标题: PTC UL1434标准 [打印本页] 作者: 琥珀流云 时间: 2017-10-17 15:50 标题: PTC UL1434标准 请问如下这个测试怎么做啊 & _( [8 d% t5 Y18 Limited Short-Circuit Test) I; p8 g$ x Y7 ]2 u6 v
18.1 General, ?7 b) U5 N; D( y7 p# E; ]
18.1.1 Following the test specified in 18.2.1 or 18.3.1, a thermistor shall:, V2 W+ A) r" D$ w% i7 t
a) Comply with the requirements in 11.1.2 or be in a permanently high resistance state; and- d# |* R% F1 ~+ @ U
b) Complete the test without igniting the cotton indicator or opening the ground fuse described in7 i% X; v9 l7 m
18.1.4 and 18.1.5. 7 |! W9 x4 {0 \+ D, `9 f18.1.2 When the results of the Limited Short-Circuit Test on the thermistor itself comply with 18.1.1, the 9 Q. O. t3 p( N& c: Rtest is not required to be repeated during the investigation of the end product. ; f. b% C/ B. n$ T0 D0 {18.1.3 Three samples of a control thermistor are to be subjected to this test. The test is to be conducted - n! p2 o1 `" I$ J0 ?4 l8 eat rated voltage (Vr). 6 W; Y, y2 [; K7 k4 G: D/ f18.1.4 A ground fuse is to be connected between the metal enclosure, metal mounting surface, or metal / d& O* }- T* \: mscreen described in 18.1.5 and the unswitched line to indicate an arc-over to the enclosure or mounting 0 @7 R: s& c7 S* fsurface. Where each line is switched, the fuse is to be connected between the enclosure, mounting 4 ?. G+ |5 ~7 [- f( X( {5 d$ Qsurface, or screen and the live pole least likely to arc to ground. The fuse is to be a 3.0 A nontime-delay: D' F: u+ S, d, q
fuse having a voltage rating not less than the rated voltage (Vr) of the thermistor. ( `% O# H& V- l+ \18.1.5 Cotton not less than 12.7 mm (1/2 in) thick is to surround a metal screen enclosing the thermistor( v5 C% O# g) V% [$ P/ U! ?/ K) I
at a distance not more than 12.7 mm from all parts of the thermistor./ f* p0 b3 m2 l6 A8 C0 j" G/ V3 }% X& y
18.1.6 The cotton is to be surgical cotton, such as commonly used for medical purposes.