Business and enterprise – guidance

Electricity meter certification

Legally manufacture meters which are of the design originally approved and ensure they are verified to operate within the statutory limits.

Certification

Once an approval is granted, a manufacturer can submit meters, manufactured in accordance with the type approval, for certification. It is a requirement of the Electricity Act 1989 that all domestic meters used for billing purposes by a licensed electricity supplier must be certified to show that, when tested following manufacture/refurbishment, they conform to the original pattern approval and operate within the prescribed levels of accuracy.

Certification is performed by meter examiners appointed by Regulatory Delivery (RD) or by authorised examiners employed by manufacturers/repairers of electricity meters that have been authorised to self-certify. This process is described in detail in the Meters (Certification) Regulations (SI 1998/1566). This prescribes that all meters, following approval, be allocated a certification life (ie the time a meter is allowed to remain on the wall from initial certification).

Meters for industrial and commercial customers are either certified or the supplier reaches agreement with the customer for a meter with a similar level of accuracy to be fitted. Certification life is allocated by RD and is restricted to 10 years for newly approved induction meters and for periods of between 10 and 20 years for static meters. Certification lives greater than 10 years (for electronic meters) are subject to the submission and validation of a component reliability model based on the Siemens Norm SN29500.

Subsequent in-service surveillance monitoring through the national sample survey can result in the certification life of a meter type being either extended or reduced. When certification is required meters must be removed from service when the certification life expires.

Secondary metering

Meters need not be certified where the supplier does not hold a supply license. This provides for situations where the supplier might be a landlord selling electricity on to tenants, or a caravan park owner billing individual berth occupiers. However, a written agreement must be in place between the two parties to dispense with the requirement for certification and the meter owner is obliged to use an approved meter and keep the metrology of the meter accurate.

Self certification

The Meters (Certification) Regulations allow RD to authorise manufacturers and repairers of electricity meters to ‘self-certify’ meters that have been manufactured or repaired. Formal authorisations are issued to the manufacturer/repairer; these are subject to regular audits performed by independent meter examiners appointed by RD.

Manufacturers/repairers authorised to self-certify meters must comply with the strict conditions under which the authorisation is issued. If these are breached, RD has the sanction of withdrawing the authorisation (see Section 5(5)(c) of the Electricity Act 1989 and Paragraphs 3(3) and 4(3) of The Meters (Certification) Regulations SI 1998/1566).

Sealing

Prior to submission for certification meters will have a uniquely marked seal attached. A seal is used to provide security for the measuring elements of a meter from tamper, identify the manufacturer/repairer of the meter, the year of certification and the fact that the meter is certified. The seal can take the form of a crimped security seal on traditional meters or an indelible inscription on the meter case for sealed-for-life static meters.

If this seal is removed or tampered with in any way this should be reported to the supplier.

Contact

If you wish to speak to a member of staff please contact:

Electricity Metering Team

Utilities Team
Regulatory Delivery
Stanton Avenue

Teddington
Middlesex
TW11 0JZ