IEC 62058-21 pdf download – Electricity metering equipment (AC) – Acceptance inspection – Part 21: Particular requirements for electromechanical meters for active energy (classes 0,5, 1 and 2)
1 Scope
This part of lEC 62058 specifies particular requirements for acceptance inspection of newlymanufactured direct connected or transformer operated electromechanical meters for activeenergy (classes 0,5,1 and 2) delivered in lots in quantities above 50. The method ofacceptance of smaller lots should be agreed upon by the manufacturer and the customer.
The process described herein is primarily intended for acceptance inspection between themanufacturer and the purchaser.
NOTE lt can also be used for other purposes, for example to support initial verification.2Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 62058-11:2008，Electricity metering equipment (a.c.) – Acceptance inspection – Part 11:General acceptance inspection methods
ISO/IEC GUIDE 98:1995,Guide to the Expression of Uncertainty in Measurement
3Terms, definitions, symbols and abbreviations
For the purposes of this document,the terms，definitions，symbols and abbreviations ofIEC62058-11 apply.
4Test conditions
4.1Place of inspection
Subclause 5.15 of lEC 62058-11 applies.
4.2Reference conditions
The tests shall be carried out under the following conditions:
4.3Uncertainty of measurement of percentage error
The measuring process shall be such that the uncertainty of the measurement of thepercentage error should not exceed 1/5 th of the limit of percentage error for the given testpoint at reference conditions.
For determining the uncertainty of measurement,see lSo/EC GUIDE 98.
lf the uncertainty exceeds this limit,then inspection by variables cannot be used. Onlyinspection by attributes will be possible, and the limits of percentage error shall be correctedusing the following formula:
ecor (I,cosp)= 6/5·e(I,cosp)-U
where:
.e(I,cos(p) is the limit of percentage error for the given test point at reference conditions;. U is the measurement uncertainty.
EXAMPLElf, for a given test point, the limit of percentage error at reference conditions ise(I,cos (p)=±2% ; and
U = 0,5 %; then
ecwn(I , cos ()=士(6/5·2,0-0,5)=士1,9% .
Instead of the original limit, this corrected limit applies.
Table 3 gives percentage error limits corrected with uncertainty of measurement,using theformula above.
IEC 62058-21 pdf download – Electricity metering equipment (AC) – Acceptance inspection – Part 21: Particular requirements for electromechanical meters for active energy (classes 0,5, 1 and 2)
