System pro M compact® - Piti Group

Systempro M compact ®Technical detailsCoordination tables: residual currentprotection selectivityRCDsAI1 I1I1I2 I2I2BDubiousselectivityCertain Certainselectivity selectivityChronometric (total) selectivityTo achieve total selectivity, delayed or selective RCDs must be installed.The tripping times of the two devices connected in series must be co-ordinated so that the totalinterruption time t2 of the downstream breaker is less than the upstream breaker’s no-response limittime t1, for any current value. In this way, the downstream breaker completes its opening before theupstream one.To completely guarantee total selectivity, the I value of the upstream device must also be more thandouble that of the downstream device in accordance with IEC 64-8/563.3, comments. The operativerule to obtain an amperometric (partial) selectivity is In of the upstream breaker = 3 x In of the downstreambreaker (e. g.: F 204, S type, 300 mA upstream; F 202, A type, 100 mA downstream).For safety reasons, the delayed tripping times of the upstream breaker must always be below thesafety curve.t [s]LegendABI1t1I2t21234x I1 Theoretical safetycurve2 RCD A tripping characteristic3 No-response limittimes4 RCD B trippingcharacteristic10Table of RCD selectivitySelection tables ............................... pag. 3/2Upstream In 10 30 100 300 300 500 500 1000 1000[mA]Downstream In inst inst inst inst S inst S inst S[mA]10 inst n n n n n n n n30 inst n n n n n n n100 inst n n n n n n300 inst n n300 S n n500 inst500 S1000 inst1000 Sinst=instantaneous S=selective n=amperometric (partial) selectivity n=chronometric (total) selectivityABB10/85