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Standard(s)- (year and edition):5 U9 {) K$ P; ~5 z% B8 O" s
IEC 60601-1:1988 Ed.2 Am1+Am2* [. H" }: Q7 J* Z9 ]( e/ F: D% f
Sub clause(s): 4 P" m3 |. X' PSheet n°: DSH-4123 B* X$ H6 B/ c+ E
Subject: Detection of fault + g+ V }& B! d! \$ z' t# U ~8 IKey words: SFC, detection, fault # [: |! a8 C4 v0 l1 `- ZConfirmed by CTL at its 39th meeting, in Cologne & W/ m, W9 l" t( N: D- pQuestion: ; W0 i9 C1 q1 ^1 T/ rShall a fault which remains undetected be considered a NORMAL CONDITION (NC) or a 1 _7 P/ g+ Y# pSINGLE FAULT CONDITION (SFC)? ! A& J8 v$ [$ QIf every fault is considered as SFC, regardless of whether it is detected or not, the ) A8 S) R0 Q* ?/ Q+ B6 Q! k+ w. Yconsequence will be that there is no protection required against situations where an 1 W$ V0 {- p# y0 b+ \undetected first fault is followed by a second fault which may cause a SAFETY HAZARD.! M) z8 p" L3 K: w. E8 `) m
Decision: ! d& ]" `8 G4 J+ B& j$ dIf a fault is not detected (for example by periodic inspection, maintenance, auto test, etc....), it. N; e3 X' @! h1 t A, `
shall not be considered as a SINGLE FAULT CONDITION. 7 o, ^& f( `& f5 wTime periodicity for the detection of fault depends on the risk analysis ) z* k! a% T$ f7 J: u# ?' v y: p T' M . I6 S( z0 a y, V[attach]77096[/attach]. I3 h) w9 w+ t5 t4 v
DSH 412