Petroleum & Gas Inspectorate | Alert | No.125 V 1 | 16 January 2026

Risks due to inadequate electrical isolation at petroleum facilities

Summary

• A worker received an electric shock while conducting a routine task of replacing a communication module within a high-voltage battery cabinet at a petroleum facility.
• The preliminary investigation indicates possible contributing factors include working outside of a permit, an inadequate risk assessment to identify all potential hazards, insufficient isolation or separation between low and high-voltage equipment, and deficiencies in the design of the battery cabinets.
• The investigation is ongoing. Initial learnings are outlined below.

Issue Explained

• Instrumentation and electrical technicians were replacing a low-voltage communications module within a battery bank cabinet, which was part of the petroleum facility’s uninterruptible power supply (UPS).
• The batteries within the cabinet were wired in series to generate high voltage, and the cabinets had signage attached warning of high voltage.
• Initial information suggests the task of replacing a low voltage plug and play communication module was deemed low risk. Exposure to high voltage was not considered in the risk assessment.
• Upon replacing the communication module, workers identified a similar issue in another cabinet and progressed to investigate. This task to visually inspect the batteries was also deemed low risk.
• After completing the visual inspection, while closing the cabinet cover, the worker pushed a protruding cable into the compartment and received an electric shock to his hand, believed to be from an exposed battery terminal.
• The electric shock caused a minor burn to the worker’s hand. This incident had the potential to cause serious injury.
• The following contributing factors were identified:
  • Insulation: The identified low-risk work was inside a high voltage cabinet where battery terminals were not appropriately insulated nor isolated from their surroundings.
  • Cabinet design: The design of the cabinet, including the positioning of the module and associated cables. The positioning of the communication modules and management of associated cabling could have been better designed to minimise the risk.
  • Process and training: Potential gaps in risk assessment and training, exposing workers to increased risk of harm.

Figures 1 and 2: Battery bank cabinets in the control room (left) and the open cabinet showing the low and high voltage equipment (right).

Learnings

The investigation is ongoing, and preliminary learnings are:

• The elimination of hazards should always be prioritised over other controls. In this case, higher levels of isolation such as isolating the electrical supply should have been completed before work was carried out.
• Verification of safety management system processes should be regularly carried out to ensure safe systems of work are effectively managing risk and are fully utilised by workers.
• Workers must be appropriately trained in conducting and understanding risk assessments, the associated controls and their importance.
• Operators should adopt a "Safety in Design" (SiD) approach and implement appropriate isolation measures for high-voltage equipment or components.

References and further information

• Section 675(1)(e) of the Petroleum and Gas Act mandates a formal safety assessment covering all associated risks and control mechanisms.