Electrical Safety Guide: Breaker vs Battery
Electrical work typically involves two different types of hazards, and selecting the correct protection must always be based on a documented risk assessment in accordance with SSG 4510. In many applications, both risks are present simultaneously and must be controlled using appropriate protective solutions. If there is any risk of contact with live parts, insulating (dielectric) protection is mandatory.
An arc flash is a sudden release of energy caused by an electrical fault, forming a conductive plasma arc that generates extreme heat, intense light, and pressure, capable of causing severe burns even without direct contact.
An electric shock occurs when electrical current passes through the body due to contact with a live conductor and may result in burns, muscle contractions, cardiac disruption, or fatal injury.
Where both arc flash and electric shock risks exist, thermal and dielectric protection shall be used together in accordance with SSG 4510.
Key principle
Arc flash protection = protection against thermal energy from electrical fault
Dielectric protection = protection against current passing through the body
Working with breakers
Use arc-rated protective equipment when working on or near energized equipment where there is a risk of an arc flash event and high incident energy release. Protection shall be selected based on calculated or estimated incident energy levels. Protection is required against:
- Extreme heat and flame
- Molten metal splashes
Typical applications
Circuit breakers and panels, switchgear and distribution boards, MCC cabinets and busbars, energized electrical cabinets.
Risk profile (breakers & switchgear)
- Equipment is energized and under load
- The primary hazard is a fault or short circuit
- This can result in an arc flash event with high incident energy
Arc flash energy is expressed in cal/cm2 (calories per square centimeter), representing thermal energy exposure to the skin. For example, ~1.2 cal/cm2 is sufficient to cause a second-degree burn.
Limitation
Arc flash gloves do not provide electrical insulation and must not be used where there is a risk of direct contact with live voltage.
Working with batteries
Use insulating (dielectric) gloves when working with or near energized parts where there is a risk of direct contact, particularly within limited approach distance. Glove class shall be selected according to system voltage and comply with applicable standards. Protection is required against:
- Electrical shock due to direct contact or insulation failure
Typical applications
Connecting/disconnecting batteries and battery packs, EV systems and charging infrastructure, live testing and troubleshooting, cables, terminals, and exposed conductors.
Risk profile (batteries & DC systems)
- Tasks involve direct interaction with terminals and conductors
- Systems may carry high voltage and current levels
- The primary hazard is current passing through the body
- Arc flash risk may also be present
Limitation
Insulating gloves without arc-rated inner protection do not protect against arc flash. If an arc flash risk is present, an arc-rated inner glove shall be used in combination with the dielectric glove to provide thermal protection.