Electricity meters, current transformers and voltage transformers.

The Swedish Board for Accreditation and Conformity Assessment’s Regulations on measuring systems for measuring transmitted electricity

Regulations on measuring systems for measuring transmitted electricity and regulations on periodic inspection of active electrical energy meters are already in place today (STAFS 2009:8 and STAFS 2009:9). These have previously been notified as technical rules. The draft regulations include the following amendments to the existing provisions.

• The scope that applied to STAFS 2009:9 is being extended by removing the 63 A limit. As a result, new test points for category 1 electricity meters are being introduced and the maximum permissible error is being tightened for category 1 electricity meters above 63 A approved under the regulations transposing the Measuring Instruments Directive. A further consequence is that the maximum permissible error in Table 2 of the Annex to STAFS 2009:9 shall also relate to category 1 electricity meters above 63 A which have not been approved under the regulations transposing the Measuring Instruments Directive.
• A decision rule is being introduced for inspection related to measurement uncertainty, for all categories of measuring systems.
• The requirement to maintain a compilation of inspection reports for statistical control is being removed.
• A traceability requirement is being introduced for the evaluation that is to be conducted for electricity meters (category 3-5) and instrument transformers (category 2 to 5).
• The provision on normal operating conditions for category 2 to 5 metering systems is being amended so as to further clarify how the normal operating conditions are to be determined.
• An inspection body, which is accredited by an accreditation body other than Swedac and intends to carry out inspections, shall inform Swedac of this.
• The draft regulations propose several further amendments in order to ensure regulatory consistency, including with regard to the coverage probability and the relationship between the extent of measurement uncertainty and the maximum permissible error.

The draft relates to inspection of in-service measuring systems and in some cases to inspection when measuring systems are being put into service. Such inspection shall be carried out by an inspection body accredited for the task under Regulation (EC) No 765/2008 of the European Parliament and of the Council. The draft regulations also contain certain requirements for measuring systems and there is no mutual recognition clause for these requirements. This is because some electricity meters are covered by the Measuring Instruments Directive (2014/32/EU) and the draft does not contain specific requirements for other electricity meters and transformers. Instead, the requirements for other electricity meters and transformers relate to the  fact that the measuring system included in these electricity meters and transformers must, as a whole, meet certain measurement accuracy requirements. Any meters and transformers may be used as long as the required measurement accuracy is met. There are also requirements for recording measured values and adaptation. Any measuring system that meets the requirements for recording measured values and adaptation is accepted.

The draft does not contain Swedish national provisions in relation to the Measuring Instruments Directive (Directive 2014/32/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments) and does not include any requirements that are more stringent or more comprehensive than those laid down in that Directive.