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Kilowatt Hour Meters (kWhr)

Kilowatt Hour Meters (kWhr)

There are a lot of kWhr meters available on the market, but its not that well known that an electricity meter intended to be used for trade or billing purposes must be:

  • Pattern approved; and
  • Verified.

This applies to electricity kilowatt hour meters installed from 1 January 2013 and measuring less than 750 MWh per year.

If you need assistance in checking if your kWhr meter is approved and connected correctly contact the team at Elexacom on 08 93304592.


Q1. What are the requirements that were introduced on 1 January 2013 for electricity meters?

A. The National Trade Measurement Regulations 2009 were amended to remove an exemption for electricity meters measuring less than 750 MWh per annum. The two key requirements you should know from this change are that electricity meters used for trade must now be:

  • of an approved pattern; and
  • verified.

Q2. How do you determine or define whether an electricity meter measures less than 750 MWh per annum?

A. In Australia, the majority of electricity meters used for trade measure well under 750 MWh per annum. The typical household consumption is 5 to 10 MWh per year. For meters measuring significantly larger quantities of energy, the National Measurement Institute (NMI) would consider State and Territory legislation to classify the meter. For instance, a meter would not be considered as measuring less than 750 MWh per annum if it is defined as a type 3 installation (or lower) under the National Electricity Rules.

Q3. Can I repair or adjust an electricity meter installed prior to 1 January 2013?

A. Yes. The metrological seals may be broken to replace batteries, or to make other appropriate minor repairs or adjustments. However, a meter must not be substantially modified which would in effect create a different meter design or pattern.

Q4. What are the obligations for the repair or adjustment of meters installed on or after 1 January 2013?

A. Following any repair or adjustment to a meter that affects the metrological performance, the meter must be verified before subsequent use for trade. If the metrological seal is broken, for instance to replace a battery, the meter must be verified. Adjustments or repairs that do not affect the metrological performance, such as replacing a battery that is not sealed with a metrological seal, are permitted without subsequent verification.

Q5. Can I relocate an electricity meter installed prior to 1 January 2013?

A. Yes, an electricity meter installed prior to 1 January 2013 may be relocated.

Q6. Can I relocate an electricity meter installed on or after 1 January 2013?

A. Yes, provided that you comply with the obligations detailed in Q4 upon repair or adjustment.

Q7. What models of electricity meters are pattern approved?

A. Approved patterns of kilowatt hour meters are listed on the NMI Website.

Q8. What about software/firmware updates for pattern approved kilowatt hour meters?

A. Software/firmware changes are permitted, provided they do not affect the metrological performance of the meter. Any changes that do affect the metrological performance must be submitted by the certificate owner (typically the manufacturer) to NMI for approval.

Q9. Can I install and use for trade a meter that has an expired or cancelled Certificate of Approval?

A. Yes, provided that:

  • the Certificate of Approval was valid at the time the meter was manufactured; and
  • the meter is verified.

If a meter had a valid Certificate of Approval at the time it was manufactured, then the meter is always considered to be of an approved pattern, except in the (rare) case a pattern approval is withdrawn.

Q10. We operate a building/site with multiple meters, for example, within a university, shopping centre, airport, caravan park, marina, residential site or commercial site. We have an approved and verified meter supplying electricity to the building/site and multiple sub-meters used for billing. Do the sub-meters need to be pattern approved and verified?

A. Yes. The requirements apply to all electricity meters used for trade, regardless of whether they are market meters or sub-meters, kilowatt hour meter kWhrand who owns or operates them. The meter is considered in use for trade if the measurement is used to determine the amount to pay for a transaction. This includes cases where the sub-meters are used only to determine the proportion of the total energy. This is because the accuracy of all meters affects the amount to be paid.

Q11. Can I verify a meter that is not of an approved pattern?

A. No. Verification has a particular meaning under the National Measurement Act and only meters of an approved pattern may be verified.

Q12. Who can verify  kilo watt hour meters?

A. Electricity meters must be verified in accordance with the National Instrument Test Procedures for Utility Meters (NITP 14). Electricity meters may only be verified by an appointed Utility Meter Verifier.

Q13. What transitional arrangements were there for meters that were not yet approved and verified near 1 January 2013 (grandfathering)?

A. In the period around transition, NMI accepted applications to grandfather meters held in stock.  This means NMI granted Certificates of Approval, and Certificates of Verification (see A 14 and 15 below)..

Q14. How do I know if a Certificate of Approval is a grandfathering certificate?

A. The approval numbers for grandfathering certificates start at 14/2/150. These certificates also include the following words (or similar): ‘This approval does NOT permit the verification of new instruments’. Grandfathering certificates are also listed as expired.

Q15. How do I know if my specific meter is grandfathered and can be used for trade?

A. You would need to confirm there is a Certificate of Verification that lists the individual meter by serial number.  These certificates should be provided by the meter supplier.

If you need help to check if your kilowatt hour meters are connected correctly and are approved, call the team at Elexacom we would be happy to assist.