User manual YORK YS

[. . . ] FORM 160. 80-EG1 (808) Model YS Rotary Screw Liquid Chillers Design Level E Rated in Accordance with the latest edition of ARI STANDARD 550/590 100 thru 675 tons (315 thru 2375 KW) r-22 and r-134a TABLE OF CONTENTS pAGe INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OpTIVIew CONTROL CeNTeR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MeCHANICAL SpeCIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] The loss or severe reduction of water flow could seriously impair the chiller performance or even result in tube freeze up. Condenser water ­ The chiller is engineered for maximum efficiency at both design and part-load operation by taking advantage of the colder cooling tower water temperatures which naturally occur during the winter months. Appreciable power savings are realized from these reduced heads. The minimum entering condenser water temperature for other full and part load conditions is provided by the following equation: For R-22; Min ECWT = LCHWT + 11+ [(% load/100) x (15 - full load condenser water T)] For R-134a; Min ECWT = LCHWT + 16 + [(% load/100) x (10 - full load condenser water T)] where: eCwT = entering condenser water temperature LCHwT = leaving chilled water temperature MULTIPLE UNITS Selection ­ Many applications require multiple units to meet the total capacity requirements as well as to provide flexibility and some degree of protection against equipment shutdown. There are several common unit arrangements for this type of application. The Millennium Chiller has been designed to be readily adapted to the requirements of these various arrangements. Application Data - continued Parallel Arrangement (Refer to Fig. 1) ­ Chillers may be applied in multiples with chilled and condenser water circuits connected in parallel between the units. 1 represents a parallel arrangement with two chillers. parallel chiller arrangements may consist of equally or unequally sized units. when multiple units are in operation, they will load and unload at equal percentages of design full load for the chiller. Depending on the number of units and operating characteristics of the units, loading and unloading schemes should be designed to optimize the overall efficiency of the chiller plant. It is recommended to use an evaporator by-pass piping arrangement to bypass fluid around evaporator of any unit which has cycled off at reduced load conditions. It is also recommended to alternate the chiller cycling order to equalize chiller starts and run hours. 2) ­ The chillers may be applied in pairs with chilled water circuits connected in series and condenser water circuits connected in parallel. All of the chilled water flows through both evaporators with each unit handling approximately one-half of the total load. when the load decreases to a customer selected load value, one of the units will be shut down by a sequence control. Since all water is flowing through the operating unit, that unit will cool the water to the desired temperature. BRINE APPLICATIONS The YS Screw Chiller, utilizing the Frick Refrigeration compressor, is a good match for the high head requirements of low temperature brine applications. This is particularly true of thermal ice storage systems, typically requiring 22°F (­5. 6°C) to 24°F (­4. 4°C) leaving brine temperatures. This performance is enhanced with the standard thermal storage control mode described on page 6. particular attention must be paid to the application of two or more chillers with evaporators in parallel or series when the brine temperature is below 32°F (0°C). [. . . ] This data can be preprogrammed to print from 1 minute to 1 day. The capability to interface with a building automation system to provide: a. Remote leaving chiller liquid temperature adjust c. Run contacts COMPRESSOR MOTOR STARTER (OPTION, 00 - 600V) The chiller manufacturer shall furnish a reduced-voltage Solid State Starter for the compressor motor. [. . . ]