When does a change invalidate my CE Marking?

2010/10/13

This post is by Steve Hayes, EMC & Safety Managing Director, TRaC

A question we often have posed to us at TRaC is: “I’ve modified my equipment, does it need a retest?”

The answer as you may guess isn’t simple, since it depends on the changes themselves. CE Marking is a ‘self-declaration’ process and hence the manufacturer decides if its product complies with the appropriate directive or not – not the test house. That said, the test house can offer advice and this is something we get actively involved in.

Simple queries along the lines of ‘I’ve changed the colour of the paint’ are easy to understand since this doesn’t affect the EMC or safety of a product (unless it’s a child’s toy and an assessment of the paint is required).

However, things get a lot more complicated when obsolescence in components or sub-assemblies requires a more fundamental review – how do you know that a product meets the same EMC standard when the power supply is changed for another without testing?

One way of dealing with the issues is to have a scoring matrix – a score of 0 may apply to a change of paint colour, whilst 5 might apply to major sub-assembly changes. When a change is made, it is scored and when the number hits 5, a retest is required.

Even if a retest is required, it might not be that a full retest is needed. Taking the PSU as the example and assuming that it is approved in its own right, there would be little need to retest the immunity of the product since each of the bits of the system have been previously approved.

The emissions however would need to be reviewed and probably retested, but these costs are relatively small, compared with retesting the whole thing again.

Applying some thought to the changes and the possible factors that will be affected is a sure way to reduce the ongoing compliance burden and ensure that the product’s compliance is maintained.

Previous Certification & Test entries:

* What’s the difference between Bluetooth and ZigBee?

* Do you really know what’s involved with safety testing?

* So what’s new in RF connected medical devices?

* New immunity standard for IT equipment, but is it any good?

* ENERGY STAR programme gets tough

* 5 ways to fail Low Voltage Directive (LVD) testing

* If WEEE’s in, what’s out?

* CE Declaration of Conformity… is it worth the paper it’s written on?

* Seeing is believing

* Withdrawing presumption of compliance

* Four Things You Need to Know About Seismic Testing