IEC 62053-23 pdf free download
IEC 62053-23 pdf free download.Electricity metering equipment (a.c.) – Particular requirements – Part 23: Static meters for reactive energy (classes 2 and 3).
7.2 Influence of short-time overcurrents
Short-time overcurrents shall not damage the meter. The meter shall perform correctly when back to its initial working condition and the variation of error shall not exceed the values shown in Table 3.
The test circuit shall be practically non-inductive and the test shall be performed for polyphase meters phase-by-phase.
After the application of the short-time overcurrent with the voltage maintained at the terminals, the meter shall be allowed to return to the initial temperature with the voltage circuit(s) energized (about 1 h).
a) Meter for direct connection
The meter shall be able to carry a short-time overcurrent of 30 ‘max with a relative tolerance of +0 % to —10 % for one half-cycle at rated frequency.
b) Meter for connection through current transformer
The meter shall be able to carry for 0,5 s a current equal to 20 ‘max with a relative tolerance of +0 % to —10 %.
NOTE This requirement does not apply to meters having a contact in the current circuits. For this case, see appropriate standards.
The test shall be carried out as follows: After the voltage circuits have been energized at reference voltage for at least 1 h for class 2 and 3, without any current in the current circuits, the maximum current shall be applied to the current circuits. The meter error shall be measured at sinφ = 1 immediately after the current is applied and then at intervals short enough to allow a correct drawing to be made of the curve of error variation as a function of time. The test shall be carried out for at least 1 h, and in any event until the variation of error during 20 min does not exceed 0,2 %.
8 Accuracy requirements
The tests and test conditions given in IEC 62052-11 apply.
8.1 Limits of error due to variation of the current
When the meter is under the reference conditions given in 8.5, the percentage errors shall not exceed the limits for the relevant accuracy class given in Tables 6 and 7.The difference between the percentage error when the meter is carrying a single-phase load and a balanced polyphase load at basic current ‘b and sinq) = I for direct connected meters, respectively at rated current I and sinç = 1 for transformer operated meters, shall not exceed 2,5 % and 3,5 % for meters of classes 2 and 3 respectively.
NOTE When testing for compliance with Table 7, the test current should be applied to each measuring element in sequence.
8.2 Limits of error due to influence quantities
The additional percentage error due to the change of influence quantities with respect to reference conditions, as given in 8.5, shall not exceed the limits for the relevant accuracy class given in Table 8.
8.2.1 Tests of the influence of d.c. component in the current circuit
The tests of the influence of d.c. component in the current circuit shall be made with the circuit shown in Figure A.1 or with other equipment able to generate the required wave-forms, and the current wave-forms as shown in Figure A.2.
The variation in percentage error when the meter is subjected to the test wave-form given in Figure A.2 and when it is subjected to the reference wave-form shall not exceed the limits of variation given in Table 8.
NOTE The values given in the Figures are for 50 Hz only. For other frequencies the values have to be adapted accordingly.
8.2.2 Continuous magnetic induction of external origin
The continuous magnetic induction may be obtained by using the electromagnet according to Annex B, energized with a d.c. current. This magnetic field shall be applied to all accessible surfaces of the meter when it is mounted as for normal use. The value of the magneto-motive force applied shall be 1 000 At (ampere-turns).
8.3 Test of starting and no-load condition
For these tests, the conditions and the values of the influence quantities shall be as stated in 8.5 except for any changes specified below.
8.3.1 Initial start-up of the meter
The meter shall be functional within 5 s after the reference voltage is applied to the meter terminals.IEC 62053-23 pdf download.
