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http://bbs.angui.org/thread-104454-1-1.html
% W2 Z$ F6 I2 z& |. U3 u' S, L& CVaristors (VDR’s) across the mains
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Question:
% j) d) z2 y5 S+ i5 f1 dReports from different Testing Laboratories and clients expose essential differences in interpretation and testing practice between laboratories and/or Certification Bodies.$ y9 o3 E; U3 {" y, S
Actually, the practice of one Certification Body is now being a market factor.$ g' b+ G, H G3 i
Based on above concerns we ask for clarification:
) X; q$ k: u" ~( A3 `1 p1: Shall Cl. 19.11 be strictly followed or can solutions given under 2. be accepted.9 f$ B6 w. E. {$ l3 o% i6 J- }
2: Can any of the decisions (made by OSM/EE) be accepted?5 R6 \% N, L6 N
- A: VDR’s across the mains are accepted if the VDR is separately certified according to IEC 61051-1 or according to CECC 42200.; C- x6 m4 ?7 ~) G% |
- B: VDR across the mains with a protective device to guard against short-circuit is acceptable./ L- E. W( K2 C. B
- C: If A and B are acceptable, should, because of the fact that VDR’s may burn or burst during life-time due to an increasing temperature stress caused by increase of leakage current with a number of switching cycles in the VDR, a thermal interrupting device on the VDR connected in series with the VDR be required.$ @! y- ?5 e3 v8 d
Decision:
0 t" P* W/ |, I' G- x7 v1. VDR’s are not short-circuited if they are used within their manufacturer’s declared specification, when tested according to Sub-clause 19.11.2 of IEC60335-1(1991). @4 k# D: W( W( ^. b
2. VDR’s are short-circuited regardless of compliance with IEC61051-1, when tested according to Subclause 19.11.2 of IEC60335-1(2001).
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