DSH 281 Open circuit of conductor of PCB during tests of clause 19

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DSH 281

Open circuit of conductor of PCB during tests of clause 19 - P: |& j( e% h; K- k

19.11.2

60335-1(ed.3) 9 _7 m  G: q4 f% ]& G, r7 K: H1 `

Standard: IEC 60335-1, Ed. 3.0 Sub clause: 19.11.2 Sheet n. 281
: ?0 s4 s7 s; \+ ?Page 1(1)
Subject: Open circuit of conductor
& u7 \2 d7 k( j  Rof PCB during tests of clause 19
Key words:
- PCB
Conductor
" M4 B8 t9 [8 g! mDecision n. 20 taken
1 j& x; f4 r8 k/ Q% ~: qAt 36th meeting/1999
+ K7 v9 C8 U3 g& L6 N9 I4 C# a" yQuestion: When conducting test of sub-clause 19.11.1 one conductor of PCB blow up
Taking into account that:
- the material of PCB withstands the burning test of sub-clause 20.1 of IEC 65,
( ^0 F3 o% J: _4 r- there are no loosened conductor which reduces creepage distances and clearances
1 k8 ^! I5 ~6 q, d) H/ Hbelow the required values
- when the test of sub-clause 19.11.2 is conducted with the open-circuited conductor
9 D+ M0 Y3 Q5 l3 n9 pbridged, an other part of the PCB blow up,
! c% ?/ o+ P  q- Z. Nare the requirements of sub-clause 19.11 fulfilled?
/ _  f. l! y: c; B1 D; |Decision: The circuit complies with the clause of the standard, if the conductor of the
+ I* J8 W( i2 Q% ?, jPCB is considered as a intentionally weak part of the circuit.
! b) `- D9 w" F1 IThis can be verified by performing the test on another sample and verify that the
- V# b! w+ ~3 Y. g4 |2 F, A7 `same conductor blow up (according § 19.1 6th paragraph), and if the conductor is
defined by the manufacturer like a specially designed weak part.

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