OSM_EE 13.7

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小型摆管淋雨试验机

IPX5X6X7喷水试验机

1000L恒温恒湿箱

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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

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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

Question:
Table 2 of 60950-22 gives examples how to reduce the pollution degree from 3 to 2 inside the enclosure of an outdoor enclosure.
One method is to use an enclosure meeting IP54.
In EN 60529, for Dust Testing involving first characteristic numerals 5 and 6, its sub-clause 13.4 (Dust test for first characteristic numerals 5 and 6) states, Enclosures are of necessity in one of two categories:
Category 1: Enclosures where the normal working cycle of the equipment causes reductions in air pressure within the enclosure below that of the surrounding air, for example, due to thermal cycling effects.
* a7 A: w) R( o8 @Category 2: Enclosures where no pressure difference relative to the surrounding air is present.
6 H. X$ ]: S' ]* e; q2 B+ u2 g* i7 AAdditionally, in 13.5.1 is stated, “The enclosure shall be deemed category 1 unless the relevant product standard for the equipment specifies that the enclosure is category 2.”
! F( Q+ f2 o4 pEN 60950-22 does not mention anything about the enclosure category – does this mean that only IP5X tested according to category 1 is acceptable?
) `8 b0 t7 _" g& m+ i, gDecision:
* @$ Q. E9 E5 C. f" ~/ pOutdoor Enclosure. Since an outdoor enclosure does not consist of complete assembly, for IEC 60529 IP dust testing, the test method for Category 1 should be followed.
: R$ X) T% U9 M/ F6 M3 s, ~Outdoor Equipment. The test method, pressure to be applied - Category 1 or Category 2 should be determined based on:
3 c1 n: H# e2 I& U$ f[a] Does the product have an environmental/air handling system? (e.g fan, ventilation valve)
+ i+ i" Z+ w" W& P Is the product a sealed device with no internal environmental controls?
4 a4 y$ p* W& P2 S/ t0 [' `If a complete system with air handling system, testing should be based on the actual pressure differential in the equipment rather than that specified for category 1. For equipment with no environmental controls and air handling,category 2 method should be followed.
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