Load resistance in relation to load current" X7 N2 R3 p+ z+ p
57.9, 57.9.1 ) A! b& ~7 V: y5 W- L
60601-1(ed.2);am1;am2 , C$ v' g% k0 ~! N
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Standard(s)- (year and edition):. B2 g* B# Q w! s& N
IEC 60601-1:1988 Ed.2 Am1+Am2% x* c; R t, `) t
Sub clause(s): 57.9, 57.9.11 q8 }1 |, r' }/ {
Sheet n°: DSH-418$ r8 W7 X# _- e% x- Y$ e
Subject: Load resistance in relation to load current $ V# R! Y/ g! l, _; w8 pKey words: Load resistance, load current 5 N; q* V) ~8 ZConfirmed by CTL at its 39th meeti ng, in Cologne2 M% w& w8 h$ \0 }4 L" ^) ~
Question: + K. K) Z9 q- _) JPractically the test is performed with the winding under overload connected to a resistor with+ |) e6 m2 p* Y0 U
the resistance value that yields the correct test current in accordance with Table XX. As the% V7 R+ S+ c3 y" d" r% [, A
windings get heated during the test their resistance increases and one has to decrease the ( @4 U3 D& Z, d% K7 K2 _2 kvalue of the load resistor to keep the current in the fused circuit in accordance with Table XX m& X/ C }+ @( h* p
during the test. Since the decrease of current is a result of the increase in the winding’s0 P: L4 s1 |+ W
temperature, it seems to be an unrealistic fault condition to keep the current in the fused circuit " @- l" N& U% N! Z9 d6 _5 }( h" j6 |unchanged instead of keeping the load resistance unchanged. ! h$ A! | _) A8 \6 T. c' e2 hDecision: ! N9 D, D9 S% aThe test load current must be maintained at its original value# L2 F, ]4 Z' N: N5 c
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DSH 418( c6 {! M9 h6 `. v M. X# V* a