IEC 60947-1-2020 pdf free download

IEC 60947-1-2020 pdf free download.Low-voltage switchgear and controlgear — Part 1: General rules
Appareillage a basse tension — Partie 1: Règles générales.
For transient recovery voltages, in the case of breaking capacity tests under normal load and overload conditions, values shall be specified in the relevant product standard.
9.3.3.5.2 Test circuit
a) Figure 3, Figure 4, Figure 5 and Figure 6 give the diagrams of the circuits to be used for the tests concerning
— single-pole equipment on single-phase AC or DC (Figure 3);
— two-pole equipment on single-phase AC or DC (Figure 4);
— three-pole equipment or three single-phase equipment on three-phase AC (Figure 5);
— four-pole equipment on three-phase four-wire AC (Figure 6);
A detailed diagram of the circuit used for the test shall be given in the test report.
b) The prospective current at the supply terminals of the equipment shall be not less than 10 times the test current or 50 kA, whichever is the lower.
C) The test circuit comprises the supply source, the equipment D under test and the load circuit.
d) The load circuit shall consist of resistors and air-cored reactors in series. Air-cored reactors in any phase shall be shunted by resistors taking approximately 0,6 % of the current through the reactor.
However, where a transient recovery voltage is specified, instead of the 0,6 % shunt resistors, parallel resistors and capacitors shall be included across the load, the complete load circuit being as shown in Figure 8.
NOTE I For DC tests where L/R> 10 ms an Iron-cored reactor can be used with series resistors, If necessary,
verifying with an oscilloscope that the L/R value is as specified %) and that the time required to obtain
95 % of the current made is equal to 3 x L/R ± 20 %.
Where a transient inrush current is specified (e.g. utilization categories AC-5b, AC-6 and
DC-6), a different type of load may be specified in the relevant product standard.
e) The loads shall be adjusted to obtain, at the specified voltage:IEC 60947-1-2020 pdf free download.