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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- Y: \# ]% C" @0 P) [
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) B9 K( D) c6 ~' c
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?% B7 D+ Y9 [2 F* T- n9 j N$ |% M
3.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?
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, p4 L' s5 y- N+ ? I8.7.2 Component failure test
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* }4 r7 \6 f' O& X- g# Y8.7.2.1 A unit having components such as resistors, semiconductor devices, capacitors, and the like shall( g3 R- P. U* n- m! D4 F, \+ C
not exhibit a risk of fire or electric shock when a simulated short circuit or open circuit is imposed. In
. B3 D/ Q& M6 rpreparation for component failure tests, the equipment, circuit diagrams, and component specifications, `$ g* f% q1 V' ~
are examined to determine those fault conditions that might reasonably be expected to occur. Examples) s9 V% y C% }
include: short-circuits and open circuits of semiconductor devices and capacitors, faults causing open* P3 W7 @/ ?% u8 H
circuits of resistors and internal faults in integrated circuits.) j& s. N0 C5 _8 p) W" L
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5 u- Z: D3 a4 x% F; l' P# _Exception No. 1: Circuits in which maximum power levels have been determined to not exceed 50 W need
8 E8 t- a; q5 ^, }5 d6 \not be evaluated for component failure.
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Exception No. 2: Devices supplied by a source operating within the limits for risk of fire and electric shock/ v) [% \& T! D8 D2 u
need not be subject to this test./ m* q/ F9 `: t9 @6 Z
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8.8 Circuit power limit measurement test
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8.8.1 This test shall be used to determine if the power available to a circuit under any loading condition,9 I6 F8 S# a! m/ j
including short circuit, measured after one minute of operation exceeds a defined limit. For the purposes
, }6 D6 {; `- f& r+ o" }. Cof this test, the limit (for example, 15W or 50W) is referred to as PLIMIT. This test is applied to a circuit
9 U7 q) s7 r% U6 _; m6 U/ q. |2 G4 V(under evaluation) to determine if it has a power draw of PLIMIT or less.4 K- R1 u) E: l- E) d% t( g+ z$ r/ _
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