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以下UL PAG中的对保险管炸开的现象的判定指导:( t& A1 s8 l* [# Y
5.3.8-1 Bursting fuses
+ R9 f9 p' q7 j/ @STANDARD IEC/UL 60950-1
$ L" x2 V" d7 }& y! e6 I( BAPPLICABILITY UL(C-UL) and IEC8 ?* w! ?, H! Z a6 e
(Sub)CLAUSE/ANNEX NUMBER: 5.3.8( c Y4 J. b* h( m0 x
(Sub)CLAUSE/ANNEX HEADING: Compliance Criteria for Abnormal Operating and Fault Conditions
5 `2 V! J* [' [# I8 yOTHER RELEVANT (Sub)CLAUSES/ANNEXES! G' q, {7 b. p4 j, {
(as Applicable):
9 D* t5 ^3 V. p3 L; w* u( A2.7.3, 5.3.6, 5.3.8.1, 5.3.8.2& N8 c& P. q p- C) v& W7 z6 O9 @2 @
DESCRIPTION OF ISSUE:) e2 r7 _1 W' t7 C( A7 ?4 r$ T
Type of Issue: Technical
: W+ i- n/ P+ a* v8 i" G' c+ iDuring fault testing in the Primary circuits of switch mode power supplies (SMPS) and other ITE,
1 v, U6 ?, y% _sometimes a fuse that provides supplementary (non-branch circuit) overcurrent protection and
- i' [1 |* R& e9 O% F/ ^1 ?1 J9 _! M; _that complies with either IEC 60127 or UL 248-14 will burst while clearing the circuit
% Z1 D2 ^2 R( Q [8 v/ d9 a1 SIs this an acceptable result and termination of the test?
. I) V. m& h J l" ]" b) LAPPLICATION GUIDELINE:$ H4 |: h2 E. v/ C9 Y
A fuse that bursts is not an acceptable result and termination of a test. If a fuse bursts during
+ h% l9 \$ \% Q- `6 ffault testing per sub-clause 5.3, it does not have adequate breaking (rupturing) capacity.
. Z* U' y: e. O/ G' R9 h' U* O% i2 aTherefore, such a fuse should be replaced by the manufacturer with another fuse having high0 {7 w9 W& k7 F+ l( z3 ^
breaking capacity. This consideration applies to fuses complying with both IEC 60127 and UL
6 Q" M: d& b. R7 e8 A: t0 V% L248-14.3 ^! V: a) p8 D( X% K
Placement of heat shrink or similar tubing over the fuse assembly is not a suitable solution to4 a# y* `: ~) e& I
wholly mitigate potential hazards associated with a bursting fuse. |
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