Azbil DCP31 - Page 126

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Chapter 7. PARAMETER SETUP
•Position-proportionalcontroldeadzone
On2Goutputmodels,adeadzonebetweenthemotoropenandmo-
torclosedpositionsisset.
Asageneralguideline,theminimumvalueisthevaluewherethis
deadzonechangestostopmotorhuntingonceafixedvaluesetto
manualoutputisbeingoutput.
Ifthisvalueissetwithoutanymargin,themotorwillbeoperating
atalltimes,whichwillconsiderablyshortenitsservicelife.
Thefactorysettingis5%.Usethisasaguideline,andtakethecon-
trolresultsandmotorservicelifeintoconsiderationwhensetting
thedeadzone.
•Heat-coolcontroldeadzone
-100to+50%
Heat-coolcontroliscalculatedasfollows:
MFB (%)
*
Dead zone
Open-side
relay ON
Closed-side
relay ON
Control output (%)
*: Dead zone setting value
*
PV
SP
Heat-side
output
Cool-side
output
MV
(PID operation result)
Dead zone
Heat-cool output calculation
PID set selection
(1 of 4 sets)
Heat-side PID set
Constants OL, OH
Constants P, I, D, Re
PID operation
(xed to reverse action)
Cool-side
PID set
Heat-side
PID set
Cool-side PID set
Constants OL, OH
Note 2)
Note 4)
Note 3)
Note 1)