|
|
以下UL PAG中的对保险管炸开的现象的判定指导:- @- m1 y5 p: n7 @/ X' j. s
5.3.8-1 Bursting fuses
8 c5 a C4 B+ Q0 I, ^, E MSTANDARD IEC/UL 60950-1
) F0 j$ V5 G3 s$ g3 M3 rAPPLICABILITY UL(C-UL) and IEC
" I8 L* C& O) z; r(Sub)CLAUSE/ANNEX NUMBER: 5.3.8
* T, I2 c) [, c* J8 W$ ](Sub)CLAUSE/ANNEX HEADING: Compliance Criteria for Abnormal Operating and Fault Conditions
2 W7 ]2 R/ s' O. X, I" Z! X$ c3 U5 @OTHER RELEVANT (Sub)CLAUSES/ANNEXES1 G, L( ]2 G, {1 o1 C, z) H7 B
(as Applicable):7 [7 f& o3 i9 h6 K1 `: q4 R
2.7.3, 5.3.6, 5.3.8.1, 5.3.8.29 G# E. ]2 Y' r0 [0 o
DESCRIPTION OF ISSUE:
0 t0 z0 ^. r2 q. ]- pType of Issue: Technical
* W+ Q9 s& b7 s9 I% C# GDuring fault testing in the Primary circuits of switch mode power supplies (SMPS) and other ITE,
, q" B$ M2 p% q% l Qsometimes a fuse that provides supplementary (non-branch circuit) overcurrent protection and
& O) m) X- X6 [ @; V; Gthat complies with either IEC 60127 or UL 248-14 will burst while clearing the circuit
: Z: A) k9 D% f- J/ OIs this an acceptable result and termination of the test?
+ @8 V+ b$ C, _4 @- s% Q9 |4 pAPPLICATION GUIDELINE:" @( R9 F# O: f; a1 D/ ^- M
A fuse that bursts is not an acceptable result and termination of a test. If a fuse bursts during
; X1 O3 `; R' S9 T* ^' dfault testing per sub-clause 5.3, it does not have adequate breaking (rupturing) capacity.
* L- `* G- k0 b, J1 gTherefore, such a fuse should be replaced by the manufacturer with another fuse having high
s% z! g! a* E; Y, mbreaking capacity. This consideration applies to fuses complying with both IEC 60127 and UL
5 u% _9 U* n+ v) q# O9 t7 a! K9 |- L248-14.
+ T( G/ W( B4 ^: C& bPlacement of heat shrink or similar tubing over the fuse assembly is not a suitable solution to: i, u5 o1 g8 G/ {( b
wholly mitigate potential hazards associated with a bursting fuse. |
|