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need to note the clause below:2 c, [% y h7 }) \/ ]2 H
IEC60950:
: g- L; a+ H" c7 Z5 C2 U9 z+ e1.5.9.2 Protection of VDRs
H9 v" T8 V# |2 ^$ X' r9 vFor protection against( o% e, |6 R+ U9 i" t1 V# X
− temporary overvoltages above the maximum continuous voltage,5 _- z& H* A1 ]- W+ k/ M
− thermal overload due to leakage current within the VDR, and
$ `# r) q( A) @0 Y+ K. {− burning and bursting of the VDR in the event of a short-circuit fault,
1 H( ]$ P/ _* M/ b$ Kan interrupting means having an adequate breaking capacity shall be connected in series with
( w- O ]5 {% t! ~ G$ o$ ~, U- rthe VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.
. K9 y8 ]1 x' Z& b/ x( V$ W* a$ M: l1 O% X! J/ E
IEC60065:$ ~+ R' |# }3 H. ?; W5 }# m) d
– thermal stress
- V# G1 s; n3 `, c7 _For apparatus with nominal MAINS voltage of <150 V, the apparatus and a test resistor
, ]5 Q7 A6 Y/ ]$ n; v$ A& econnected in series with the apparatus shall be energised from an a.c. source of 250 V. u A4 r+ X- l
The voltage source shall be applied for 4 h or until the circuit path through the varistor
2 m( N# G/ r& _' Y" a9 nopens for each of the test series resistance values: 2 000 Ω, 500 Ω, 250 Ω, 50 Ω. A# i& c; Q- R& V* P2 x# r8 B
separate apparatus shall be used for each resistor value, unless damage from the previous3 }0 Y: X8 `# R$ s) r3 {1 B* A
test has been repaired.
/ C3 v6 `6 w+ @At the end of each test, the apparatus shall comply with clause 11. |
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