Carrier Aquasnap 30RW Installation, Operation And Maintenance Instructions

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Carrier Aquasnap 30RW Installation, Operation And Maintenance Instructions Manual pdf 30 page image

3011 - 30RW UNIT OPERATION WITH A DRyCOOlER11.1 - Operating principleThe 30RW units have been specially designed to optimisethe operation of systems, using drycoolers as heat rejectionsystem.With a variable-speed condenser water pump integratedinto the 30RW, the complexity of traditional systems, usinga three-way valve has been eliminated.The installation of an operational system is limited on thecondensing water loop side to connecting the drycoolerentering and leaving water piping to the 30RW unit.The Pro-Dialog Plus control of the 30RW includesalgorithms to permit constant automatic optimisation:• drycooler fan stage operation• water flow rate variation in the loop between thecondenser and the drycooler.Parallel control of the fan stages (up to 8 stages maximum)and of the variable water flow rate of the loop permityear-round system operation down to -20°C outsidetemperature without any additional control.11.2 - Auxiliary electronic analogue input and outputand discrete output board (AUX1) for control of thedrycoolerR S VCH4J7CH1 --R S V--J2--CH13CH3J4CH2 ---- G +12STATUS--TPVCH13J3CH12J124VAC--SIO J9SIOCH11--11CH10--J5TPVCH143 2 1--3 2 1CH8---- G +CH7--J6CH14CH6--J8CH5 CH9• Connector J2: Discrete outputs CH 1 to 4 for fanstages 1 to 4.• Connector J3: Discrete outputs CH 5 to 8 for fanstages 5 to 8.• Connectors J4 and J5: Analogue outputs 0-10 V dc notused on the drycoolers (only used for fan speed variationof the air-cooled condensers).• Connector J6: Analogue inputs CH 11 and 12 forambient temperature and drycooler leaving watertemperature.• Connector J9: Communication bus with NRCP masterboard of the 30RW unit.The electronic board specifically integrated in the controlbox of the drycooler and a communication bus connectedto the microprocessor board of the 30RW are used for theoverall system control.Pro-Dialog Plus optimises system operation to obtain thebest efficiency with variation of the water flow rate and thenumber of fans required for any thermal load and outsidetemperature conditions.The electronic board (AUX1) integrated in the control boxof the drycooler has analogue inputs for outside airtempe-rature and drycooler leaving water temperaturesensors, as well as eight discrete outputs permitting controlof up to eight fan stages.11.3 - Configuration of the number of fan stages andthe automatic changeover of the fan stagesPlease refer to the instructions in the Pro-Dialog Plus IOMfor the configuration of the number of fan stages to becontrolled. It is enough to enter the number of fan stagesof the drycooler in the Pro-Dialog Plus service menu. Thenumber of discrete outputs controlling the fans are activatedby the control.Pro-Dialog Plus controls the automatic changeover of allfan stages, based on the operating time and the number ofstart-ups of the different stages. This function is used toprevent that fan motors only operate a little or not at alland that their shafts seize up, especially during periodswhen the demand for cooling is low and when the outsidetemperature is low. This changeover is often specified bythe drycooler manufacturers to ensure the long operatinglife of the fan motors that are only little or not at all usedin these particular operating conditions.11.4 - Fan stage assignmentThe minimum configuration of the number of fan stages is2 for correct operation.Depending on the drycooler capacity the number of fanscan be between 2 and 8. They can be controlled by one fanor by linked pairs, if necessary.A drycooler with 4 or 6 fans installed in series for examplealong the length of the unit will result in a configuration of4 or 6 fan stages.Reciprocally a drycooler with 8 or 12 fans arranged in pairsalong the length of the unit will also result in a configurationof 4 or 6 fan stages.Configuration with 4 and 6 stages (min. 2 - max. 8)1 2 3 4 5 6AFans linked in pairs -4 and 6-stage configuration (min. 2 - max. 8)1 2 3 4 5 6A1 2 3 4 5 6legendA Entering and leaving water manifold side1 to 6 fans