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Question
' B6 l9 m ^9 \' } U& CThe first sentence of clause 3.4.3.1 of IEC 60384-14 states: ”Capacitors of each technology, rated' Y7 H) t+ s2 o! Q/ h
voltage, class and sub-class shall be separately qualified”.2 W O0 r7 f+ ~* |; L5 z' o
If it is requested to qualify a dual-class X/Y capacitor (e.g. X1:400 V, Y2:250V), is it permissible to
g. A6 ^' j5 B- F& [. d" iperform one type test only by applying for each individual test the highest test severity?; b- j/ i0 u) U8 I2 U$ J
To qualify a dual-class X/Y capacitor, testing laboratories may have different interpretations of this
8 A2 ~( Y( S! V9 vsentence.$ G( P' {9 W+ P# H* @. C1 ?6 Q9 z* P
Interpretation a): Some testing laboratories test the same capacitor series once for X1 and once for! X& i1 e9 \# s0 b3 z% u( B
Y2 at the same time in separate type tests.) ]7 D+ M3 ~/ v& M
Interpretation b): Other testing laboratories follow the opinion that the safety of the capacitors is also1 s+ s5 [2 h# [3 I# {9 `1 M8 d- T
assured if a mixture of highest testing (peak) voltages of both sub-classes is used. This means worst
5 P/ X6 D( k3 g/ acase testing, covering both sub-classes for certification.6 v ]; z" ]1 F; C( [, C1 b
Both interpretations may possibly lead to the result of compliance or non-compliance of the capacitor,, j7 o9 V7 N+ _% [
as in a) more samples are tested and in b) a single capacitor is more stressed.
# U, B& B" O8 K: }! e( Z7 \. o+ ~From the technical point of view, it should be acceptable to perform one type test only by applying the1 @% y; |; Y: @
highest test severity for each test.! H: J4 B: m) r3 G
Decision
3 b. X$ p- p/ \# ^; T7 hWhen a range of dual-class capacitors (X/Y) is qualified, it is allowed to perform one type test only, if
% Z* ]7 k3 Q4 X0 M/ g3 W+ _3 B4 Sthe highest severity of the X or Y class is applied in each respective test.7 b' Y0 {6 J9 |/ O
7 B) a" C& r4 b0 W. D! r* O) D# q+ y9 n
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