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Standard: IEC 61558-1/1997 2 `% g9 g/ z; l% d6 e/ YA1/1998& |1 E4 Z8 W+ ~; J) M/ C$ u& u5 U
Sub clause: 3.1.9.1 * ~4 k, l" e. K" a) A8 E; f- p3.1.11 6 D: i, b5 P0 w9 ?15.3 – 15.5 – 27.3 : B" V2 o1 W* k; H8 E) H$ dSheet N°: 589/06& p4 O c# T" k9 [1 s2 \6 ^7 D
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Subject: Heat and fire protection ; H4 {% [: S) s5 |3 Z, p8 aKey words: 5 n1 ^1 V1 K" k3 }- Non-inherently short6 A% U3 W+ h& J* M3 N) D
circuit ' f, g j, {: X8 H: z6 g( n- Proof transformer; \& T2 c; W8 L9 _- m' z
- Fail-safe transform. # \0 [. p1 S( O( s, i6 fMeeting: , T) X1 p5 y' S4 \4 A3 j, D( dDecision confirmed1 G. ~! ^ b3 r
at 44th CTL meeting % p/ _& K% W4 r0 b+ x+ U) aQuestion: Can a small built-in transformer with integrated thermal cut-out (not/ O- m2 }& R3 B
replaceable) be considered as non-inherently short circuit proof transformer 2 A- q! m" ]3 o/ l' H8 ?( j(3.1.9.1) and as fail-safe transformer (3.1.11)? If so, can the overload test be ) H, w' n* q" `1 ?0 _5 o* D& g- Rdone according to 15.3 and 15.5? Both tests are to be performed on separate , N9 _( Z6 q. F+ s" p) tmodels. 5 T$ @8 G4 U( Z8 [' w1 b" fDecision: Yes, such transformers can be considered as fail-safe transformers if a thermal ) m4 B' |4 w4 e& j5 }& ylink is used in the input circuit. It doesn’t matter whether the input circuit is 4 o/ t8 x4 c) a0 D3 S9 Yinterrupted by the transformer itself or by a built-in thermal link that is not H: [' T! d U' {: a+ |2 u
replaceable.2 s# u* I" c* u
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[attach]77265[/attach] # H$ Y) V) u+ d7 T # i; t' \$ H! ^% ~7 w& e4 B3 E, E+ U. N6 [9 k7 ~# x' ^
DSH 589/06