IEC 60358-3-2013 pdf Coupling capacitors and capacitor dividers – Part 3: AC or DC coupling capacitor for harmonic-filters applications

8.3 Type tests Clause 8.3 of IEC 60358-1 :201 2 is applicable with the following additions: 8.3.300 8.3.300.1 Type tests for filter capacitor and tuning device Type tests for filter capacitor a) High frequency capacitance and equivalent series resistance (1 0.300.1 ) b) Measurement of the stray capacitance and stray conductance of the low voltage terminal (1 0.300.2) 8.3.300.2 Type tests for tuning device a) Impulse voltage test (1 0.301 .1 )
10.300 10.300.1 Test on capacitor High frequency capacitance and equivalent series resistance The measurements shall be carried out on a capacitor stack or on a capacitor unit. The capacitance and the equivalent series resistance shall be measured at the two temperatures equal to the limits of the temperature category and at a temperature within the standard range for testing (IEC 60358-1 :201 2, Clause 7), at frequencies specified from the purchaser. The purchaser specifies the measuring frequencies and the acceptance criteria in terms of capacitance variation in function of the filter capability The equivalent series resistance has an influence on the quality of the filter and on the thermal withstand of the capacitor; the acceptance criteria will then be defined between purchaser and manufacturer. For high frequency characteristics and measuring methods, see Annex BB. NOTE In the case of practical difficulties in carrying out the measurements at the limits of the temperature category, the purchaser and the manufacturer may agree on measurements over a smaller temperature range, or on measurements performed on a model capacitor containing a limited number of elements. 10.300.2 Measurement of the stray capacitance and stray conductance of the low voltage terminal The measurements shall be carried out either on a bottom unit or on a model representative of the bottom part of the capacitor under consideration. This model shall include the earth terminal, the metal parts (e.g. flanges) permanently connected to it, and the low voltage terminal with at least one element connected to it and placed in its proper position. If a model is used, it shall be filled with the insulating liquid used for the capacitor. The values of the stray capacitance and the stray conductance, measured at frequencies specified from the purchaser, shall not exceed 200 pF and 20 µS respectively.