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请问如下这个测试怎么做啊
4 _1 U) }' c5 x" o18 Limited Short-Circuit Test
1 r) X/ v7 @1 L0 z* y3 l) b+ t1 o18.1 General8 e, g& o5 ?0 |
18.1.1 Following the test specified in 18.2.1 or 18.3.1, a thermistor shall:
! e: C& J, w, L8 j7 s6 m: D% W5 l- na) Comply with the requirements in 11.1.2 or be in a permanently high resistance state; and% k1 A! S8 W1 Z/ Z5 \. y% L
b) Complete the test without igniting the cotton indicator or opening the ground fuse described in
' c( N8 W2 r- i( W18.1.4 and 18.1.5., W/ T8 n, E. z% J4 D6 n, G
18.1.2 When the results of the Limited Short-Circuit Test on the thermistor itself comply with 18.1.1, the c7 X' R2 W: H' F H
test is not required to be repeated during the investigation of the end product.
' ]" I8 J% z5 f, \18.1.3 Three samples of a control thermistor are to be subjected to this test. The test is to be conducted. M# }" U: H& E" |
at rated voltage (Vr).
( K9 C1 }% w, m7 s0 T18.1.4 A ground fuse is to be connected between the metal enclosure, metal mounting surface, or metal5 Y8 c: q0 S8 _, I
screen described in 18.1.5 and the unswitched line to indicate an arc-over to the enclosure or mounting
2 _3 K* v- S8 d# n* O: Isurface. Where each line is switched, the fuse is to be connected between the enclosure, mounting
) X8 j% u6 b% t) D) z" ^surface, or screen and the live pole least likely to arc to ground. The fuse is to be a 3.0 A nontime-delay
. I# c5 V7 t1 Dfuse having a voltage rating not less than the rated voltage (Vr) of the thermistor.
) o% ]% F* \) l) q2 J0 `18.1.5 Cotton not less than 12.7 mm (1/2 in) thick is to surround a metal screen enclosing the thermistor
6 z4 ~* K5 W/ n: Vat a distance not more than 12.7 mm from all parts of the thermistor.
% d( H* h5 _* ~8 P4 Q2 a18.1.6 The cotton is to be surgical cotton, such as commonly used for medical purposes. |
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