Carrier Complete Guide to Chiller Surge and VFD Surge Protection in 19XR and 19XRV Models
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Capacity Overrides. Both of these corrective actions try to reduce the lift experienced by the compressor and help prevent a surge condition.

Surge Prevention Algorithm with VFD — This is an operator configurable feature that can determine if lift con- ditions are too high for the compressor and then take corrective action. Lift is defined as the difference between the pressure at the impeller eye and at the impeller discharge. The maximum lift a particular impeller wheel can perform varies with the gas flow through the impeller and the diameter of the impeller.

A surge condition occurs when the lift becomes so high the gas flow across the impeller reverses. This condition can even- tually cause chiller damage. When enabled, the Surge Preven- tion Algorithm will adjust either the inlet guide vane (IGV) position or compressor speed to maintain the compressor at a safe distance from surge while maintaining machine efficiency. If the surge condition degrades then the algorithm will move aggressively away from surge. This condition can be identified when the SURGE/HGBP ACTIVE? on the HEAT_EX display screen displays a YES.

The surge prevention algorithm first determines if correc- tive action is necessary. The algorithm checks two sets of operator-configured data points, the lower surge point (MIN. LOAD POINT [T1,P1]) and the upper surge point (FULL LOAD POINT [T2,P2]). The surge characteristics vary be- tween different chiller configurations and operating conditions. The surge characteristics are factory set based on the original selection with the values displayed inside the control panel of the chiller. Since operating conditions may affect the surge pre- vention algorithm, some field adjustments may be necessary.

The surge prevention algorithm function and settings are graphically displayed on Fig. 21 and 22. The two sets of load points on the graph (default settings are shown) describe a line the algorithm uses to determine the maximum lift of the com- pressor for the particular maximum operating speed. When the actual differential pressure between the cooler and condenser and the temperature difference between the entering and leav- ing chilled water are above the line on the graph (as defined by the minimum and full load points), the algorithm operates in Surge Prevention mode. This is determined when the ACTIVE DELTA T is less than SURGE/HGBP DELTA T minus the deadband.

When in Surge Prevention mode, with a command to in- crease capacity, the VFD speed will increase until maximum VFD speed is reached. At VFD MAXIMUM SPEED, when Ca- pacity still needs to increase, the IGV’s open. When in Surge Prevention mode, with a command to decrease capacity only the IGVs will close.

Surge Protection VFD Units — The PIC II monitors surge, which is detected as a fluctuation in compressor motor amperage. Each time the fluctuation exceeds an operator- specified limit (SURGE DELTA % AMPS), the PIC II registers a surge protection count. If more than 5 surges occur within an operator-specified time (SURGE TIME PERIOD), the PIC II initiates a surge protection shutdown of the chiller.

On VFD units, if a surge count is registered and if ACTUAL VFD SPEED is less than VFD MAXIMUM SPEED then motor speed will be increased by the configured VFD increase step. While the SURGE PROTECTION COUNTS are >0, a speed decrease will not be honored.

The surge limit can be adjusted from the OPTIONS screen (see Table 2). Scroll down to the SURGE DELTA % AMPS

parameter, and use the INCREASE or DECREASE softkey to adjust the percent of surge. The default setting is 10% amps.

The surge time period can also be adjusted from the OPTIONS screen. Scroll to the SURGE TIME PERIOD

parameter, and use the INCREASE or DECREASE softkey to adjust the amount of time. The default setting is 8 minutes.

Access the display screen (COMPRESS) to monitor the surge count (SURGE PROTECTION COUNTS).

Surge Protection (Fixed Speed Chiller) — The

PIC II monitors surge, which is a fluctuation in compressor motor amperage. Each time the fluctuation exceeds an operator-specified limit (SURGE DELTA % AMPS), the PIC II counts the surge. If more than 5 surges occur within an operator-specified time (SURGE TIME PERIOD), the PIC II initiates a surge protection shutdown of the chiller.

The surge limit can be adjusted from the OPTIONS screen. Scroll down to the SURGE DELTA % AMPS parameter, and

use the INCREASE or DECREASE softkey to adjust the percent of surge. The default setting is 10% amps.

The surge time period can also be adjusted from the OPTIONS screen. Scroll to the SURGE TIME PERIOD

parameter, and use the INCREASE or DECREASE softkey to adjust the amount of time. The default setting is 8 minutes.

Access the display screen (COMPRESS) to monitor the surge count (SURGE PROTECTION COUNTS).

HEAD PRESSURE REFERENCE OUTPUT (See Fig. 23) — The PIC II control outputs a 4 to 20 mA signal for the configurable Delta P (condenser pressure minus evaporator pressure) reference curve shown in Fig. 23. An output is avail- able on the ISM module [Terminal J8 (+), J8 (–) labeled spare]. For chillers with Benshaw Inc. solid-state starters terminal strip labeled J8 (+), J8 (–) located next to the RediStart MICRO™ input/output card is provided. The Delta P at 100% (chiller at maximum load condition default at 35 psi), DELTA P AT 0% (chiller at minimum load condition default at 25 psi) and MIN- IMUM OUTPUT points are configurable in the EQUIPMENT SERVICE-OPTIONS table. When configuring this output en- sure that minimum requirements for oil pressure and proper condenser FLASC orifice performance are maintained. The 4 to 20 mA output can be used as a reference to control a tower bypass valve, tower speed control, or condenser pump speed control.

