BS EN IEC 61204-3:2018

What is BS EN IEC 61204‑3 – low voltage about?

BS EN IEC 61204 is a European standard that discusses the electromagnetic compatibility (EMC) of low-voltage switch-mode power supplies.

BS EN IEC 61204‑3 specifies the electromagnetic compatibility (EMC) 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 power supply (PSU) units as defined in BS EN IEC 61204‑3. It covers PSU units for use in or with IT equipment normally covered by IEC 60950-1 and/or IEC 62368-1. It also covers DC power and distribution equipment and DC/DC converters.

Note: BS EN IEC 61204‑3 does not apply to

• Motor-generator sets,
• Uninterruptible power supplies (UPS) to IEC 62040-1
• PSUs covered by IEC 61558-1 (i.e., power supply units incorporating safety isolating transformers providing SELV or PELV output(s) in accordance with IEC 60364-4-41) and PSUs for use with household and other consumer products, except those covered by IEC 60065 and IEC 60950-1 and/or IEC 62368-1
• Transformers covered by IEC 61558-1
• Step-down converters covered by IEC 60146-1-1
• PSUs and converters intended for DC supplied bulb lamps, halogen lamps or LED lamps covered by CISPR 15

Who is BS EN IEC 61204‑3 – low voltage for?

BS EN IEC 61204‑3 on electromagnetic compatibility applies to:

• Manufacturer of low voltage power supply machines
• Electrical engineers
• Quality check personnel

Why should you use BS EN IEC 61204‑3 – 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.

EMC testing helps minimize the possibility that radiated or conducted emissions produced by your device will interfere with other electronic products in its vicinity.

BS EN IEC 61204‑3 provides the requirements for the manufacturer of the PSU has a responsibility to provide guidance relating to the EMC performance, application, intended environment and installation guidelines for the product.

BS EN IEC 61204‑3 navigates you through the test conditions where all the tests specified in BS EN IEC 61204‑3 are type tests only. A PSU device is deemed to fulfil the requirements specified in BS EN IEC 61204‑3 if it complies with the defined functional and performance requirements using the test methods specified in BS EN IEC 61204‑3. Precautions are taken against the EUT (equipment under test) becoming dangerous or unsafe as a result of the immunity tests specified in BS EN IEC 61204‑3.

By using BS EN IEC 61204‑3, you can ensure the safety and precautions of Electromagnetic compatibility (EMC) for low voltage switch-mode power supplies.

What’s changed since the last update?

BS EN IEC 61204‑3:2018 supersedes BS EN 61204‑3:2001, which is withdrawn. It includes:

• The title has been changed by deleting the wording "DC output-" from the title and adding "switch mode" in the title
• Changes in the scope: 1.1.1 Equipment covered by BS EN IEC 61204‑3 and update of the normative references to the latest editions or dated references
• Change of wording or/and notes regarding the requirements of CENELEC Guide 24 and IEC Guide 107 and correction of typographical errors
• Revision of the emission limits to align with the latest editions of the applicable normative references
• Revision of the immunity requirements to align with the latest editions of the applicable normative references