capacity of kW, cooling L/S
of from °C to °C when supplied with
____ L/S of condenser water at °C. Power input
shall not exceed kW with an IPLV (NPLV) of
____. The evaporator shall be selected for M
2 °C/W
fouling factor and a maximum liquid pressure drop of
___ kPa. Water side shall be designed for 1034 or 2068
kPa working pressure. The condenser shall be selected
for M
2 °C/W fouling factor and maximum liquid
pressure drop of kPa. Water side shall be designed
for 1034 or 2068 kPa working pressure. Power shall be
supplied to the compressor motor at volts – 3-phase
– 50 Hz and controls at 115 volts – 1-phase – 50 Hz.
Performance shall be certified or rated in accordance
with the latest edition of ARI Standard 550/590-98 as
applicable. Only chillers that are listed in the ARI Certi-
fication Program for Water Chilling Packages using the
vapor compression cycle are acceptable.
Each unit shall be completely factory packaged includ-
ing evaporator, condenser, subcooler, oil separator, com-
pressor/motor, lubrication system, OptiView Control
Center, Solid State Starter (optional), refrigerant isola-
tion valves (optional) and all interconnecting piping and
wiring. The factory package shall consist of a “Leaktight”
Guide Specifications
design, with no pipe thread connections that can loosen
and leak over time. All units shall ship with a full charge
of refrigerant HFC-134a and oil. Alternatively, the chiller
shall be shipped with the compressor, control panel and
oil separator removed (Form 3) or also with the shells
separated (Form 7) to allow rigging into the equipment
room. All units that ship disassembled shall be assembled
and factory run tested prior to disassembly and shipment).
Compressor
The compressor shall be a rotary-screw type. The com-
pressor housing shall be of cast iron, precision machined
to provide minimal clearance for the rotors. The rotors
shall be manufactured from forged steel and use asym-
metric profiles operating at a maximum speed of (3570
RPM/60 Hz) (2975 RPM/50 Hz). The compressor shall
incorporate a complete anti-friction bearing design to re-
duce power and increase reliability; four separate cylin-
drical roller bearings to handle radial loads; and two 4-
point angular contact ball bearings to handle axial loads.
A check valve shall be incorporated in the compressor
housing to prevent rotor backspin during shutdown.
Capacity control shall be achieved by use of a slide
valve to provide fully modulating control from 100% to
20% of full-load. The slide valve shall be actuated by
system differential pressure, controlled by external so-
lenoid valves through the OptiView Control Center. The
unit shall be capable of operating with lower tempera-
ture cooling tower water during part-load operation in
accordance with ARI Standard 550/590.
Lubrication System
An adequate supply of oil shall be available to the com-
pressor at all times. During start-up and coastdown, this
shall be achieved by oil reservoirs in the compressor.
During operation, oil shall be delivered by positive sys-
tem pressure differential.
All chillers shall be provided with a single oil filter hous-
ing with isolation valves. An optional dual filter is avail-
able which allows immediate switching from one filter
to the other, eliminating downtime during filter changes.
The off-line oil filter must be capable of being changed
during chiller operation. The chiller shall ship with a 3
micron absolute oil filter, (two filters for dual filter op-
tion) maintaining a clean oil system and ensuring supe-
rior compressor life.