Lead/Lag Control — The lead/lag control system auto- matically starts and stops a lag or second chiller in a 2-chiller water system. A third chiller can be added to the lead/lag sys- tem as a standby chiller to start up in case the lead or lag chiller in the system has shut down during an alarm condition and ad- ditional cooling is required. Refer to Fig. 17 and 18 for menu, table, and screen selection information.

DELTA P

 

 

AT 100%

 

 

 

MINIMUM

 

DELTA P

REFERENCE

 

OUTPUT

 

 

 

DELTA P

 

 

AT 0%

 

 

0 mA 2 mA 4 mA

20 mA

 

(0%)

(100%)

 

4 T0 20 mA OUTPUT

 

 

Fig. 23 — Head Pressure Reference Output

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Contents Start-Up, Operation, and Maintenance Instructions Safety ConsiderationsContents Contents Introduction Abbreviations and ExplanationsChiller Familiarization 19XR IdentificationTypical 19XR Components Refrigeration Cycle Motor and Lubricating OIL Cooling CycleVFD Cooling Cycle Lubrication CycleStarting Equipment Unit-Mounted Solid-State Starter OptionalControls Unit-Mounted Wye-Delta Starter OptionalDefinitions Variable Frequency Drive VFD 19XR Controls and Sensor Locations Major PIC II Components Panel Locations PIC II Component Panel LocationControl Panel CVC/ICVC Operation and Menus Fig Example of Status Screen 19XR Chiller Display Menu Structure CVC/ICVC 19XR Service Menu Structure Time and Date Example of Time Schedule Operation Screen Example of Set Point Screen Example 1 Chiller Display Default Screen CVC/ICVC Display DataExample 2 Maintstat Display Screen Description Status Units PointExample 3 Startup Display Screen Startup Description Status Units PointExample 4 Compress Display Screen Example 5 Heatex Display ScreenExample 6 Power Display Screen Example 7 Ismstat Display ScreenMenu Setpoint Select Description Status Units Point Default Example 8 CVC/ICVCPSWD Display ScreenCVC Icvc Description Status Units Point Example 9 Setpoint Display ScreenControl Algorithm Status Override Description Units Point Example 11 Override Display ScreenExample 12 Llmaint Display Screen Example 14 Wsmdefme Display Screen Example 13 Ismhist Display ScreenControl Algorithm Status Wsmdefme Description Units Point ISM Starter Config Data Ismconf Description Status Units Point DefaultExample 15 Netopt Display Screen Example 16 Ismconf Display ScreenSpare ALERT/ALARM Enable Example 18 SETUP1 Display ScreenExample 17 Options Display Screen Example 20 Leadlag Display Screen Example 19 SETUP2 Display ScreenLAG=2, STANDBY=3 Description Status Units Point Default Reset TypeExample 21 Rampdem Display Screen Example 22 Tempctl Display ScreenNormal Control mode occurs when Active Delta T Surge Prevention Mode occurs when Active Delta TMode IGV VFD PIC II System FunctionsPage Protective Safety Limits and Control Settings Page Capacity Overrides Evaporator Freeze Protection Icvc only a Page Surge Protection Fixed Speed Chiller Head Pressure Reference OutputPage Page Point Example of Attach to Network Device Screen Example of Holiday Period Screen Default CVC/ICVC screen, press the Menu START-UP/SHUTDOWNRecycle Sequence Fig Local Start-Up Local start-up or a manual start-up isEntering Condenser Water temperature plus 3 F -1.6C Job Data Required Before Initial START-UPEquipment Required 19XR Leak Test Procedures Page Page HFC-134a Pressure Temperature C HFC-134a Pressure Temperature FTemperature Pressure Inspect Wiring Perform dehydration as followsManufacturer Cable no Check StarterWhite G Software Configuration Parameter Benshaw RediStart Micro Menu Items Verify VFD Configuration and Change Parameters if Necessary Description Setting VFD Title Setting ParameterDescription Settings Press Status Press Compress Press Select Press Menu Press Status Press Compress Press SelectEstimated Minimum Load Conditions Load Surge Prevention Occurs TOO Soon Occurs TOO LateCCM Temperature Thermistors Control Test Menu Functions Charge Refrigerant into ChillerTests to be Devices Tested Performed Initial START-UP Refrigerant HFC-134a ChargeCheck Motor Rotation Dry Run to Test Start-Up SequenceCheck Oil Pressure and Compressor Stop Operating Instructions Operator DutiesTo Start the Chiller To Stop the ChillerPumpout and Refrigerant Transfer Procedures Operating the Optional Pumpout UnitDate Cooler Condenser Compressor TimeBearing FLATurn off pumpout condenser water Valve ConditionChillers with Isolation Valves General Maintenance Test After Service, Repair, or Major Leak IfWeekly Maintenance Guide Vane Actuator LinkageScheduled Maintenance Check Safety and Operating Controls MonthlyCompressor Bearing and Gear Maintenance Inspect the Heat Exchanger Tubes and Flow DevicesOrdering Replacement Chiller Parts When Optional Pumpout System ControlsTroubleshooting Guide Checking Pressure TransducersLlmaint HeatexOccdefcm Terminate Pumpdown Mode Shutdown in ProgressICE Build Ready to StartPrestart AlertAutorestart in Progress Running Temp ControlFault RUN CapacityLimited SensorProtective Failure toStart StopLoss CommunicationPotential FREEZE-UPSensor Alert LOW OIL PressureAutorestart PendingPressure Alert RecycleOption Sensor DiffuserThermistor Temperature F vs. Resistance/Voltage Drop DropThermistor Temperature C vs. Resistance/Voltage Drop Temperature PIC ResistancePower is connected to Plug J1 on each module Control ModulesIntegrated Starter Module Fig Chiller Control Module CCM FigReplacing Defective Processor Modules Integratedstartermodule Measure SCR Pairs Recorded Being Between CheckedHeat Exchanger Data English Number of Tubes English CodeHeat Exchanger Data SI Number of Tubes CodeCompressor Weights 19XR Additional Data for Marine Waterboxes19XR Motor Weights Standard and High Efficiency Motors English Motor19XR Waterbox Cover Weights English lb 19XR Waterbox Cover Weights SI kg Optional Pumpout System Electrical Data Additional Miscellaneous WeightsMotor Voltage Code Compressor Assembly Torques Description TorqueView B High Speed Shaft 19XR Compressor Clearances Compressor Code100 Allen-Bradley Wye-Delta Unit-Mounted Starter101 102 ISM103 Temp104 105 106 Power Panel Wiring Schematic 107Cutler-Hammer Wye Delta Unit Mounted Starter Sizes 3-5DP 108Cutler-Hammer Wye Delta Unit Mounted Starter Size 6DP 109Ground Fault Phase Current Option Separate Metering Option111 112 AUX113 FU Fuse114 115 VFDTypical Variable Frequency Drive VFD Wiring Schematic 116117 118 119 120 121 122 Index Index Remove and use for job file JOB Data RequiredInspect Wiring and Record Electrical Data Ratings CL-240 to 100 10 to60.0 15 toCL-4 200 to 460105 to 115 85 to30 to 50 to20 to Psi CL-6150 to 90 to125 125 to90 to 100 65 toAmp 250 CL-8 25 to CL-950 to 145 CL-100000 to 02000000 to 0200 CL-11002 Power Module Dependent Selected motor 100% amps 004 To H.022 Job Sheet 60 for 60 Hz and 50 for 50 Hz028 10 to Job Sheet 60 for 60 Hz and 50 for 50 Hz 000 100 to Selected line voltageCL-13 CCN Local Reset CL-14Page Incurring obligations
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19XR, XRV specifications

