Siemens LMV50 Series Manual

Also see for LMV50 series: Manual Operating instruction

66/327Building Technologies Basic Documentation LMV5... CC1P7550en4 Burner control 22.05.20184.2.3.6 PrepurgingThe prepurge position is approached in phase Traveling to prepurging (24).The prepurge time is determined via the following parameters:Parameter PrepurgeTmeGasPrepurgeTmeOilThese 2 parameters determine the minimum prepurge time, provided the followingparameters do not become effective.This means that the prepurge time is allocated to phases 30 through 34:In phase 30, the time defined in PrepurgePt1... is observed, followed by phase 32 orvalve proving. Then, the time of PrepurgeTmeGas possibly remaining, orPrepurgeTmeOil in phase 34, is observed, but always PrepurgePt3... as a minimum.These parameters determine the prepurge time after the following events:• Alterable lockout position• Off time >24 hours (standby)• Power failure (Power-on)• Shutdown due to interruption of gas supply (safety shutdown)Parameter PrepurgeSafeGasPrepurgeSafeOilIf these times are used, they are equally assigned to phases 30 and 34.These are minimum times that are always observed in phases 30 (prepurge time 1) and34 (prepurge time 3)!These parameters determine the minimum times for prepurging part 1 and part 3.Parameter PrepurgePt1GasPrepurgePt1OilPrepurgePt3GasPrepurgePt3OilExample:If the sum of prepurge time part 1 and part 3 exceeds PrepurgeTmeXX orPrepurgeSafeXX, this longer prepurge time applies!When using valve proving and 2 class «A» fuel valves, prepurging will not be required(as per EN 676).Skipping prepurging can be activated through parameterization.In spite of an activated parameter, prepurging is performed under the followingconditions:• Alterable lockout position• Off time >24 h (standby)• Power failure (Power-on)• Shutdown due to interruption of gas supply (safety shutdown)• Direct startParameter SkipPrepurgeGas (deactivated / activated)SkipPrepurgeOil (deactivated / activated)Caution!Deactivating valve proving does not automatically deactivate skippingprepurging. Hence, the person making the settings must ensure thatSkipPrepurgeGas is activated only if permitted for the relevant type of plant.Prepurge time aftersafety shutdownPrepurge times 1 and3Start without prepurging