What is IEC 60479?

IEC 60479 is an international standard that provides guidelines for electrical safety in low voltage installations. It covers the effects of electric shocks on the human body, as well as methods to prevent and minimize these risks. This technical article aims to provide an in-depth understanding of IEC 60479, its scope, key concepts, and implications for electrical safety.

Scope of IEC 60479

IEC 60479 applies to electrical installations with operating voltages up to 1000 volts AC and 1500 volts DC. It considers the effects of electric current passing through the human body and focuses on two main areas: the physiological effects of electric shock and the limits of exposure to electric current. The standard primarily targets electrical installers, engineers, and safety professionals involved in the design, installation, and maintenance of low voltage systems.

Physiological Effects of Electric Shock

Electric shock can have severe consequences on the human body. IEC 60479 classifies the effects into four zones, each associated with a specific range of electric current passing through the body. Zone 1 refers to currents below the perception threshold, where the individual may not even feel a shock. Zone 2 involves currents above the perception threshold but below the let-go threshold, causing muscle contraction and an inability to release the source of electricity. Zone 3 encompasses currents above the let-go threshold, potentially leading to fatal or harmful involuntary muscular reactions. Lastly, zone 4 consists of currents that can cause ventricular fibrillation, posing a risk of cardiac arrest.

Implications for Electrical Safety

Compliance with IEC 60479 is crucial for maintaining electrical safety. Adhering to this standard helps prevent electric shock incidents and guarantees the protection of individuals working with low voltage installations. It requires proper grounding, insulation, and protective measures to minimize exposure to electric currents. Additionally, IEC 60479 emphasizes the importance of risk assessment and provides guidelines for determining safe levels of current based on factors such as duration of exposure and body resistance.