The Carrier 19XR and 19XRV chillers are sophisticated cooling solutions that represent the forefront of HVAC technology. Designed for large commercial and industrial applications, these chillers provide exceptional performance, energy efficiency, and reliability, making them ideal for a variety of environments ranging from hospitals to manufacturing facilities.

One of the most significant features of the Carrier 19XR and 19XRV chillers is their advanced scroll compressor technology. These units employ a tandem scroll design that enhances efficiency while minimizing operational noise. This makes them ideal for urban environments where noise restrictions may be in place. Moreover, the compressors are equipped with variable speed drive options in the 19XRV model, which allows for greater energy savings by adjusting cooling output based on real-time demand.

In addition to their advanced compressors, the 19XR and 19XRV units incorporate the Carrier GreenChoice refrigerant, which has a lower global warming potential compared to traditional refrigerants. This innovative choice not only meets regulatory requirements but also contributes to sustainability goals, making these chillers a responsible choice for environmentally conscious organizations.

The units are engineered with a robust heat exchanger design, which enhances heat transfer efficiency and overall system performance. This ensures optimal operation even in extreme conditions. They feature a microprocessor-based control system that allows for precise monitoring and control of the chiller’s performance, enabling operators to make real-time adjustments to maximize energy efficiency.

The Carrier 19XR and 19XRV chillers also prioritize serviceability. The design incorporates easy access to key components, simplifying maintenance procedures and reducing downtime. This focus on maintainability extends the lifespan of the equipment, leading to lower lifecycle costs.

In terms of connectivity, these chillers are equipped with advanced Building Management System (BMS) integration capabilities. This allows for seamless monitoring and control of the chillers using a centralized platform, facilitating energy management and operational optimization.

Overall, the Carrier 19XR and 19XRV chillers stand out in the market for their blend of cutting-edge technology, energy efficiency, and user-friendly features. They are engineered to meet the demanding needs of modern commercial and industrial applications, making them a preferred choice for facility managers seeking reliable cooling solutions.
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