|
need to note the clause below:
. |! b* n* N5 p' x% D; MIEC60950:2 Y) L6 ~# ]! V, T" o' v
1.5.9.2 Protection of VDRs
$ U' n4 b. H& i! Y: s/ L0 UFor protection against
' ]4 [ Z% O2 w! C& @1 I) K− temporary overvoltages above the maximum continuous voltage,* @& [5 J: {0 H8 ? @/ v4 v' g' q
− thermal overload due to leakage current within the VDR, and
$ p2 q) [8 g1 ^4 G& ?; W− burning and bursting of the VDR in the event of a short-circuit fault,
' N3 J' D5 H/ s ^, aan interrupting means having an adequate breaking capacity shall be connected in series with, j- C, F4 v# @3 G: G; e$ b
the VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.
, z9 g R% {" G* ^; C P2 r( a/ {9 U" t/ G# Q( A( x2 T' e0 T
IEC60065:4 f; F2 x8 K3 ]# l- `$ [% k
– thermal stress3 G, F; J# U) P4 \, O) m
For apparatus with nominal MAINS voltage of <150 V, the apparatus and a test resistor$ F" d7 u, n; f& A4 z, p- d
connected in series with the apparatus shall be energised from an a.c. source of 250 V.6 W0 Q& ~# e* s- I/ r1 X
The voltage source shall be applied for 4 h or until the circuit path through the varistor+ f' @/ b7 v' O
opens for each of the test series resistance values: 2 000 Ω, 500 Ω, 250 Ω, 50 Ω. A
W% \5 l) l: E0 }" Nseparate apparatus shall be used for each resistor value, unless damage from the previous7 j! _# _+ C6 w" \5 B5 i
test has been repaired.8 e" m8 u0 k( Y- E- N a, o
At the end of each test, the apparatus shall comply with clause 11. |
|