Carrier AQUAFORCE 30XA080-500 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for AQUAFORCE 30XA080: Installation instructions Controls, start-up, operation, service and troubleshooting instructions Installation instructions Product data

Contents

Carrier AQUAFORCE 30XA080-500 Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 68 page image

68Dual Chiller Sequence of Operation — With a com-mand to start the chiller, the master chiller determines whichchiller will become the lead chiller based on the configurationof Lead Lag Select, LLBL and Lead/Lag Balance Data,LLBD. The lead chiller is always started first and the lag chilleris held at zero percent capacity by the master chiller forcing thelag demand limit value to 0%. If Lead Pulldown Time (LeadPulldown Time, LPUL) has been configured, the lead chillerwill continue to operate alone for that specified time. After theLead Pulldown Time timer has elapsed and when the lead chill-er is fully loaded, either all available compression is on or at themaster demand limit value, then the lag start timer (Lag StartTimer, LLDY) is initiated. When the pulldown timer and lagstart timer has elapsed and the Combined Leaving Chilled Wa-ter Temperature is more than 3° F (1.7° C) above the set point,then the lag chiller is started. If the lag chiller’s water pumpwas not started when the machines went into occupied mode,the lag chiller water pump will be started. The lag chiller willstart with the master chiller forcing the lag chiller demand limitvalue (LAG_LIM) to the master’s demand limit value. If lead/lag capacity balance is selected, once the lag chiller has started,the master shall try to keep the difference in capacity betweenlead and lag less than 20%. The master shall then be responsi-ble for water loop capacity calculation, and will determinewhich chiller, the lead or lag, will increase or decrease capacity.When the load reduces, the lag chiller will be the first chiller tounload. To accomplish this, the lead chiller set point is de-creased by 4° F (–2.2° C) until the lag chiller unloads.PUMP OPERATION — For parallel chiller pump operation,the lead chiller’s water pump will be started. The lag chiller’swater pump will be maintained off if Lag Unit Pump Control,LAGP=0. The internal algorithm of lead chiller will control ca-pacity of the lead chiller.For series chiller operation, the pump is always controlledby the master chiller.Operating Modes — Operating modes are overridemodes that affect normal operation of the equipment. Morethan one operating mode can be in effect at the same time.Some operating modes have corresponding capacity controloverrides in the Capacity Control Overrides section onpage 47.For the Touch Pilot™ display, the status of the operatingmodes can be found in the MODES submenu, which is underthe STATUS menu. Each operating mode and its status (Yes =active, No = inactive) is listed.For the Navigator™ display, the status of the operatingmodes can be found in the MODE submenu under the OPER-ATING MODES menu. The 6 top priority operating modes aredisplayed in MD01 through MD06. To view the modes withthe Navigator display:See Table 45 for a list of operating modes.STARTUP DELAY IN EFFECT — This mode is checkedfor when the unit is started. This mode is active when the Min-utes Off Time (Unit Off to On Delay, DELY) timer is active.The unit will not start until the timer has expired. The modewill terminate when the timer expires.BASE PLATEVALVE MOTORVALVE MOTOR COVERVALVE SHAFTCLAMPING SCREWACTUATOR ARMDISENGAGEMENTBUTTONMOUNTING - FULLY CLOSEDMOUNTING - FULLY OPENFig. 39 — Typical ABV Assembly with EnclosureFig. 40 — Fully Open Ball Valvewith Actuator RemovedFig. 41 — Ball Valve Motora30-4236a30-4237a30-4238ITEM ITEM EXPANSION PATH VALUEMD01 First Active Mode Operating modesMODE 0-32MD02 Second Active Mode Operating modesMODE 0-32MD03 Third Active Mode Operating modesMODE 0-32MD04 Fourth Active Mode Operating modesMODE 0-32MD05 Fifth Active Mode Operating modesMODE 0-32MD06 Sixth Active Mode Operating modesMODE 0-32