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Safety during interventions on very low voltage circuits with high energy*

1. Context and specific risks

Electrical installations at very low voltage (VLV, ≤ 60 V) are often perceived as safe for people. However, when these circuits are capable of delivering high energy or current, the risks become significant:

  • Electric arc in case of short circuit or mishandling,

  • Thermal burns due to local heating or molten metal splashes,

  • Material damage to equipment and fire risks.

These dangers are even more present in systems powered by high capacity batteries (e.g. Li-ion or lead), motors or power converters, capable of delivering several hundred amperes even at a voltage below 60 V.

2. Personal protective equipment (PPE)

Before any intervention, it is essential to wear appropriate PPE for the nature of the electrical and mechanical risk:

  • Insulating gloves suitable for low voltage and cut-resistant, to prevent direct contact and splashes.

  • Protective visor or transparent face shield, to protect against radiation and splashes from a possible arc.

  • Fitted and non-synthetic clothing, preferably flame-retardant cotton, to prevent the fabric from melting onto the skin.

  • Strict prohibition of jewellery, watches, chains, rings and any conductive metal objects.

The aim is to minimise exposed conductive surfaces and reduce the risk of injury in case of fault.

3. Organisation and work environment

A safe environment is an essential factor for prevention:

  • Clear work area, clean and well-lit, to avoid accidental short circuits by contact with metal objects.

  • Adequate ventilation, especially in the presence of batteries that may emit gases (hydrogen, volatile electrolytes, etc.).

  • Suitable extinguisher in immediate proximity, in accordance with local instructions:

    • Class ABC extinguisher for general solid, liquid or electrical fires,

    • CO₂ extinguisher for sensitive electrical and electronic fires.

Each operator must know the location and use of these emergency means.

4. Lockout and safety procedure

Lockout is an essential step before any intervention on an electrical circuit, even at very low voltage. It is based on the principle of the 5 safety steps:

  1. Disconnect the power supply (physical disconnection from the energy source).

  2. Lock/tag out the disconnecting devices to prevent any re-energisation.

  3. Identify and label clearly the locked-out area and conductors.

  4. Verify the absence of voltage using an appropriate measuring device.

  5. Ground and short-circuit, if necessary, circuits that can accumulate energy (e.g. capacitors, long cables).

This approach ensures that no one can accidentally restore power during the intervention.

5. Conclusion

Working on very low voltage but high energy circuits requires the same rigour as on high voltage systems. Adhering to safety rules, wearing appropriate PPE, and systematic lockout are the keys to preventing serious accidents such as burns, electric arcs, or fires.

Safety is never a constraint, but an essential professional reflex for managing electrical risks.


*: The technical information presented in this article is provided for guidance only. It does not replace the official manuals of manufacturers. Before any installation, handling or use, please consult the product documentation and follow the safety instructions. The Torque.works site cannot be held responsible for inappropriate use or incorrect interpretation of the information provided.