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
; M$ i: [) E" ~$ \; A7 S1.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
2.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？
9 E  Q$ n( Q* M. a+ n0 r3.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？


5 m$ f$ B+ _. h' I1 n+ R8.7.2 Component failure test

8.7.2.1 A unit having components such as resistors, semiconductor devices, capacitors, and the like shall
not exhibit a risk of fire or electric shock when a simulated short circuit or open circuit is imposed. In
+ N1 V, K) W2 X. _( c5 v4 z2 d3 Fpreparation 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
% S+ M3 ^! |& \. [  t& iinclude: short-circuits and open circuits of semiconductor devices and capacitors, faults causing open
circuits of resistors and internal faults in integrated circuits.


5 |# t9 `3 x+ a9 K$ c0 |Exception No. 1: Circuits in which maximum power levels have been determined to not exceed 50 W need
' N" @: e- Z" ~9 K& x' m% Rnot be evaluated for component failure.

- i$ l1 q  a7 B, yException No. 2: Devices supplied by a source operating within the limits for risk of fire and electric shock
( |; a, x& r2 M; x. m! S0 ?need not be subject to this test.

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+ q  ?2 @, C" s1 u. w# ?

- q! ^* G: _8 m% n1 B  ~8.8 Circuit power limit measurement test

) \* A( Y/ \7 e8.8.1 This test shall be used to determine if the power available to a circuit under any loading condition,
. ^: U$ q. a% Y0 p7 E# [$ B. K- |& u) ?including short circuit, measured after one minute of operation exceeds a defined limit. For the purposes
) W# h5 H* F( C* C, P5 nof 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.

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