UL 8750 故障测试中的8.7.2 中Exception No1对于不超过50W的电路可以豁免故障测试

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UL 8750 故障测试中的8.7.2 中Exception No1对于不超过50W的电路可以豁免故障测试。三个问题
+ L! o0 K( J! ?8 j2 Q/ j) [1.是不是说只要经过8.8 Circuit power limit measurement test的评估确定这个电路是小于50W的就可以豁免故障测试
4 l; u+ b; j* c7 R5 T# z2.这个50W的电路不论输出是高压还是低压都可以豁免吗？还是说低压输入的电路？
! U( d( G7 X1 M1 a- X, l% }5 O3.目前有一个带电池的灯具，电池输出为12V，灯具只有10W，里面有电路，这个电路需要做故障测试吗？


8.7.2 Component failure test

8.7.2.1 A unit having components such as resistors, semiconductor devices, capacitors, and the like shall
' D  b: |. V2 cnot exhibit a risk of fire or electric shock when a simulated short circuit or open circuit is imposed. In
$ ^3 I: ^' N3 o5 i* apreparation for component failure tests, the equipment, circuit diagrams, and component specifications
are examined to determine those fault conditions that might reasonably be expected to occur. Examples
! @+ v  R7 @: Oinclude: short-circuits and open circuits of semiconductor devices and capacitors, faults causing open
5 W; z- J3 F/ f( icircuits of resistors and internal faults in integrated circuits.

! X! `- A: d; H: Q9 ?
- P8 n/ U7 K1 H) W  kException No. 1: Circuits in which maximum power levels have been determined to not exceed 50 W need
& O* f1 Q# y% w/ U% N. Pnot be evaluated for component failure.

Exception No. 2: Devices supplied by a source operating within the limits for risk of fire and electric shock
need not be subject to this test.




' s! e; h4 \" g9 P6 j8.8 Circuit power limit measurement test
% j: D% x0 o0 W) W& r7 D9 Y
& @+ I7 W' j3 T3 }- J8.8.1 This test shall be used to determine if the power available to a circuit under any loading condition,
including short circuit, measured after one minute of operation exceeds a defined limit. For the purposes
3 p! d& h: O, }/ iof this test, the limit (for example, 15W or 50W) is referred to as PLIMIT. This test is applied to a circuit
(under evaluation) to determine if it has a power draw of PLIMIT or less.