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 & R( m9 J% b9 g* ^. F- [; X, a

Extra safety circuit equivalent to SELV or double/reinforced insulation

12

60570(ed.3);am1;am2 & 60570(ed.4) 5 f( X& K* S7 s; y- A# B! k

' J4 l; `  V3 ^) _' ]Standard(s):
IEC 60570 All editions
Subclause(s): 12
5 D7 \# M, ], \No. Year PDSH 0992 2010
/ R+ t3 Z& E5 o3 mCategory: LITE Developed by: ETF5 OSM/LUM
8 V3 [' ]0 J7 n( Z! E( dSubject:
Extra safety circuit equivalent to SELV or double/reinforced insulation
' T8 C5 |; y. m/ l1 W9 V; OKey words:
- SELV condition
/ o$ N8 p# Y* R  Q( e) G- Electronic means
; N; j* E& P, E$ p$ {9 M+ m" A" T- IEC 60364-4-41 / IEC 61140
; I  J/ b0 W) {, R2 q; aTo be approved at the 49th CTL Plenary Meeting, in 2012
; p5 F8 \5 ?6 Z% ]Question:
- |/ w, U) N: i& M1 yA 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
8 ?4 m' v# R) {' B% }) U7 `circuits, which are insulated from live parts by double or reinforced insulation. Due to the fact that both
; l8 r7 R8 A: |  @DALI systems (or similar systems) and control systems of electronic ballasts do not comply with the
requirements of double insulation, our client created an additional safety circuit between the bus-track and
* \5 x! D5 C& P7 nDALI system/electronic ballast. The extra safety circuit consists of six zener diodes (>50 V) and four
0 ^& ~4 K$ }$ y8 ?( Y) x0 `fuses (250 mA). The diodes guard the system to voltage higher than 50 V and the fuses protect the system
# [- D5 y, S9 ~against high currents. In this way SELV conditions are guaranteed.
Decision:
In principle the SELV condition can be reached by electronic means at least according to the standards
IEC 60364-4-41 and IEC 61140.