Carrier AquaEdge 19XR series Start-up, Operation And Maintenance Instructions Manual

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

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Carrier AquaEdge 19XR series Start-up, Operation And Maintenance Instructions Manual Manual pdf 56 page image

56Fast 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 to the Re-mote START/STOP contact in the starter or VFD (See the fieldwiring diagrams) and the Remote Start contact configurationmust be enabled.If power transfers take 5 seconds or longer, the chiller AutoRestart after Power Failure feature (if enabled) will automati-cally restart the chiller.Water/Brine Reset — For this application, it is recom-mended the Single Cycle Drop Out in the ISM Configurationbe enabled. Chilled water capacity control is based on achiev-ing and maintaining a CONTROL POINT temperature, whichis the sum of the LCW SET POINT or ECW SETPOINT (fromthe SETPOINT 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, in-put the reset type number (1, 2, or 3) in the SELECT/ENABLERESET TYPE input line.RESET TYPE 1: 4 to 20 mA (1 to 5 vdc) TEMPERATURERESET – Reset Type 1 is an “automatic” reset utilizing a 4 to20 mA or 1 to 5 vdc analog input signal provided from anyexternal sensor, controller, or other device which is appropri-ately configured. Reset Type 1 permits up to ±30° F (±16.7° C)of reset to the chilled water set point. Inputs are wired to termi-nals J5-3 (–) and J5-4 (+) on the CCM (for 4 to 20 mA input).In order to utilize a 1 to 5 vdc input, a 25-ohm resistor must bewired in series with the + input lead (J5-4). For either inputtype, SW2 DIP switch 2 should be set in the ON (up) position.Inputs equivalent to less than 4 mA result in no reset, andinputs exceeding 20 mA are treated as 20 mA.RESET TYPE 2: REMOTE TEMPERATURE RESET —Reset Type 2 is an automatic chilled water temperature resetbased on a remote temperature sensor input signal. Reset Type2 permits ± 30 F (± 16 C) of automatic reset to the set pointbased on a temperature sensor wired to the CCM module (seewiring diagrams or certified drawings). The temperature sensormust be wired to terminal J4-13 and J4-14. To configure ResetType 2, enter the temperature of the remote sensor at the pointwhere no temperature reset will occur (REMOTE TEMP –>NO RESET). Next, enter the temperature at which the fullamount of reset will occur (REMOTE TEMP –> FULLRESET). Then, enter the maximum amount of reset required tooperate the chiller (DEGREES RESET). Reset Type 2 can nowbe activated.RESET TYPE 3 — Reset Type 3 is an automatic chilled watertemperature reset based on cooler temperature difference.Reset Type 3 adds ± 30 F (± 16 C) based on the temperaturedifference between the entering and leaving chilled watertemperature.To configure Reset Type 3, enter the chilled water tempera-ture difference (the difference between entering and leavingchilled water) at which no temperature reset occurs (CHWDELTA T –> NO RESET). This chilled water temperature dif-ference is usually the full design load temperature difference.Next, enter the difference in chilled water temperature at whichthe full amount of reset occurs (CHW DELTA T –> FULL RE-SET). Finally, enter the amount of reset (DEGREES RESET).Reset Type 3 can now be activated.Demand Limit Control Option — The demand limitcontrol option (20 mA DEMAND LIMIT OPT) is externallycontrolled by a 4 to 20 mA or 1 to 5 vdc signal from an energymanagement system (EMS). The option is set up on theRAMP_DEM screen. When enabled, 4 mA is the 100% de-mand set point with an operator-configured minimum demandat a 20 mA set point (DEMAND LIMIT AT 20 mA).The auto. demand limit is hardwired to terminals J5-1 (–)and J5-2 (+) on the CCM. Switch setting number 3 on SW2will determine the type of input signal. With the switch set atthe ON position the input is configured for an externally pow-ered 4 to 20 mA signal. With the switch in the OFF position theinput is configured for an external 1 to 5 vdc signal. In order touse a 1 to 5 vdc input instead of 4 to 20 mA, install a 25-ohmresistor in series with the + lead at terminal J5-2.Surge Prevention — Constant Flow and Vari-able Primary Flow (VPF) — A surge condition occurswhen the lift becomes so high that the gas flow across the im-peller reverses. This condition can eventually cause chillerdamage. The surge prevention algorithm notifies the operatorthat chiller operating conditions are marginal and to take actionto help prevent chiller damage such as lowering entering con-denser water temperature.The surge prevention algorithm is an operator-configurablefeature that can determine if lift conditions are too high for thecompressor and then take corrective action. Lift is defined asthe difference between the saturated temperature at the impellereye and at the impeller discharge. The maximum lift a particu-lar impeller wheel can perform varies with the gas flow acrossthe impeller and the size of the wheel.Variable Flow Surge prevention is the current standard forboth constant and variable primary flow chilled water systems.Variable Primary Flow Surge Prevention does not require ameasurement of COOLER DELTA T and is thus unaffected bychanges in flow. With Variable Primary Flow Surge Preven-tion there is no difference in field configuration between con-stant and variable flow water systems.The controls calculate the conditions at which the compres-sor will surge based on operating conditions and configuredvalues entered into the OPTIONS screen.The configurations as used by the controls would plot outon a graph as a curved or stepped line. If the present operatingconditions plot at or above this line, surge prevention is turnedon.The way in which surge prevention functions will differwith the presence or absence of hot gas bypass and variablespeed drive.Hot Gas Bypass (Optional) Algorithm — If ahot gas bypass solenoid valve is present and the HGBP OP-TION in the OPTIONS table is set to 1 or 2, this operator con-figurable feature can determine if load conditions are too lowfor the compressor and corrective action can be taken.HGBP OPTION = 0 — The HGBP algorithm is disabled.HGBP OPTION = 1 (VFD OPTION DISABLED) — Thealgorithm determines if corrective action is necessary bychecking the chiller operating point against an operator