Carrier AquaEdge 19XRV series Operation, Maintenance And Installation Manual

Also see for AquaEdge 19XRV series: Start-up, operation and maintenance instructions Start-up and service instructions Installation instructions Start-up, operation and maintenance instructions Start-up and service instructions

Contents

53TOWER FAN HIGH SETPOINT (SETPOINT menu, default75 F [23.9 C]).The TOWER FAN RELAY HIGH is turned off when thecondenser pump is off, flow is stopped, or the EVAPORATORREFRIG TEMP is less than the EVAP REF OVERRIDE TEMPand ENTERING CONDENSER WATER is less than 70 F(21.1 C), or the difference between EVAPORATOR PRES-SURE and CONDENSER PRESSURE is less than 28 Psid(193 kPa), and ENTERING CONDENSER WATER tempera-ture is less than TOWER FAN HIGH SETPOINT minus 3 F(–16.1 C).The TOWER FAN RELAY LOW and TOWER FAN RELAYHIGH parameters are accessed from the STARTUP screen.Auto. Restart After Power Failure — ICVCSoftware Version 9 — (Applies to chillers without un-interruptable power supply installed.) The Auto. Restart featureis enabled/disabled in the SETUP3 screen. Faults that will resetwhen Auto. Restart is enabled are single cycle dropout (if en-abled); ICVC Power On Reset; line current imbalance; high linevoltage; low line voltage; Power On Reset; low DC bus voltage;high DC bus voltage; SIO comm loss with gateway; comm lossbetween gateway and DPI board. With this feature enabled,these faults are treated as alerts instead of alarms, so start-up pro-ceeds as soon as the condition is rectified. The 15-minute start-to-start and 1-minute start inhibit timers are both ignored duringthis type of start-up, and the STARTS IN 12 HOURS counter isnot incremented.The Auto. Restart feature allows the controls to make an ex-press restart. When Auto. Restart is enabled, at the time of pow-er up, if the chiller had been operating at the time of shutdown,the controls will immediately energize the CHILLED WATERPUMP output, wait 1 second, energize the CONDENSER WA-TER PUMP output, then wait 1 second to start to verify waterflow. When flow is verified, and the chilled water temperature iscalling for cooling, the guide vane is checked for closure. Be-cause the unit has VFD, the guide vanes have no closure require-ment. For units with split ring diffusers, the diffuser position isadjusted based on the GUIDE VANE / SRD FACTOR config-ured in the SETUP3 screen. The lower this factor, the moreclosed the SRD will be at restart.The oil pump is then started, and when the oil pressure is con-firmed, the controls wait 20 seconds to maintain pressure. Atthis point the compressor is commanded to start.If the Auto. Restart after Power Failure feature is enabled, thechiller has a fast restart feature for any time the chiller starts.This feature will use the same times as when the chiller starts af-ter a power failure, but will not use the modification to VFDspeed or SRD (split ring diffuser) positioning.Whenever power is restored, if power to the ICVC modulehas been off for more than 3 hours or the timeclock has been setfor the first time, the compressor starts with the slowest tempera-ture-based ramp load rate possible in order to minimize oilfoaming. The oil pump is energized occasionally during the timethe oil is being brought up to proper temperature in order toeliminate refrigerant that has migrated to the oil sump during thepower failure. The pump turns on for 30 seconds at the end ofevery 30-minute period until the chiller is started.When the VFD is started and ramping to speed, the VFD startspeed is compensated for changes due to high gas torque levels.The GAS TORQUE FACTOR in SETUP3 is used to modifystart speed. The higher the factor, the more the VFD is slowedduring restart to help prevent VFD overload.Fast Power Source Transfers — When the electri-cal system is being prepared to transfer power from generatorpower back to utility power or vice-versa, and the power trans-fer is an open transition type, and time to transfer is less than 5seconds, the chiller should be stopped before the transfer oc-curs and restarted after the transfer has been completed. If thechiller is not stopped before the transfer occurs, alarms on thechiller can occur that must be manually reset, such as a circuitbreaker trip.To accomplish shutdown and restart automatically, a set ofdry contacts should be opened 30 to 60 seconds before thetransfer occurs, then closed after the transfer is complete to re-start the chiller. The contacts must be wired to the RemoteSTART/STOP contact in the starter or VFD (see the field wir-ing diagrams) and the Remote Start contact configuration mustbe enabled.If power transfers take 5 seconds or longer, the chiller Auto.Restart after Power Failure feature (if enabled) will automati-cally restart the chiller.Water/Brine Reset — It is recommended to enable Sin-gle Cycle Dropout in the VFD configuration for this type of op-eration. Chilled water capacity control is based on achievingand maintaining a CONTROL POINT temperature, which isthe sum of the LCW SET POINT or ECW SETPOINT (from theSETPOINT screen) and a Water/Brine Reset value, if any.CONTROL POINT is limited to a minimum of 35 F (+1.7 C)for water, or 10 F (–12.2 C) for brine. Three types of chilledwater or brine reset are available and can be viewed or modi-fied on the TEMP_CTL screen, which is accessed from theEQUIPMENT SERVICE table.The ICVC default screen indicates when the chilled waterreset is active. TEMPERATURE RESET on the MAINSTATscreen indicates the amount of reset. The CONTROL POINTwill be determined by adding the TEMPERATURE RESET tothe SETPOINT.To activate a reset type, access the TEMP_CTL screen andinput all configuration information for that reset type. Then,input the reset type number (1, 2, or 3) in the SELECT/ENABLE RESET TYPE input line.RESET TYPE 1: 4 TO 20 MA (1 TO 5 VDC) TEMPERA-TURE RESET — Reset Type 1 is an “automatic” reset utiliz-ing a 4 to 20 mA or 1 to 5 vdc analog input signal providedfrom any external sensor, controller, or other device which isappropriately configured. Reset Type 1 permits up to ±30 F(±16.7 C) of reset to the chilled water set point. Inputs arewired to terminals J5-3 (–) and J5-4 (+) on the CCM (for 4-20mA input). In order to utilize a 1 to 5 vdc input, a 250-ohmresistor must be wired in series with the + input lead (J5-4).For either input type, SW2 DIP switches should be set in theON (up) position. Inputs equivalent to less than 4 mA result inno reset, and inputs exceeding 20 mA are treated as 20 mA.IMPORTANT: A field-supplied water temperature controlsystem for condenser water should be installed. The systemshould maintain the leaving condenser water temperature ata temperature that is at least 20 F (11 C) above the leavingchilled water temperature. While the tower fan relay outputsdescribed above are not a substitute for a complete con-denser water control system, they can serve as useful inputsto such a system.