TechnicalInstructions LMVSeries
DocumentNo.LV5‐1000
Section4 Page26 SCCInc.
d. Temperature/Time‐basedSteppingStartCombination
Thismethodcombinesmethodsbandcandifsetcorrectly,isthefastestwaytosafely
warm the boiler.The settings are similar to method b, but now parameter
MaxTmeModissettohaveaneffect(10minutes forexample).Whenthisisdone,the
maximum time that a step‐up in load will take is 10
minutes, regardless of the
temperature change.If the temperature change defined by StageSetp_Mod happens
beforethe10minuteselapses,thenthetemperaturechangewilltriggerthestep‐upin
load.
When this mode is used, time usually triggers the load steps at the start of boiler
warming and temperature change usually triggers the load steps closer to the
ThresholdOff temp
erature. This is due to the more rapid rise in boiler temperature at
higherfiringrates.
5. Afterparametersaresetforoneofthemethodsabove, setparameterColdStartOntoactivated.
The next time the burner is started and the water temperature is below the ThresholdOn
temperature,coldstartshouldengage.
Belowaretypicalsettingsforeachofthefourwayscoldstartcanbesetup.
Example:SteamBoilerwithanAdditi
onalTemperatureSensor
Parameter LowFireHold Temp‐based Time‐based Temp/time‐based
ColdStartOn Activated
ThresholdOn 50%(=150°F)
StageLoad 0% 5% 5% 5%
StageSetp_Mod N/A 5% 100% 10%
StageSetp_Stage StagedOperationOnly
MaxTmeMod N/A 63min 5min 10min
MaxTmeStage StagedOperationOnly
ThresholdOff 80%(=240°F)
AdditionalSens Pt1000
Temp.ColdStart ReadOnly
SetpAddSensor 300°F
ReleaseStages StagedOperationOnly
Figure4‐8:TypicalColdStartParameterSettings
Thefollowingpageshowsanexampleofatime‐basedsteppingstart.
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