BS EN IEC 61204-7:2018

What is BS EN IEC 61204‑7 – low voltage about? 

BS EN IEC 61204 is a series of European standards that discusses the various functionalities of low voltage switch-mode power supplies. 

BS EN IEC 61204‑7 specifies the safety requirements for switch mode power supply (SMPS) units supplied by source voltages up to 1 000 V AC or 1 500 V DC providing AC and/or DC output(s), except inverter output(s) establishing AC mains. 

This product standard covers both stand-alone and component SMPS as defined in BS EN IEC 61204‑7. DC power and distribution equipment which provides, distributes, monitors, and controls isolated secondary circuit power to other equipment typically used in information and communication technology equipment installations. 

Note: BS EN IEC 61204‑7 does not include: 

• Functional safety aspects as covered by for example IEC 61508 (all parts) 
• Reliability and risk considerations (e.g., related to power loss) 
• Information and communication technology equipment other than SMPS to such apparatus 
• Electrical equipment and systems for railways applications and electric vehicles 
• Motor-generator sets, uninterruptible power supplies (UPS), direct plug-in power units 
• Power supplies according to IEC 61558 (all parts) covering linear power supply units incorporating safety isolating transformers providing SELV or PELV output(s) in accordance with IEC 60364-4-41 and SMPS for use with household and other consumer products 
• Transformers covered by IEC 61558-1 
• Step-down converters covered by IEC 60146-1-1 
• SMPS and converters for use with or in products covered by IEC 61347-2-2 
• AC or DC mains supply distribution equipment which is part of the building wiring system and not an integral part of the equipment used in DC power and distribution equipment, batteries, the design or installation of DC power and distribution conductors and other building installation wiring (not covered by Annex AC) 

Who is BS EN IEC 61204‑7 – low voltage for? 

BS EN IEC 61204‑7 on electromagnetic compatibility applies to: 

• Manufacturer of low voltage power supply machines 
• Electrical engineers 
• Quality testing 
• Suppliers and distributors of low voltage power supply 

Why should you use BS EN IEC 61204‑7 – low voltage? 

Low voltage is used in electric power transmission and distribution, and electrical safety codes define "low voltage" circuits that are exempt from the protection required at higher voltages. Using low voltage electrical devices lowers costs and increases safety. Low voltage electrical supply also improves energy efficiency. Most sources of renewable energy, including solar, hydro, and wind all provide low direct current power. 

BS EN IEC 61204‑7 specifies the requirements to reduce the probability of fire, electric shock, thermal, energy and mechanical hazards, except functional safety as defined in IEC 61508. The objective of BS EN IEC 61204‑7 is to establish common terminology and a basis for the safety requirements of products that contain power electronic converters across several IEC technical committees. 

What’s changed since the last update? 

BS EN IEC 61204‑7:2018 supersedes BS EN 61204‑7:2006, which is withdrawn on 16 March 2021. It includes: 

• Use of IEC 62477-1 as a reference document, instead of IEC 60950-1 
• Modification of the title by deleting the wording “DC output- “and adding “switch mode”.