Working on impressed current corrosion protection systems

Fact Sheet 10 September 2021

This Fact Sheet provides clarification on the requirements of the Work Health and Safety Regulation 2017 (WHS Reg) regarding working on impressed current cathodic protection (ICCP) systems.

This information may be subject to change.

Background

The definition of ‘electrical equipment’ under clause 144 of the WHS Reg includes any apparatus, appliance, cable, conductor, fitting, insulator, material, meter or wire that is part of an active ICCP system within the meaning of AS 2832.1–2015 (Cathodic protection of metals—Pipes and cables).

Clause 161 of the WHS Reg requires a person conducting a business or undertaking to ensure that electrical work on energised electrical equipment is carried out by a ‘competent person’ who has tools, testing equipment and personal protective equipment.

Clause 5 of the WHS Reg defines a competent person for electrical work on electrical equipment as a person who is authorised under the Home Building Act 1989 to do electrical wiring work.

Clarity is provided herein on whether the structure being protected by the ICCP system (hereinafter referred to as the ‘primary structure’) is considered a ‘conductor’ and/or ‘material’ that is part of an ICCP system, and therefore included within the definition of ‘electrical equipment’. Subsequently, clarity is also provided on what types of work on ICCP systems, including painting or operation of pipeline valves, can be undertaken by persons other than a person who is authorised under the Home Building Act 1989 to do electrical wiring work.

Primary Structures

A primary structure, in relation to a corrosion protection system, herein means the structure that the corrosion protection system is installed to protect.

A primary structure in relation to an ICCP system does not fall within the definition of electrical equipment clause 144 of the WHS Reg where the current supplied to the primary structure is from an extra low voltage (ELV) source. ELV is conventionally ≤ 50VRMS AC or ≤ 120V ripple free DC according to AS/NZS 3000 Wiring Rules.

Working on ICCP systems

NOTE: work on energised electrical equipment must not be undertaken unless the conditions of clause 157 of the WHS Reg are met.

The following work must be undertaken or supervised by a person who is authorised under the Home Building Act 1989 to do electrical wiring work.

• The disconnection or connection of low voltage AC supply wiring (fixed wiring) from/to an energised ICCP system located inside the Transformer Rectifier (TR) unit enclosure.
• Any work performed on appliances, wires, fittings or other apparatus that are connected to the low voltage AC side of an energised ICCP system or Transformer Rectifier Assisted Drainage (TRAD) system.

The following work is not required to be undertaken by a person who is authorised under the Home Building Act 1989 to do electrical wiring work where the work is on the ELV DC side of an energised or de-energised ICCP system or TRAD system.

• Work on the primary structure including coating work, operation of valves and other pipeline equipment.
• Testing at corrosion protection test points (including inside an enclosure where the test point is electrically insulated from the LV components according to AS/NZS 3000 Wiring Rules).
• Adjusting controls on an energised TR unit or TRAD where there is no risk of inadvertent or accidental contact with energised low voltage parts.
• Interference testing and other ICCP survey work.
• Drainage bonds where these have been de-energised.
• The plugging and unplugging of equipment from a power outlet to disconnect or isolate an ICCP system or remove it from a supply.
• Proving de-energised on extra low voltage parts where a dedicated isolator on the primary side or secondary side of the TR unit or TRAD (240V, 415V, or other supply voltage > ELV) is provided and where proving de-energised is done using a reliable means of indicating to a person when the ICCP system is energised.

Note: On permanently connected systems isolation facilities should be provided along with a reliable means of proving de-energised. This is considered to be ‘reasonably practicable’ to implement.

• Any work performed on de-energised ICCP systems including work on appliances, wires, fittings or other apparatus, including the extra low voltage parts of a transformer-rectifier unit (where risk controls consistent with AS/NZS 3000 Wiring Rules are in place to prevent inadvertent or accidental contact with parts operating above extra low voltage).

Competent persons working on the ELV side of ICCP systems are defined as those that have acquired through training, qualification or experience with the knowledge and skills to carry out the task. The necessary qualifications are set out in the NSW Electricity Supply (Corrosion Protection) Regulation 2020.