Carrier AquaForce 30XV140 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for AquaForce 30XV140: Controls, start-up, operation, service and troubleshooting instructions

Contents

47OPERATIONSequence of Operation — With a command to start thechiller, the evaporator pump will start. After verifying waterflow, the control will monitor the entering and leaving watertemperature. If the need for mechanical cooling is determined,the control decides which circuit and compressor to start. Thecontrol will start the required compressor completely unloadedand de-energize the oil separator heater (if already energized).The control will continue to load this circuit by increasing theVFD frequency to satisfy cooling requirements. Once fullyloaded, the control will start the second circuit to satisfy load asrequired. Shutdown of each circuit under normal conditions oc-curs in the opposite sequence to loading. Once a circuit is fullyunloaded the compressor is shut off and the EXV will closecompletely.ACTUATED BALL VALVE (ABV) — For chillersequipped with this option (standard in most regions), either oneor two discharge ABVs are located in the discharge line of eachcircuit of the unit. See Fig. 40 for a typical ABV assembly withenclosure. The ABV is a motorized ball valve, which is used toclose the discharge line to prevent refrigerant migrating fromcondenser to the evaporator when the circuit is off. The valvewill be opened before the compressor is started and will nor-mally close when pressure equalizes between suction and dis-charge lines.The actuated ball valves are linked to the evaporator heateroperation in the controls. Evaporator Heater option (MainMenu Configuration Menu Factory Parameters Evapo-rator Heater Installed = yes) must be enabled for the actuatedball valve to operate.See Fig. 41 for a view of a fully open ball valve with the ac-tuator removed. The flat surface at the top of the valve shaft isparallel to the discharge line. The ball valve motor mountingplate should be perpendicular to the discharge line at all times.If not, adjust it by loosening the set screw on the side of thevalve, reposition assembly and tighten set screw.See Fig. 42 for a view of the ball valve motor mountingwith a fully open valve. The motor actuator arm should be at acounterclockwise position, with the valve shaft in a parallel po-sition. If not in a parallel position, loosen the clamping screwand push the disengagement button to rotate the actuator armuntil it stops. Retighten the clamping screw.ABV Manual Operation — The ABV can be operated manu-ally as a discharge service valve by completing the followingsteps:1. Remove the actuator cover.2. With the compressor off hold down the Disengagement(Push) button. See Fig. 42.3. Close the ABV by turning the shaft adapter by hand orwith a wrench so that the flats on the end of the shaft areperpendicular to the discharge line.4. Release the Push button.5. Disconnect the control power cable to the ABV.Dual Chiller Sequence of Operation — With acommand to start the chiller, the master chiller determineswhich chiller will become the lead chiller based on the con-figuration of Lead Lag Select (lead_sel) and Lead/Lag Bal-ance Delta (ll_bal_d). The lead chiller is always started firstand the lag chiller is held at zero percent capacity by themaster chiller forcing the lag demand limit value to 0%. IfLead Pulldown Time (lead_pul) has been configured, thelead chiller will continue to operate alone for that specifiedtime. After the Lead Pulldown Time timer has elapsed andwhen the lead chiller is fully loaded, either all availablecompression is on or at the master demand limit value, thenthe lag start timer (lstr_tim) is initiated.BASE PLATEVALVE MOTORVALVE MOTOR COVERFig. 40 — Typical ABV Assembly with Enclosurea30-4236VALVE SHAFTFig. 41 — Fully Open Ball Valvewith Actuator Removeda30-4237CLAMPING SCREWACTUATOR ARMDISENGAGEMENTBUTTONMOUNTING - FULLY CLOSEDMOUNTING - FULLY OPENFig. 42 — Ball Valve Motora30-4238