LV generator protection - engineering site - Schneider Electric

undervoltage setting:setting range setting step accuracyactivation 100 à 690 V 5 V 0 % to 5 %thresholdactivation 0.2 to 5 s 0.1 s 0 % to 20 %time delayde-activation 690 V of activation 5 V 0 % to 5 %thresholdthresholdde-activation 0.2 to 36 s 0.1 s 0 % to 20 %time delayb overvoltage setting:setting range setting step accuracyactivation 100 à 1200 V 5 V -5 % to 0 %thresholdactivation 0.2 to 5 s 0.1 s 0 % to 20 %time delayde-activation 100 V of activation 5 V -5 % to 0 %thresholdthresholdde-activation 0.2 to 36 s 0.1 s 0 % to 20 %time delay4.2.2.5 Reverse active powerb applicationreverse power protection is used to protect generators connected with the mains(as an auxiliary or standby source) and generators operating in parallelautonomously (e.g. marine).NoteFor protection of generators driven by diesel sets, the threshold must be setbetween 5 and 20 % of generator active power for a period of 2 seconds.For protection of generators driven by steam turbines, the threshold must be setbetween 1 and 5 % of active power for a period of 2 secondsb principle:the function is activated when the active power flowing in the opposite flowdirection to the energy defined by the user, is greater than the activationthreshold for a time longer than the time delay.E88012EActivation zoneDe-activationzoneDe-activation time delayActivation time delayActivationthresholdDe-activationthresholdReverse powerFigure 29.35