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need to note the clause below:. V2 i$ ]. b% X" X& q, @9 p6 v+ m
IEC60950:
' i, [4 J( P. q6 O7 R6 r" s8 t1.5.9.2 Protection of VDRs
0 s4 @2 S3 g! I/ v8 RFor protection against
5 Q# Z# `2 Q8 L+ l; Z− temporary overvoltages above the maximum continuous voltage,; M' `/ T: @3 d; }, H9 o
− thermal overload due to leakage current within the VDR, and. `, a; P3 \/ `) @
− burning and bursting of the VDR in the event of a short-circuit fault,6 E( v1 i( b8 X7 L( F: _+ K! R; B9 T
an interrupting means having an adequate breaking capacity shall be connected in series with
( H- R: w% J( m3 bthe VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.. v; I) f. S2 }- `0 _
4 x) s0 M4 B7 C- o1 h! F2 o
IEC60065:
% a# x5 x4 m2 w8 E' D( d$ w– thermal stress
/ t1 b* \# F% [5 KFor apparatus with nominal MAINS voltage of <150 V, the apparatus and a test resistor
; Q& Y" Z0 U" J# V3 cconnected in series with the apparatus shall be energised from an a.c. source of 250 V.5 k+ e& ?" O" \; Q4 ~$ Y, S( ?$ \
The voltage source shall be applied for 4 h or until the circuit path through the varistor% \6 ?( Q+ D4 ~. j/ L
opens for each of the test series resistance values: 2 000 Ω, 500 Ω, 250 Ω, 50 Ω. A# U6 z j+ Z6 Z! l* v
separate apparatus shall be used for each resistor value, unless damage from the previous( ^7 C( e( h7 n
test has been repaired.
5 g0 d/ S G& }9 B& BAt the end of each test, the apparatus shall comply with clause 11. |
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