Guide to Certifications in Power Supplies
29th October 2025Share This Post
Share This Post
When it comes to specifying a power supply, the right certification can make or break a project. Engineers often focus on wattage, efficiency, and thermal performance, but compliance and safety marks are what keep products legal and safe to operate.
At Relec Electronics, we often get asked why certification matters so much, and which ones to look for. The truth is that certifications are not just red tape, they’re your introduction to market access, long-term reliability, and peace of mind when your design goes live.
Let’s break it down.
Table of Contents
Why Certifications Matter
The purpose of a power supply is to convert one voltage (AC or DC) into another voltage (AC or DC), providing the necessary power for a system’s electronics. That conversion process introduces potential risks including electrical isolation issues, thermal stress, and electromagnetic interference. Certifications exist to prove that these challenges have been properly addressed and independently verified.
A certified power supply should not just tick a regulatory box. It also:
- Ensures product safety for end users
- Confirms compliance with regional legislation
- Reduces liability for manufacturers and integrators
- Simplifies approval for export and system integration
As a distributor, Relec works closely with a range of manufacturers to ensure every unit we supply carries the right documentation, testing data, and approvals for your end application.
Key Certifications Explained
Below are the most common power supply certifications, along with what they really mean in practice.
For products sold in the European Economic Area and UK, CE and UKCA marks confirm compliance with directives such as the Low Voltage Directive and EMC Directive. They cover aspects like:
- Electrical safety (shock protection, insulation, clearances)
- EMC emissions and immunity
- Environmental design and labelling
Most of our range including Cosel TUNS and Cotek AEK-3000 series come with CE and UKCA certified as standard, allowing easy integration into industrial and transport systems across Europe and the UK.
✨Tip: CE and UKCA can be self-declared by the manufacturer but always check the accompanying Declaration of Conformity and referenced standards.
In the United States and Canada, power supplies must meet standards from UL (Underwriters Laboratories) or CSA Group.
- UL 62368-1 covers IT and industrial electronics
- UL 60601-1 applies to medical power supplies
- UL 508 applies to industrial control equipment
Our Cincon CFM and CQB series DC-DC converters, for example, hold UL 62368-1 approvals, ensuring safe operation within industrial and embedded computing environments.
Remember the distinction between:
UL Listed
Certified for standalone use (e.g., desktop adapters)
UL Recognised
Certified as a component within a larger system
Application-Specific Standards
Application
Typical Certification
Example Product
Defence
MIL-STD-810G
Cincon CQB150-300S Series – Rugged DC-DC converters for defence and harsh environment systems
Railway / Transport
EN 50155, EN 45545-2
Vox Power VCCR300 series – ruggedised power modules for rolling stock
Efficiency & Environmental Certifications
While safety is mandatory, efficiency standards are increasingly in focus:
- ErP / Ecodesign Directive (EU): Sets minimum efficiency levels for standby and active modes.
- 80 Plus Programme: Common for IT and data-centre supplies.
- DoE Level VI (USA): Defines external PSU efficiency requirements.
Relec’s EDAC Power range are excellent examples, achieving high efficiency and meet global ErP and DoE standards.
Engineer’s Certification Checklist
When specifying a power supply, ask:
- Which markets will the system be sold in?
CE/UKCA for Europe, UL/CSA for North America, PSE for Japan, CCC for China. - What is the end application?
Medical, transport, industrial or IT each have unique standards. - Is the supply a component or finished product?
Choose UL Recognised components for integration, UL Listed for standalone use. - Does the certificate include EMC testing?
Emission and immunity compliance ensures system stability. - Has the product been tested to the latest standard revision?
Standards evolve; check version numbers and date of issue.
Why Power Supply Certifications Matter to Relec Customers
Our engineering customers don’t just want a compliant power supply, they want assurance that it’s the right certification for their project. A medical OEM may require reinforced isolation; a railway integrator may need EN 50155 approval. Relec helps identify those needs early and match them with appropriate, certified solutions.
Beyond supplying the hardware, we provide access to:
- CE/UL certificates and Declaration of Conformity documents
- Safety reports and test summaries
- Reference PCBs and thermal application notes (particularly from Cosel’s TUNS and TEPS series)
This technical transparency shortens development cycles, simplifies documentation, and helps you maintain compliance right through to production.
Conclusion
Certifications in power supplies are far more than fine print, they include the foundation of reliable, legally compliant design. From CE and UKCA through to UL, EN 62368-1 and EN 50155, these marks ensure that your system performs safely in the field, passes audits, and earns customer confidence.
Relec Electronics partners with trusted manufacturers to offer fully certified, technically verified solutions for industrial, medical, and transport sectors.
If you’d like help checking the compliance of your next design, get in touch with our technical team, we’ll guide you from request, to refinement, to certified results.
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