NuAire Labgard NU-430-400 User Manual

OM0228 Page46of99
February/2014
7.5.3 AirflowCalibration
TheNU‐430AirflowCalibrationconsistsofadjustmentstobalancetheairflowwithinthecabinetandthe
calibrationoftheairflowmonitorsensors.THISWORKSHOULDBEDONEONLYBYAQUALIFIEDTECHNICIAN
WHOCANMEASURETHEAIRFLOWFROMTHEFILTERSWITHASUITABLEVELOMETER.NuAireprovidesone
adjustmenttobalancetheairflowwithinthecabinet.Thisis:PWMsignaladjustviaDCECMmotorcontrolsystem
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Theblowerspeedcontrolsystemadjuststhecabinet'ssupplyvolumeofairflowwhilecustomersuppliedexhaust
systemcontrolstheexhaustvolumeofairflow.Sinceithasbeen NuAire'sexperiencethatthefiltersmaynot
"load"evenly,bothadjustmentsarenecessaryforpropercabinetperformance.
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Thecabinetisconsideredtobecertifiableifthefollowingairflowmeasurementsarepresent: 
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a. Downflowaverage: 60LFPM 5LFPM(.30m/
s.025m/s).
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b. Inflowaverage: 105LFPM5LFPM(.53m/
s.025m/s)usingtheDirectInflowMeasurement
 (DIM)methodoralternate3”constrictedinflowvelocitymeasurementmethod.
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Thecalibrationoftheairflowmonitorsensorsoccursduringthecabinetairflowbalancingprocedure.
Thecalibrationprocedureconsistsusingthedownflowandinflowaveragesachievedandentryofthosevalues
intothecontrolsystem.
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DCECMmotorPWMsignalDCvoltageshouldalsobemonitored andrecordeduponfinalcalibration.TheDC
voltagemaybemonitoredusinganindependentdigitalvoltmeterintheVdcmode.Thetwotestpointsto
measureDCECMmotorvoltagearelocatedontheDCmotorsignalconnectoronthemaincontrolboard.
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MOTORVOLTAGETESTPOINTS
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BEFORESTARTINGAIRFLOWCALIBRATIONPROCEDURE
LETTHECABINETRUNFORATLEAST10MINUTES.
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NuAire Labgard NU-430-400 Specifications

General

Brand	NuAire
Model	Labgard NU-430-400
Category	Air Conditioner
Language	English