DSH 657 Characterizing the pollution degree of micro-environment within a sealed

admin

广东安规检测
有限公司提供：

小型摆管淋雨试验机

IPX5X6X7喷水试验机

1000L恒温恒湿箱

各种试验指现货

可程式恒温恒湿试验箱

水平垂直燃烧机

自动卷线器试验机

耐划痕试验机

各种灯头量规现货

灼热丝试验机现货

GB1002插头量规

IPX1-X7淋雨现货

IEC61347/UL935镇流器热试验箱

灯具防风罩

IK冲击试验机

UL498插头插座量规

VDE0620插头插座量规

稳定性试验台

家电温升测试角

针焰试验机现货

热电偶焊机现货

家电125mm试验指

E12灯头量规

无绳壶无绳电熨斗插拔寿命试验机

IEC60335试验指甲

DSH 657

Characterizing the pollution degree of micro-environment within a sealed device that has switching c ...

20.2.2

60730-1(ed.3);am1;am2 0 _& K' ]& s7 D1 H  m5 R

Question:
Clause 20.2.2 of IEC 60730-1 states that creepage distances for operational insulation shall be as specified in table 20.4 based on the material group and the pollution degree. What is the pollution degree of the micro-environment within a sealed control that has switching contacts?
: b" w* P6 o. U" x0 h& h9 EExample: Bimetal temperature sensing device. IEC 60730-2-9 does not give any additional guidance. Even though the micro-environment is sealed (by construction) from influence by the external environment, the pollution situation can be conductively contaminated due to ionization of the contact material and out-gassing of the plastic parts that may be near the switching
mechanism. This is very similar to sealed relays covered under IEC 61810-1. In this standard, creepage distances inside a relay are specified in accordance with pollution degree 2.
. @$ F4 T2 J: g% w0 uDecision:
; V+ N  c! T9 Q' J3 ]# nFor controls, an endurance test and a high voltage test in combination are required. If sealed contacts of a control have passed the endurance test and the high voltage test, it could be assumed that the pollution and the ionized gases in the sealed control does not influence the creepage and clearances of the control. Therefore pollution degree 2 in accordance to Annex N (normative) of IEC 60730-1 could be defined.
+ p& V5 H( x% b

& y9 V: B/ z4 Y) Q