PDSH 992 Extra safety circuit equivalent to SELV or double/reinforced insulation

小米

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

PDSH 992 4 \+ I" l! ?( {$ j, t$ F

Extra safety circuit equivalent to SELV or double/reinforced insulation % T. ~0 M5 c* ^+ o/ D: c

12

60570(ed.3);am1;am2 & 60570(ed.4) 1 H1 b) Q/ ^! a/ M- S

  u7 s, {$ y. U: TStandard(s):
IEC 60570 All editions
Subclause(s): 12
3 M2 G# M" d# L6 pNo. Year PDSH 0992 2010
Category: LITE Developed by: ETF5 OSM/LUM
: @. s2 S  Q1 QSubject:
5 c: d+ A! F* ?0 XExtra safety circuit equivalent to SELV or double/reinforced insulation
; Y; o2 C5 D+ ~5 aKey words:
- SELV condition
- Electronic means
" a/ R: m% a1 c3 k" Z4 y- IEC 60364-4-41 / IEC 61140
' H( b' G* z, WTo be approved at the 49th CTL Plenary Meeting, in 2012
Question:
A client wants to combine a 230 V track system (according to IEC 60570) with a bus track system, which
tracks are accessible. Consequently the bus-tracks may be supplied by a SELV source only, or connected to
7 R+ [' [& _% v  m, dcircuits, which are insulated from live parts by double or reinforced insulation. Due to the fact that both
7 e! Z/ a! X+ i& F$ u5 K; P! f4 L; J  PDALI systems (or similar systems) and control systems of electronic ballasts do not comply with the
2 N, p0 n3 C' C) c7 F$ p) \requirements of double insulation, our client created an additional safety circuit between the bus-track and
7 ~$ R  q+ \1 M5 m9 DDALI system/electronic ballast. The extra safety circuit consists of six zener diodes (>50 V) and four
9 z5 d6 k- E6 yfuses (250 mA). The diodes guard the system to voltage higher than 50 V and the fuses protect the system
against high currents. In this way SELV conditions are guaranteed.
% I$ @+ z- ^3 P" rDecision:
In principle the SELV condition can be reached by electronic means at least according to the standards
IEC 60364-4-41 and IEC 61140.
3 t4 _. G' l" @$ Z* x8 {5 X