Guide Specifications
FORM
YORK Model YCWS ______ Packaged Chiller(s). The
(each) unit shall have a cooling capacity of ______ tons
with Compressor kW when cooling GPM of water from
______ °F (°C) to ______ °F (°C) and with ____ GPM of
condensing water entering at ____ °F (°C) and leaving
at _____ °F (°C), and a cooler fouling factor of _____
and condenser water fouling factor of _____. The water
pressure drop shall not exceed ______ feet (kPa) of
water through the cooler and ______ feet (kPa) of water
through the condenser. The unit overall dimensions shall not exceed _____feet (mm) _____ ins. in length, ______
feet (mm) _____ ins. in width and _____feet (mm) _____
in height. The unit operating weight shall not exceed
_____ lbs. (Kg).
GENERAL
The (Each) Packaged Water Cooled Screw Chiller shall be completely factory assembled (in an ISO 9001 regis- tered facility) including all interconnecting refrigerant pip- ing and internal wiring of controls, mounted on a steel base which accommodates the condenser, compressor(s) and evaporator. Operating test shall in- clude operation with water flowing through the evapora- tor.
Unit shall be painted with Caribbean Blue enamel. The unit shall be shipped with a full operating charge of R-
22.The unit shall contain two separate refrigerant cir- cuits, each with a single compressor for standby opera- tion. All units shall be designed and constructed in ac- cordance with the applicable sections of the following: American Society of Heating, Refrigeration and Air Con- ditioning Engineers ANSI/ASHRAE 15 Safety Code for Mechanical Refrigeration: American Society of Mechani- cal Engineers ASME Pressure Vessel Code; National Electrical Code/National Fire Protection Association NFPA 70. The unit shall be produced at an ISO 9001 registered facility. All chillers are rated in accordance with ARI Standard 550/590.
COMPRESSORS
Compressors shall be direct drive,
Motors shall feature refrigerant
APT2000 type magnet wire.
Lubrication shall feature external oil separators with no moving or fragile parts, 31 bar (450psig) design working pressure, and UL listing. Refrigerant system differential pressure shall provide oil flow through service replace- able, 0.5 micron, full flow, cartridge type oil filter internal to compressor. Filter bypass, less restrictive media, or oil pump not acceptable.
Compressors shall start at minimum load position. Ca- pacity control range from 100% to 10% of chiller full load using continuous function slide valves, and without hot gas bypass. Step unloading unacceptable. Provide Mi- croprocessor controlled, output pressure regulating ca- pacity control valve to command compressor capacity independent of control valve input pressure and balance compressor capacity with cooling load.
CAPACITY CONTROL SYSTEM
Continuous function, microprocessor controlled, 3- way proportional Capacity Control Valve provides regulated output pressure independent of valve input pressure for a stable, smooth, and precise match of compressor ca- pacity to cooling load to 10% of chiller capacity.
COOLER
The cooler shall be a direct expansion shell and tube type with refrigerant in the tubes and liquid to be chilled in the shell. The design working pressure of the cooler shell (liquid) side shall be 150 PSIG for the tube (refrig- erant) side. Refrigerant heads shall be removable. The cooler shall be covered with 3/4" flexible closed cell foam insulation (K = 0.25 maximum) to prevent sweating. The cooler shall be constructed and tested in accordance with ASME Code requirements. Vent and drain connec- tions shall be included. The water connections shall be fully accessible and grooved to accept victaulic couplings if used (by others).
CONDENSER
The condenser is a cleanable
REFRIGERANT CIRCUITS
Two independent refrigerant circuits will be furnished on
YORK INTERNATIONAL | 47 |
