Carrier 19PV550 Installation, Operation And Maintenance Instructions

Also see for 19PV550: Control manual

Carrier 19PV550 Installation, Operation And Maintenance Instructions Manual pdf 25 page image

2510 - UNIT OPERATION WITH OPTION 31310.1 - Operating principleThe units have been designed to optimize the operation ofsystems, using drycoolers as free cooling system (method usinglow outdoor air temperature to chill the water of the air conditioningsystem).This system allows substantial energy and cost savings, which isthe most effective when the outdoor air temperature is low.The Touch'Pilot control of the unit includes algorithms to permitconstant automatic optimization of:- drycooler fans operation- water flow rate variation in the loop- cooling capacity (drycooler and chiller can operateindependently or simultaneously)- valves positions depending on operating mode.The control defines the optimal configuration considering waterset point value, outdoor air temperature and water loop temperature(the control will give priority to the drycooler).Parallel control of the fans and of the variable water flow rate ofthe loop permit system operation down to -20 °C outsidetemperature without any additional control.Pay attention that drycooler and chiller have to be bothequipped with the option 313Chiller NONCDC free coolingLEN communicationOATV2V control213For an optimal free cooling operation, the chiller has to beconfigurated:- on entering water temperature control- on delta temperature control in case of variable speed pump10.2 - Communication to control the drycoolerWhen the option is selected, a specific electronic board isintegrated in the control box of the drycooler. A communicationLEN bus connected between the drycooler (board AUX1) and thechiller is needed for the overall system control.This cable should be a 3 points Wago type (5 mm spacing orequivalent) and should be shielded.The board integrated in the control box of the drycooler has analoginputs for outside air temperature (mark 1), return water looptemperature (mark 3) and drycooler leaving water temperaturesensors (mark 2), as well as digital outputs permitting the controlof the fans.The option works as a system split in two parts:The chiller (with option 313)- Dedicated control algorithms with LEN connector tocommunicate and control the drycoolerThe drycooler (with option 313) :- AUX board with the I/O- OAT sensor to be place in outdoor zone.- Dry Cooler Leaving Water Temperature (factory mounted)- Water loop Temperature (to be mounted on the common pipebefore valve)- Control & 230V power supply for 2 two ways valve or onethree ways valveThe temperature difference between dry-cooler OAT and waterloop sensor defines if free cooling mode can be activated.10.3 - Configuration of the fans controlTo set the configuration corresponding the drycooler installed (numberof fans, control type – fixed or variable speed), please refer to theinstructions in the Touch'Pilot control IOM. Following theseparameters, the Touch'Pilot will activate the adequate number ofdigital outputs to control the fans.Touch'Pilot controls the automatic switching of all fans, based onoperating time and number of start-up, to ensure a long operatinglife of fan motors.Compatible fans configuration:- 1 to 20 fans- fixed speed or variable speed- fans in one l or 2 linesRefer to the drycooler electrical diagram to see the fan stagesarrangement.10.4 - Water valvesThe free cooling system requires 2 two-way valves (one NormallyOpened, one Normally Closed) or a three-way valve, not suppliedwith the unit or the dry cooler.A two-way valves kit is available in the list of drycooler accessories.The drycooler electrical box includes 230V power supply for 2two-way valves.Recommended motor valve (per default): 230V 3 pointsRefer to drycooler electrical diagram for valves wiring on customerconnections.10.5 - System installations recommandationFor physical characteristics, dimensions, performances: refer tothe drycooler documentation.For electrical connections information, refer to the electrical wiringdelivered with the drycooler.For software configuration information, refer to the controldocumentation of the chiller.For a proper drycooler installation, follow the professionalguidelines for the following topics:- Water pipe sizing- Pressure drops (verify that the available pressure of the unitpump is sufficient compared to the piping and valves pressuredrops - check for all running modes)- Maximum drycooler elevation (in relation to the unit safetyvalve)- Good positioning for temperature sensors: outside airtemperature and water loop temperature .