IEC 62368-3:2017

Overview

IEC 62368-3:2017 is an international standard published by the International Electrotechnical Commission (IEC) focusing on the safety aspects of DC power transfer through communication cables and ports. It is part of the IEC 62368 series that addresses audio/video, information, and communication technology equipment safety. This part specifically applies to equipment designed to supply and receive operating power through communication cables or ports, covering power transfer circuits from power sourcing equipment (PSE) to powered devices (PD) using DC voltages classified as ES1, ES2, or in specific cases, ES3.

The standard emphasizes the safe design and implementation of DC power delivery over communication interfaces such as USB cables, where the cable may be used solely for power transfer without communication signals. IEC 62368-3:2017 is designed to be used in conjunction with IEC 62368-1:2014, which provides the foundational safety requirements for audio/video, information, and communication technology equipment.

Key Topics

1. Scope and Applicability

• Covers DC power transfer through communication cables or ports connecting Power Sourcing Equipment (PSE) to Powered Devices (PD).
• Applies to voltages within safety levels ES1, ES2, and occasionally ES3, with ES1 and ES2 generally aligning with non-hazardous voltage definitions used in other standards (e.g., SELV, PELV).
• Communication cables are defined broadly to include industry standard connectors that permit DC power transfer, irrespective of communication functionality.

2. Safety Requirements

• Electrical-caused injury safeguards for both PSE and PD.
• Prevention of electrical-caused fires due to DC power transfer circuits.
• Specific safeguards addressing single fault conditions in power sourcing equipment.
• Design criteria for overcurrent, overvoltage, and insulation protection.
• Requirements for interfacing DC power transfer with building wiring and other equipment.

3. Remote Power Feeding (RFT)

• Defines power transfer using remote feeding technologies such as RFT-C and RFT-V.
• Covers limitations on electrical energy, current, and voltage to ensure user safety and equipment protection.
• Classification of RFT power sources and related fire protection measures.
• Specifies installation instructions and safeguards to mitigate risks related to remote power feeding.

4. Integration with IEC 62368-1

• Cross-references and harmonization with IEC 62368-1:2014 to maintain consistency in safety engineering.
• Applies relevant clauses from IEC 62368-1 as far as reasonable when designing DC power transfer circuits.
• Provides normative and informative annexes to explain rationale, operational considerations, and safety principles.

Applications

IEC 62368-3:2017 is essential for manufacturers, designers, and testing laboratories working on:

• DC power delivery over USB cables used for device recharging or power supply without communication.
• Equipment providing power through Ethernet or other communication cables implementing Power over Ethernet (PoE) or similar remote feeding solutions.
• Audio/Video and ICT devices requiring safe DC power transfer across communication ports.
• Ensuring compliance in products such as docking stations, portable devices, network equipment, and communication terminals.
• Developing new product safety standards by technical committees for equipment that transfers DC power through communication interfaces to align with global safety requirements.

Related Standards

• IEC 62368-1:2014 – The primary standard for the safety of audio/video, information, and communication technology equipment, providing foundational safety principles referenced throughout IEC 62368-3.
• IEC Guide 104 – Provides guidance on group safety publications and harmonization across IEC standards.
• Other relevant IEC Electrotechnical Standards covering electrical safety, wiring rules, and product certifications may complement IEC 62368-3 compliance activities.

Conclusion

IEC 62368-3:2017 plays a critical role in ensuring the safe transfer of DC power across communication cables and ports, addressing modern needs in audio/video and communications technology. Understanding and implementing this standard helps mitigate risks of electrical injury and fire hazards while enabling innovative power delivery solutions in ICT equipment. Compliance with this standard, alongside IEC 62368-1, supports global market access and product reliability in a growing connected device ecosystem.

Keywords: IEC 62368-3, DC power transfer, communication cables, power sourcing equipment, powered devices, electrical safety standard, USB power delivery, remote power feeding, IEC 62368-1, ICT equipment safety, Power over Ethernet, product safety standard, audio/video equipment, electrical injury prevention, fire protection requirements.