EDM SYSCREW AIR EVO HSE

SYSCREW 380-1260 AIR EVO HSE
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MODE 3 – ∆T CONTROL [VC]:
Thismodeprovidesvariableowsystem,consistingoftheprimarycircuit/primary+secondarycircuit.
VCmodeincludesthefollowingcomponents:
• Twopressuretransducersinstalledattheendsoftheheatexchanger(ΔP
EVAPORATOR
) factory installed.
• A dedicated system control, factory installed.
• A bypass valve with actuator supplied loose (installation by the customer).
Theoptionoffersacompleteandpredenedpackage,guaranteeingsimpleselection,supplyandcommissioning.Inpar-
ticular, the unit includes an additional control system, equipped with an evolved algorithm, which interacts with the main
control of the unit.
VCmodeprovidesfollowingadvantages:
• Anidealsolutionforsystemsworkingonxed∆T.
• Acompletevariableowsystemwithmaximumenergysavings.
• The system provides complete and reliable control of the system.
• Itreducestheoperatingcostoftheplant[OPEX].
• The pump speed will reduce automatically to save energy during low occupancy periods.
• Abypass,whichensurestheminimumowacrosstheheatexchangerthereforepreventingtheheatexchangerfrom
freezing.
TheoperatingprincipleofVCsummarizedasfollows:
• VCmodeperformsanintelligentcontroloftheowbasedontheuser-denedconstant∆T.
• Theuserdenesthe∆Tsetpointfromthechillercontroller.
• Theuserhasaexibilitytoxtherequiredoperatingheadfromthechillercontroller.
• Thepumpspeedcanreduceuntilitreachestheminimumallowableowrateontheheatexchangeroftheunit.
• Uponexceedingtheminimumallowableowthreshold,theby-passvalvewillopentriggeredbythefrequencydrive,
torecirculatetheowthatisnotrequiredbytheplant,butwhichisnecessarytoguaranteetheowrateminimum
to the exchanger.
FIGURE3:GENERALSCHEMATICSFOR∆TCONTROL