|
|
以下UL PAG中的对保险管炸开的现象的判定指导:
4 @5 S& w, ]$ |9 d5.3.8-1 Bursting fuses
5 }- `; w% c+ N" NSTANDARD IEC/UL 60950-1) E3 I3 E0 a* l
APPLICABILITY UL(C-UL) and IEC
% v: Z) {) z6 ?$ D/ L* ?/ s(Sub)CLAUSE/ANNEX NUMBER: 5.3.8( E6 }7 d) H! ~9 A+ c9 D* W
(Sub)CLAUSE/ANNEX HEADING: Compliance Criteria for Abnormal Operating and Fault Conditions
* A o- x8 K* Y% \2 oOTHER RELEVANT (Sub)CLAUSES/ANNEXES+ M8 F$ l8 C- I& P6 O
(as Applicable):
5 v9 z7 ]: \- A: r2.7.3, 5.3.6, 5.3.8.1, 5.3.8.2* _ M, I! ]% d
DESCRIPTION OF ISSUE:6 l1 ]8 X$ p3 ~/ E: w3 }2 M. ^
Type of Issue: Technical p8 v7 J+ V9 [/ ?8 V
During fault testing in the Primary circuits of switch mode power supplies (SMPS) and other ITE,
# P4 l" G7 g4 C ysometimes a fuse that provides supplementary (non-branch circuit) overcurrent protection and1 l G H1 a+ D$ c# }! j
that complies with either IEC 60127 or UL 248-14 will burst while clearing the circuit
0 {. q* `3 j( A3 h. VIs this an acceptable result and termination of the test?' }- }' G+ |" K7 j8 V
APPLICATION GUIDELINE:% M8 b( k% H4 H3 v9 Z" Q$ ^3 O
A fuse that bursts is not an acceptable result and termination of a test. If a fuse bursts during
; ]6 [5 N! Z3 a2 Ufault testing per sub-clause 5.3, it does not have adequate breaking (rupturing) capacity.
0 i9 {7 T2 w5 p' V& V" _Therefore, such a fuse should be replaced by the manufacturer with another fuse having high. W' D9 v! k+ S* B' Q9 T
breaking capacity. This consideration applies to fuses complying with both IEC 60127 and UL
6 a* |, r; {5 t2 f3 Z* t248-14.
; u/ I; R9 N2 ?& WPlacement of heat shrink or similar tubing over the fuse assembly is not a suitable solution to
' c* |' b7 j+ H/ r& V2 `2 V+ Ywholly mitigate potential hazards associated with a bursting fuse. |
|