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| DSH 418
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| Load resistance in relation to load current
3 k# ~* X2 g- B/ e2 h. z | 57.9, 57.9.1
( \- e! z* z! p) N3 i: g8 u P( w; j | 60601-1(ed.2);am1;am29 }+ C2 E+ k, X; [
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Standard(s)- (year and edition):
) h" i: ]' V s/ XIEC 60601-1:1988 Ed.2 Am1+Am2% j& C( E* H7 f/ B" i2 n* j
Sub clause(s): 57.9, 57.9.15 ^9 J4 x1 D$ ]! X+ J
Sheet n°: DSH-418
) _) M) b5 b7 o; M6 H1 `Subject: Load resistance in relation to load current
) j2 {; o: J# x: b4 {Key words: Load resistance, load current0 P* S: n! a* l8 ]" _' R
Confirmed by CTL at its 39th meeti ng, in Cologne
! Y- ^# i! }- _) L# [ BQuestion:
y- a4 x/ k! X) B) U/ v' {4 UPractically the test is performed with the winding under overload connected to a resistor with
( z8 e9 C7 r* Pthe resistance value that yields the correct test current in accordance with Table XX. As the G, F) A* M: o; ?4 \& N
windings get heated during the test their resistance increases and one has to decrease the& Z+ Y9 R+ x2 D+ t, L3 q/ \: W2 g
value of the load resistor to keep the current in the fused circuit in accordance with Table XX
5 d0 ^3 Q& M" ]during the test. Since the decrease of current is a result of the increase in the winding’s0 ]' K$ @% m* P0 Y ^& x
temperature, it seems to be an unrealistic fault condition to keep the current in the fused circuit4 }/ p5 s0 b! v5 q9 `. w! d
unchanged instead of keeping the load resistance unchanged.# C) X; y5 Q0 [, Y$ l
Decision:+ M- p, M/ \+ I: a
The test load current must be maintained at its original value
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