Cathodic protection systems
What are cathodic protection systems?
Installation and design
Testing
Recordkeeping requirements
What are cathodic protection systems?
Cathodic protection systems are complex and it is recommended that you seek the assistance of a consultant or fully trained person in the installation, operation and testing of these sysytems. For further information, contact the Australasian Corrosion Association (non-Queensland Government link).
Cathodic protection systems are widely used, particularly with engineering structures such as building reinforcement and buried metallic pipeline and cables.
Cathodic protection devices protect structures and metalwork from corrosion, making the metal surface to be protected by a cathode element in a path of electric current, encouraging corrosion to form elsewhere in the circuit in a less critical or cheaper (anode) material.
These systems are regulated by Part 11 of the Electrical Safety Regulation 2002 (PDF, 1 MB).
Some cathodic protection systems are exempted from the Electrical Safety Regulation 2002. These include:
- fishing equipment;
- systems installed on a floating mobile structure; and
- some offshore structures or internal surface of an item covered by Australian Standard AS2832.4 Cathodic protection of metals - Internal surfaces.
Part 11, Division 2 of the Electrical Safety Regulation 2002 also details particular provisions that cover:
- the installation and design of cathodic protection systems;
- the operating requirements of cathodic protection systems;
- the testing requirements of cathodic protection systems;
- the registration of these systems.
Under the Electrical Safety Regulation 2002 all cathodic protection systems capable of delivering a current greater of 0.25A must be registered.
These systems must be periodically tested and test results kept.
They must be operated within specified electrical limits.
Installation and design
Section 173 of the Electrical Safety Regulation 2002 states that at least 60 days notice must be given before a system is installed.
The applicable standard for cathodic protection, AS 2832 series (Cathodic protection of metals) (non-Queensland Government link), must be adhered to in the system’s design and installation.
Operating requirements stipulated in Section 175 of the Electrical Safety Regulation 2002 are:
- appropriate testing of system;
- issues of interference mitigation satisfied;
- operated within AS 2832 series; and
- registered as required.
Section 182 of the Electrical Safety Regulation 2002 specifies electrical limits concerning the voltage applied, the maximum current that can be used and changes in potential to ground.
Testing
Testing prior to commencing operation
All cathodic protection systems must be tested – even those that are not required to be registered. This testing should be performed within 90 days of commencing operation.
Systems required to be registerd must be tested within 90 days of lodging the application. The Electrical Safety Office may allow a longer period upon request.
All tests must include:
- interference tests on all foreign structures for the system; and
- maximum voltage checks on water based or marine environment systems.
Testing should be based on maximum operating current values as stated on the application.
It is the responsibility of the owner of the system to:
- arrange testing;
- provide all the facilities; and
- bear all costs associated with testing.
Section 176 of the Electrical Safety Regulation 2002 provides more information on the testing of cathodic protection systems prior to commencing operation.
Find out how to register a cathodic protection system.
Further testing during the operation of the system
Interference tests need to be repeated when:
- requested by the Electrical Safety Office;
- the system or me thod of operation is changed; or
- an anode forming part of the system is replaced.
Testing as part of regular maintenance
Cathodic protection systems are also required to be regularly tested as a part of their operation. This is in accordance with the cathodic protection standard AS/NZS 2832 series as amended.
These tests include:
- system operation checks;
- cathodic protection potential surveys;
- equip me nt maintenance checks; and
- structure inspections.
The owner must provide access to the system and provide facilities to further test the system if reasonably required by the Electrical Safety Office.
All costs (including indirect/overhead costs) incurred by the Electrical Safety Office in carrying out such testing must be paid for by the system owner if it is found to be non-compliant.
More information is provided in Section 181 of the Electrical Safety Regulation 2002.
Recordkeeping requirements
Test records must be kept for ten years if:
- the system is an impressed current cathodic system; or
- the system is a sacrificial system that has a total anode mass of more than 25kg.
Last updated October 12, 2005