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以下UL PAG中的对保险管炸开的现象的判定指导:
Y0 `% z4 B. r8 v5.3.8-1 Bursting fuses! b5 c4 l. l( M( w) S
STANDARD IEC/UL 60950-1* P' e3 R( X( V- P5 K/ L) K
APPLICABILITY UL(C-UL) and IEC3 i! n) I. c9 ^' M+ R ~
(Sub)CLAUSE/ANNEX NUMBER: 5.3.8
% e; `% p0 k; L+ z, Y, x, a(Sub)CLAUSE/ANNEX HEADING: Compliance Criteria for Abnormal Operating and Fault Conditions2 \) L0 n! Q4 q
OTHER RELEVANT (Sub)CLAUSES/ANNEXES
8 B0 V" G/ I4 j/ L3 U0 u(as Applicable):4 e V# A: M9 c: u3 @- y
2.7.3, 5.3.6, 5.3.8.1, 5.3.8.2+ V' t' `; I. w6 y. H, n
DESCRIPTION OF ISSUE:+ T2 b7 h! D: U
Type of Issue: Technical, y) R# P* ^5 |7 b
During fault testing in the Primary circuits of switch mode power supplies (SMPS) and other ITE,
+ F; A1 I. B" c8 tsometimes a fuse that provides supplementary (non-branch circuit) overcurrent protection and+ w/ ?- B, F: t2 n5 Q! [
that complies with either IEC 60127 or UL 248-14 will burst while clearing the circuit3 r2 z( |# w7 L6 e u( r7 ]. o
Is this an acceptable result and termination of the test?
8 K& Z% H8 i aAPPLICATION GUIDELINE:$ `9 j. Q# u. L" q" [% e) m [
A fuse that bursts is not an acceptable result and termination of a test. If a fuse bursts during5 y& G6 V' h/ O3 E1 [0 I4 Y
fault testing per sub-clause 5.3, it does not have adequate breaking (rupturing) capacity.
1 |8 ~3 {$ [4 X2 n: i' \$ _Therefore, such a fuse should be replaced by the manufacturer with another fuse having high
2 W; N' u1 z# w2 z% D* y! _breaking capacity. This consideration applies to fuses complying with both IEC 60127 and UL2 x d# d! F5 W7 O' J5 u& i
248-14.
7 v" x' K' a2 a* o3 DPlacement of heat shrink or similar tubing over the fuse assembly is not a suitable solution to
: E8 a" N$ O% ?% J! S8 Kwholly mitigate potential hazards associated with a bursting fuse. |
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