User guide

Example:SLEEP THRESHOLD isset to15Hz andSLEEP DELAYisset to60seconds. Ifthe drive
operates below 15Hzfor60 seconds, the drive will “go to sleep” and themotorwillstop.The drive’s
displaywillindicateSLEEP,andthedrivewill remain“sleeping”until thedrivecommandedtoaspeed
equal to greater than 17 Hz. At this point, the drive will “wake up” and ramp the motor up to the
commanded speed.
38 SLEEP BW (SLEEPBANDWIDTH)
 ThisparameterallowsthePIDfeedbacksignaltodeterminewhendriveshould“wakeup”whenoperating
inSleepMode.InprocesssystemsthatutilizeIntegralGain(seeParameter78),thedrivemaycycleinand
out of Sleep Mode more often than desired, due to the Integral function of the PID algorithm.
 WhenSLEEPBANDWIDTHisused,thefeedbacksignalmustdecreaseorincrease(dependingonwhether
thesystemisnormalorreverse-acting)bytheprogrammedamountbeforethedrivewill“wakeup”.This
parameter is set in PID units.
Example:Inanormal-actingsystem,thePIDsetpointis50PSI,SLEEPTHRESHOLDissetto20Hz,
and SLEEP BANDWIDTH is set to 5 PSI. The drive will enter Sleep Mode when the commanded speed
dropsbelow 20Hz forthe timedefined inSLEEP DELAY.The drivewill wakeup whenthe feedback
signaldropsbelow45PSI(50PSIsetpointminus5PSIbandwidth=45PSI),evenifthecommanded
speedisstillbelow20Hz.
NOTE:IfSLEEPBANDWIDTHissetto0,thisfunctionisdisabled,andthedrivewillwakeupwhenthe
commandedspeedexceedstheSLEEPTHRESHOLDplus2Hz,asdescribedinParameters36and37.
39 TB5 MIN (TERMINALTB-5INPUT)
 TB5MIN selects theoutputfrequency of the drivethatwill correspond totheminimum analog speed
referenceinput(0VDCor4mA).ThisparameterisusedinconjunctionwithParameter40-TB5MAX
todefineaspeedrangethatcorrespondstotheanalogspeedreferenceinput(0-10VDCor4-20mA).
40 TB5 MAX (TERMINALTB-5INPUT)
 TB5MAXselectstheoutputfrequencyofthedrivethat willcorrespond tothe maximumanalog speed
referenceinput(10VDCor20mA).ThisparameterisusedinconjunctionwithParameter39-TB5MIN
todefineaspeedrangethatcorrespondstotheanalogspeedreferenceinput(0-10VDCor4-20mA).
Example 1:Thedriveisrequiredtooperatefrom0to60Hzinresponsetoa0-5VDCspeedreference
signal(ratherthanthe“normal”0-10VDC).BecauseTB5MAXisbasedona0-10VDC(or4-20mA)
signal, the drive will operate at half of the TB5 MAX value if it is given a 5 VDC signal. Therefore, setting
TB5MAXto120Hzwillcausethedrivetorunat60Hzwhenitisgivena5VDCspeedreferencesignal.
NOTE: The drive can be programmed for inverse operation so that as the speed reference increases, the drive
speed will decrease, and as the speed reference decreases, the drive speed will increase. This is accomplished
bysettingTB5MINtothedesiredmaximumoutputfrequency,andTB5MAXtothedesiredminimum
outputfrequency.
Example 2: The drive is being controlled by a pressure transducer that provides a 4-20 mA signal
proportionaltoductpressure.Theminimumfrequencydesiredis20Hz,andthemaximumis60Hz.Set
TB5MIN for60 Hz,and TB5MAXfor20Hz.Astheductpressurerises,the outputsignal fromthe
transducer will increase, causing the speed of the drive to decrease. This results in a decrease in duct pressure
and a decreasing transducer signal. The drive responds to the decreasing signal by increasing speed, which
again raises the duct pressure. In this way, the average duct pressure can be maintained at a certain level. If
theaccelerationanddecelerationratesaresettoofasthowever,thedrivewillreactquicklytosignalchanges
whichwillcausethedrivespeedto“hunt”upanddownexcessively.
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