LV generator protection - engineering site - Schneider Electric

Summary5.3. Summaryfunctions production set replacement safety set parallel- commentssetconnected sets*generator overload protectionoverloads b b v b v (1) (1) for Production GS allow for:- one hour overload- one hour overload every 12 hoursNote: disabling of thermal memory may be requestedshort-circuits b b v b v Magnetic setting at 1.5 lninsulation fault protectionfire ground protection b b v b v Use in case of TN-S grounding systemground fault protection v v v v For uncoupling and placing the GS out of operation if faultrestricted differentialprotection of people b b b b Protection, if necessary, of the RCD type (Zero Sequence)network monitoringcurrent unbalance v v v (2) v (2) Safety GS: the Generator Set must operate whatevercurrent unbalanceProduction and/or Replacement GS: same problem as withsupply by transformersovercurrent v (3) v (3) v v (3) (3) to be used to perform load sheddingvoltage unbalance v v v vovervoltage and b (4) b (4) v b v (4) (4) use Protection only if risk of breaking equipment /or lossundervoltage of safety is greater in the event of overvoltage /frequency b (4) b (4) v b v (4) undervoltage than in the event of breakingreverse active power ns ns ns v If the GS operates as a motor, there is a risk of:- deterioration of the diesel set- placing all sources out of operation (by overload)harmonic measurement v v v In particular, if non-linear loads are great during operationon GS (>50 %)For example Replacement GS with high power UPS(computer centre)b Important or compulsoryv Recommendedns Not significant* In case of two choices, choose that for the parallel-connected generator set category.42