Information on the technical requirements for construction and certification of low and extra low voltage installations.


Private distribution systems

The Regulations formally allow the wiring rules to be used for private works, for example low voltage wiring of a shopping centre that would otherwise be classified as “works”. The same principles as those described under the low voltage installations section of this guide apply.


Templates for the Certificate of Compliance (CoC), Electrical Safety Certificate (ESC), and a combined CoC–ESC, are available from industry, including from the Electrical Workers Registration Board (EWRB). Alternatively, you can design your own certificates, provided that they meet the requirements set out in Regulations.

Remember that the changes do not apply to appliance repairs.

Certificate of Compliance and Electrical Safety Certificate templates.

Work that you are connecting yourself

If you are doing work, such as additions and alterations, that you will connect yourself, use a combined CoC–ESC.

When you have completed the work, test it, and then sign off the CoC section.

When you have connected the fitting and are satisfied that:

  • the polarity is correct,
  • the work has not affected the safety of the existing installation,
  • and it will be safe for use.

Sign off the ESC section and supply the certificate to your customer (this might be done via email) and file a copy. The filing can be done electronically and may be part of a certification package.

Work that requires Inspection

If you are doing work that requires inspection, but you are connecting it yourself, arrange the inspection, and check that the Record of inspection (RoI) verifies that the work is safe. Then before you carry out the connection check and complete the ESC section.

The inspector will be required to enter information on the work on the Electricity & Gas High-Risk database(external link), and you can check this if you wish by using a public search of the address where the work was done.

Work that you are not connecting yourself

If you are not doing the connection then you can use a combined CoC–ESC and strike out the ESC section or simply use a CoC.

The person doing the connection must complete the electrical safety certification (ESC) of the connection. In the case of a new installation, this could be the meter installer, or a lines worker employed by a network company. It might also be the inspector.

If you are the main contractor for the work, and have engaged the inspector and arranged connection, you can expect to get the copies of the RoI from the inspector and ESC and from the person doing the connection.

Work that is just connecting

If you are only doing a connection, you must verify:

  • the certification (CoC),
  • an inspection has been completed, and
  • and a compliant RoI has been issued.

Complete the safety checks yourself, before completing an ESC, and then provide the ESC to your client and file a copy.


Connection refers to the prescribed electrical work (PEW) that is the final step that will allow electricity to flow in the installation or part installation on which other PEW has been done.

Maintenance, repairs and replacements

If you are performing maintenance, repairs or replacements (in any installation) you only need to complete an ESC after you have completed the work, tested it, reconnected it, and are satisfied that your work has not adversely affected the safety of the installation.

Maintenance, repairs and replacements remain exempt from Certification via a CoC, and are now called “Low Risk Work”.

What requires inspection

The range of work requiring inspection is now called “High Risk Work” and remains the same except that work in Mines and work on Photovoltaic systems have been added.

Authentication Mark

All CoCs and ESCs are required to display the Authentication Mark.

Integration into business documents

You can also combine Certificates into business documents. An example would be an invoice for repairs or replacements where the Authentication mark and the necessary information has been added and signed off.

For further information, see our check lists for preparing certificates and details applying to inspections and RoIs.