Engineering Manual o.. - HVAC.Amickracing

CHILLER, BOILER, AND DISTRIBUTION SYSTEM CONTROL APPLICATIONSFAN AND TOWER ISOLATIONVALVE CONTROL (TYPICAL)COMMUNICATION WITHCONDENSER PUMP/ CHILLERCONTROLLERSCOOLING TOWERSTAGING & LOADINGCONTROLLERCT4CT3CT2CT185.0M10501Multiple Centrifugal Chiller SequencingFUNCTIONAL DESCRIPTIONCHILLER4TSP445.0OFFCHILLER3TSP345.0ONCHILLER2Fig. 18. Digital control of Sequenced Cooling Towers.TSP245.0OFFCHILLER6PP4 PP3 PP2 PP151TSP145.018Y G Y G1353.8ON7TSPSETPOINT20TRPSETPOINTCONTROLCHILLERSEQUENCING21TD45.0 1445.0 19 16 45.0945.0DECOUPLERLINEPC12 200GPM10 FP1600 GPM111234FS1400 GPMTSSPLANT CONTROLCHILLERSAUTOAUTOAUTOAUTO855.0PS202PUMPSAUTOAUTOAUTOAUTOTRS15174 % SPEED% SPEEDTSSAUTOSYSTEMAUTO-MANUALSWITCH STATUSOPTIONALSECONDARYSYSTEM45.84317M10502Item No.FunctionFig. 19. Control Graphic for Multiple Similar Chillers.1,2 Secondary pump speeds.3 Icon for selection of secondary control details.4 Secondary pump leaving water temperature(operator information).5 Four chiller pump status indicators (green = on,yellow = off, red = alarm) (typical).6 Four Icons for selection of chiller detail graphic.7 Four chiller status indicators (typical), operatorinformation.8 BMCS commandable AUTO-OFF functions foreach chiller and ON-OFF-AUTO functions foreach chiller pump.9 Decoupler temperature—indicates direction of flow.10 Primary flow—indicates primary loop loading.11 Secondary flow—indicates secondary loop loading.12 Decoupler flow the difference between primaryand secondary flows.13-16 Temperatures for calculating secondary flow.17 Status of optional AUTO-MANUAL toggle switch.18 Four chiller CHWS temperature indicators.19 Operator information (from secondary system).20 Icon for selection of chilled water setpoint detailsdisplay.21 Icon for selection of chiller sequencing display(Fig. 20).ENGINEERING MANUAL OF AUTOMATIC CONTROL288