Master Subtractive Metering Rectification

Looking at a meter

What is a Master Subtractive Meter?

A master-subtractive meter arrangement is a way of measuring your property’s electricity usage that’s no longer in use. It involves a ‘master’ meter at the point where electricity enters the property or properties, and subtractive meters further along the network. Subtractive meters are typically used to measure the usage of hot water systems, under floor heating, water pumps and sheds.

If you have a master/subtractive metering arrangement, your electricity usage is determined by deducting the reading on your subtractive meter from the reading on the master meter. The net figure is used by your retailer to calculate your energy bill.

Master sub metering diagram

What has changed in relation to Master Subtractive Metering configurations?

Under 2017 changes to the Australian Energy Market Operator rules, all electricity meters must display the actual meter reading for that premises. This means that Master Subtractive Meter arrangements are no longer permitted and must be replaced.

What is Essential Energy doing about the 2017 rule change?

Essential Energy is working to ensure all non-compliant master/subtractive meters are compliant with the 2017 ruling as soon as possible. The works required to correct the arrangement will be assessed on a case-by-case basis as the arrangement at each property is unique.

What do I need to do?

If your property has a master subtractive metering arrangement and needs to be corrected, we will contact you in writing.

Generally, the process to change your metering arrangement will follow the steps below:

  1. Essential Energy will write to you to inform you that you have a master subtractive metering arrangement that needs to be corrected, and to arrange a date to inspect your property to help determine the works required.
  2. Essential Energy will develop a method to correct your metering configuration and communicate that plan with you. If your premise is occupied under a lease arrangement, the owner of the premise will also be contacted.
  3. Works to change your metering configuration will be completed.
  4. Following completion of the works, Essential Energy will notify your retailer that your metering configuration has changed.

Please note: This is a broad overview of a complex matter. To discuss specific details, please contact us on 132391.