DSH 526 Point on wave closing
http://decisions.iecee.org/icons/ecblank.gif DSH 526
Point on wave closing
9.3.7.3
62019(ed.1)
Standard: IEC 62019: 1999
Sub clause: 9.3.7.3
Sheet No. DSH- 526
Subject: Point on wave closing
Key words: - short circuit test - point on voltage wave
Decision taken at 40th CTL meeting 2003
Question:
The issue concerns IEC 62019: 1999 (Auxiliary contact units) test procedure 9.3.7.3 in the test at
conditional short-circuit current (9.3.7). SC 23E is concerned that there may be discrepancies in test
results made by different test stations, or at different times by the same test station due to the short
circuit being initiated at different points on the voltage wave.
Rationale:
At the meeting held in Beijing, SC 23E has asked that the improvement that they have made to the
standard be used by the CTL, as it will improve the repeatability of tests. According to IEC procedure
for technical work, this modification can only be introduced in the maintenance of IEC 62019, which
may imply some years before being endorsed in revised publication.
Decision:
In performing the test of clause 9.3.7.3 of IEC standard 62019, the following revised test method
shall be used:
The procedure requires that the contact unit, in the closed position, be subject three times to short
circuit, which is cleared by a short circuit protective device installed in series. Clause 9.3.7.3
specifies three operations. For the first operation, the making switch is synchronized with respect to
the voltage wave so that the circuit is closed on the point 0° on the wave. This point is then shifted by
30° for the second operation and to 60° for the third operation.
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