TechnicalInstructions LMVSeries
DocumentNo.LV5‐1000
Section5 Page10SCCInc.
Thepurposeofthestandardization(calibration)procedureistoestablishtherelationshipbetweenthe
LMV52analogoutputsignal(4‐20mA)andtheblowerspeed,asreadbythespeedsensorconnectedto
theLMV52.Thisisdonebyrecordingablowerspeedwith19.5mAappliedtotheVFD.Oncestarted,
basicstepsinthestandardizationareasfollows:
1. Theairdamperisopenedtopre‐purgeposition.
2. Therun/stopdry
contactintheLMV52isclosed.
3. Ananalogsignalof19.5mAisappliedtotheVFD.
4. TheVFD/blowerrampuptospeed.Afterthespeedhasstabilized,theactualpeakRPMisrecorded
byth
eLMV52.
5. Theanalogsignalisreturnedtominimum(typically4mA).
6. Therun/stopdrycontactintheLMV52isopened.
7. Theairdamperisreturnedtohomeposition.
Atypicalstandardizationprocessfora2‐pole(~3600RPM)blowerisshowngraphicallyinFigure5‐3.Ifa
standardizationwasperfo
rmedona4‐pole(~1800RPM)blower,theprocedurewouldbesimilarbutthe
blowerspeedachievedat19.5mAwouldbeapproximately1750RPM.