KMC Controls CSC-3000 Series - REVERSE Reset Minimum and Maximum

CSC-3000 Series Pneumatic VAV Reset Volume Controllers 5 Applications Guide, Rev G
REVERSE Reset Minimum and Maximum
NOTE: Thereverseresetillustrationaboveassumes
norelaysareconnectedbetweenthe
thermostatand“T”port.
ForReverseReset(RAthermostatforcoolingorDA
thermostatforheating),performthefollowingsteps:
1a.OntheCSC-3000,disconnectthe“T”portand
leaveitopen.Temporarilyplugthetubing(but
doNOTplugtheport).
1b.Alternately,insteadofremovingthetubingfromthe
Tport,(temporarily)removetheplugfromtheCSC-
3000’s“G”port.
2. AdjusttheLOSTAT∆P(centerdial)one
adjustmentatatimeuntilthedesiredMaximum
airowisreadattheMagnehelicgaugeandis
stable.
3a.Reconnectthethermostattubingtothe“T”port.
3b.OrreinstalltheplugontheCSC-3000’s“G”port.
(SeeStep1b.)
4. Adjustthermostattocallforfullairow(15psior
moreat“T”port).
5. AdjusttheHISTAT∆P(dialonright)one
adjustment(1/4to1/2knobrotation)atatime
untilthedesiredMaximum airowisreadatthe
Magnehelicgaugeandisstable.
NOTE: Formoreaccuracy,temporarilyrelieve
thepressurebeforeeachdialadjustment.
TemporarilypullotheplugfromtheG
port(relievingthethermostatairpressure),
maketheestimatedamountofdial
adjustment,reinstalltheplug,andwait
forthedamperpositiontostabilizebefore
checkingtheow.
6. RepeatSteps1through5toverifytheseingsto
becorrectandnetuneifnecessary.
NOTE: Adjustthedialnomorethanabouta
halfrotationatatime.Aermakingany
adjustment,waitapproximatelytenseconds
whilewatchingformotioninthedamper
sha.Ifnomotionoccurs,makethenext
adjustment.
3a.Reconnectthethermostattubingtothe“T”port.
3b.OrreinstalltheplugontheCSC-3000’s“G”port.
(SeeStep1b.)
4. Adjustthethermostattocallforminimum
airow(15psiormoreat“T”port).
5. AdjusttheHISTAT∆P(dialontheright)one
adjustment(1/4to1/2knobrotation)atatime
untilthedesiredMinimum airowisreadatthe
Magnehelicgaugeandisstable.
NOTE: Formoreaccuracy,temporarilyrelieve
thepressurebeforeeachdialadjustment.
PullotheplugontheGport(relieving
thethermostatairpressure),makethe
estimatedamountofdialadjustment,
reinstalltheplug,andwaitforthedamper
positiontostabilizebeforecheckingthe
ow.
NOTE: IF the HI STAT ∆P Limit must be set at
“0” (zero minimum),
donotturntheHI
STAT∆Pknobfullyclockwise.Theknob
willadjustpastwhereazerominimumis
reached.TurningtheHISTAT∆Pknobfully
clockwisewillresultinanegativereset
condition.Thismeansthatthecontroller
willgettozerobeforegoingthroughthe
wholeresetspan.Ifazerominimumis
required,adjusttheHISTAT∆Pknob
untilthecontrollerjustbeginstocrackthe
damperopen,thenbackoslightlyand
verifyzeroairow.
6. RepeatSteps1through5toverifytheseingsto
becorrectandnetuneifnecessary.
Thermostat Pressure
Max. Airflow
Min. Airflow
Reset Start Point
• 3 psig: CSC-3021/3026
• 8 psig: CSC-3011/3016/3017/3025
• 10 psig: CSC-3023
Reset Span (5 psig)
(Cooling w/ RA Thermstat or
Heating w/ DA Thermostat)