Carrier AquaForce B Series Controls, Start-up, Operation, Service And Troubleshooting Instructions

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

Contents

Carrier AquaForce B Series Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 50 page image

50Operating LimitationsTEMPERATURESUnit operating temperature limits are listed in the table below.LEGEND* Lowest allowable ambient temperature for the standard unit to startand operate is 32°F (0°C). With the inclusion of wind baffles and vari-able speed fans (field fabricated and installed), the unit is capable tostart as low as 0°F (–17.8°C) and to operate as low as –20°F (–29°C)ambient temperature.† For sustained operation, EWT should not exceed 70°F (21.1°C).** Unit requires brine fluid for operation below this temperature.Low Ambient Temperature OperationIf unit operating temperatures below 32°F (0°C) are expected,the following measures are recommended:• Consider higher loop volumes, 6 to 10 gallons per nominal ton.• Loop freeze protection with glycol is strongly recommend-ed to a minimum of 15°F (8.3°C) below lowest anticipatedambient temperature.• Chilled water pump control is required.• If wind velocity is expected to be greater than 5 mph(8 km/h) wind baffles and brackets must be field fabricatedand installed. See the 30XV Installation Instructions formore information.VOLTAGEMain Power SupplyMinimum and maximum acceptable supply voltages are listedin the Installation Instructions.Unbalanced 3-Phase Supply VoltageNever operate a motor where a phase imbalance betweenphases is greater than 2%.To determine percent voltage imbalance:The maximum voltage deviation is the largest difference be-tween a voltage measurement across 2 legs and the averageacross all 3 legs.Example: Supply voltage is 240-3-60.AB = 243vBC = 236vAC = 238vCorner Grounded Delta SupplyThe Compressor and Fan VFDs used on 30XV units are automati-cally compatible with a Corner Grounded Delta Power Supply tothe system. No changes are required to be made to the VFDs.1. Determine average voltage:2. Determine maximum deviation from average voltage:(AB) 243 – 239 = 4 v(BC) 239 – 236 = 3 v(AC) 239 – 238 = 1 vMaximum deviation is 4 v.8. Determine percent voltage imbalance:This voltage imbalance is satisfactory as it is below themaximum allowable of 2%.MINIMUM FLUID LOOP VOLUMETo obtain proper temperature control, loop fluid volume must beat least 3 gallons per ton (3.25 L per kW) of chiller nominal ca-pacity for air conditioning and at least 6 gallons per ton (6.5 Lper kW) for process applications or systems that must operate atlow ambient temperatures (below 32°F [0°C]). Refer to applica-tion information in Product Data literature for details.FLOW RATE REQUIREMENTSStandard chillers should be applied with nominal flow rateswithin those listed in the Minimum and Maximum EvaporatorFlow Rates table. Higher or lower flow rates are permissible toobtain lower or higher temperature rises. Minimum flow ratesmust be exceeded to assure turbulent flow and proper heattransfer in the evaporator. See Tables 33 and 34. See Fig. 45-50for evaporator pressure drop curves.Consult application data section in the Product Data literatureand job design requirements to determine flow rate require-ments for a particular installation.TEMPERATURE F CMaximum Ambient Temperature 125 52Minimum Ambient Temperature* 32 0Maximum Evaporator EWT† 95 35Maximum Evaporator LWT 60 15Minimum Evaporator LWT 38** 3.3Maximum Evaporator Glycol EWT† 95 35Minimum Evaporator Glycol LWT 30 16.7EWT — Entering Fluid (Water) TemperatureLWT — Leaving Fluid (Water) Temperature% Voltage Imbalance = 100 x max voltage deviation from avg voltageaverage voltageAverage voltage = 243+236+2383= 7173= 239% Voltage Imbalance = 100 x 4239= 1.7%IMPORTANT: If the supply voltage phase imbalance ismore than 2%, contact the local electric utility companyimmediately. Do not operate unit until imbalance conditionis corrected.CAUTIONOperation below minimum flow rate could generate alarms,which could result in damage to the evaporator.