IEC 60364-4-44:2024

Overview

IEC 60364-4-44:2024 - Part 4-44 of the IEC 60364 series - sets requirements for the safety of low-voltage electrical installations against voltage disturbances and electromagnetic disturbances. This third edition (2024) is a technical revision that cancels and replaces the 2007 second edition and subsequent amendments. The document addresses protection measures inside electrical installations (not the public energy distribution or generation systems), including risk assessment, overvoltage control and electromagnetic interference (EMI) mitigation.

Key Topics

• Scope & structure: Updated in line with ISO/IEC Directives, Part 2:2021; terms, definitions and symbols regrouped (Subclause 440.3).
• Power-frequency overvoltages (Clause 442): Guidance on temporary overvoltages originating from earth faults and conductor faults, and calculation limits for tolerable stress voltages.
• Transient overvoltages and SPDs (Clause 443): Risk assessment methods, classification of rated impulse voltages (overvoltage categories) and provisions for Surge Protective Devices (SPDs). Clause 443 has been amended to better introduce DC SPDs and clarify wording.
• Electromagnetic influences (Clause 444): Practical measures to mitigate EMI, including sources of interference, earthing and equipotential bonding, segregation of circuits, cable management systems, protective devices and handling of services entering buildings.
• Undervoltage protection (Clause 445): Requirements and considerations for preventing operational issues due to undervoltage.
• Informative annexes: Examples of risk level calculations for SPD application and guidance for overhead line overvoltage control.

Practical Applications

IEC 60364-4-44:2024 is used to:

• Define installation rules to limit damage from lightning, switching transients and conducted disturbances.
• Specify when and how to apply Surge Protective Devices (SPDs) including considerations for DC systems.
• Design earthing and equipotential bonding networks to reduce EMI and ensure safety.
• Plan cable segregation and cable management to limit interference between power and signal circuits.
• Conduct risk assessments to justify protective measures and select appropriate overvoltage categories and protective devices.

Who Uses This Standard

• Electrical designers and consulting engineers
• Installation contractors and site electricians
• Facility managers and building services engineers
• Surge protection and earthing product manufacturers
• Regulatory bodies and inspectors concerned with low-voltage safety and EMI mitigation

Related Standards

• IEC 60364-1 (general principles and scope of the 60364 series)
• ISO/IEC Directives, Part 2:2021 (document structure and editorial rules)

Keywords: IEC 60364-4-44:2024, low-voltage electrical installations, protection against voltage disturbances, electromagnetic disturbances, SPDs, earthing, equipotential bonding, EMI mitigation, transient overvoltages.