York YK Manual page 100

FORM 160.75-EG1 (519)
Guide Specifications (Cont'd)
Or
In cooling mode, 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 NPLV of _____. The cooler shall be se-
lected for ______ fouling factor and a maximum liquid pressure drop of _____ kPa. The
waterside shall be designed for ____ barg working pressure. The condenser shall be
selected for _____ fouling factor and maximum liquid pressure drop of _____ kPa. Tower
condenser bundle waterside shall be designed for ___ barg working pressure.
In heating mode, each unit shall produce a capacity of ___ tons, cooling ____ l/s of ______
from _____ to _____ °C while providing heating through the heat recovery bundle of ____
l/s of ______ from _____ °C to _____ °C . Power input shall not exceed ____ kW. The
heat recovery bundle shall be selected for ______ fouling factor and maximum liquid pres-
sure drop of ____ kPa. The heating condenser bundle water side shall be designed for
____ barg working pressure.
Power shall be supplied to the compressor motor at ___ volts – __ phase - __ Hertz and
controls at ____ volts – __ - phase - __ Hertz.
Performance shall be certified or rated in accordance with the latest edition of AHRI Stan-
dard 550/590 as applicable. Only chillers that are listed in the AHRI Certification Program
for Water Chilling Packages Using the Vapor Compression Cycle are acceptable.
Each unit shall be completely factory packaged including evaporator, condenser, sub
cooler, compressor, open motor, lubrication system, OptiView™ Control Center, Variable
Speed Drive or Solid-State Starter, and all interconnecting unit piping and wiring. The
chiller shall be painted prior to shipment.
The initial charge of oil and refrigerant shall be supplied factory charged in the chiller or
shipped in containers and cylinders for field installation.
COMPRESSOR
The compressor shall be a single stage centrifugal type powered by an open drive electric
motor. The housing shall be fully accessible with vertical circular joints, with the com-
plete operating assembly removable from the compressor and scroll housing. Compres-
sor castings shall be designed for a minimum 235 psig (16.2 barg) working pressure and
hydrostatically pressure tested at a minimum of 352 psig (24.3 barg). The rotor assembly
shall consist of a heat treated steel alloy drive shaft and impeller shaft with cast aluminum,
fully shrouded impeller. The impeller shall be designed for balanced thrust, dynamically
balanced and overspeed tested for smooth, vibration free operation. Insert type journal
and thrust bearings shall be fabricated of aluminum alloy, precision bored and axially
grooved.
Internal single helical gears with crowned teeth shall be designed so that more than one
tooth is in contact at all times to provide even load distribution and quiet operation. Each
gear shall be individually mounted in its own journal and thrust bearings to isolate it from
impeller and motor forces. Shaft seal shall be provided as a double bellows, double-seal,
cartridge type. A gravity-fed oil reservoir shall be built into the top of the compressor to
provide lubrication during coastdown in the event of a power failure.
(Fixed Speed Drive) Capacity control shall be achieved by use of pre-rotation vanes to
provide fully modulating control from full load to minimum load. (Variable Speed Drive)
Capacity control shall be accomplished by the Adaptive Capacity Control (ACC), providing
100 JOHNSON CONTROLS