Recently, an existing customer requested additional units of equipment we had previously designed for them, this time shipping to Europe. Enter CE and IEC requirements to gain expertise in!
With our customer expecting equipment ‘identical’ to what was previously manufactured, we needed to ensure compliance with slightly different codes while maintaining the design & elegance of the existing machines.
IEC Requirements
I’m not going to labor through IEC requirements, that’s a mostly straightforward read of code. IEC 60204 is the primary safety of electrical machinery code but make sure you review anything applicable to your product HERE. One quick comment (and one you can find in many places) is that designing to NFPA 79 as you already do, and then adapting to the differences of IEC is a reasonable approach that shouldn’t result in surprises.
CE Requirements
Our review of directives was a good learning experience, and this WEBSITE was an excellent resource. You will be best served by completing your review before getting too far into design, parts ordering, or construction of your equipment. An ounce of prevention… As we were re-building existing designs, we ordered a few long-lead items to protect the schedule, but resisted the urge to go too far until we dove into comparing our design to the directives to make sure the ultimate result was successful.
Electro-Mechanical Machinery
For our electro-mechanical machinery, we found several directives to incorporate. The two directives with the most content for us are Electromagnetic Compatibility (EMC, 2014/30/EU) and Machinery (MD, 2006/42/EC), but aspects of Energy-Related Products (ERP, 219/125/EC), Low Voltage (LVD, 2014/35/EU), WEEE II (2012/19/EU), RoHS (2011/65/EU) were also incorporated. This is what was true for us, but be sure to review all of the directives as you embark on your journey. You may find ATEX or others to be relevant to your equipment design.
The Machinery Directive
Here’s a good place to start. I hope you don’t find much that will surprise you here, but there is a large amount of content and it’s there for a reason. Above all else, we need to make sure our machines are safe. If you don’t already utilize them, be prepared to work through ISO 12100, 13849-1, and 13849-2 to perform a risk assessment, quantify risks, and ensure you are selecting protective devices of appropriate Performance Level. With our existing designs, there were no surprises. The equipment had already been designed with safety in mind and no changes resulted from this.
Other Directives
Of course, we only familiarized ourselves with the directives that apply to our industry and application. For a complete breakdown of all of the directives that may apply to you, I’ll refer you back to this WEBSITE. You may find a bit here. Particularly in the electronic sub-components you are sourcing. As appropriate, look for CE, REACH, and RoHS indication on what you are sourcing. It needs to be there. Understand who the importer is for your equipment and what registration is needed as well.
Electromagnetic Compatibility
Now we’re cooking. (Sounds like that cooking may be using induction.) This is where your diligence can really pay off. Intertek reports a 50% failure rate on initial EMC testing of electronic products. Ouch. I can happily report that we passed testing on both machines. We did utilize a well-known 3rd party to help in our compliance process, TÜV SÜD, but there was a bit of last-minute adjusting to make it happen.
On the first machine, an integrated laser engraver (integrated without modification), was identified as being susceptible to a high voltage line-ground surge (>1.2 kV). This was a bit surprising as the laser is a CE certified unit from a major manufacturer. Nonetheless, accommodation needed to be made, and we installed surge protection devices on line & neutral, protecting it. With this modification, our machine could now pass the gamut of emission & vulnerability tests that TÜV SÜD subjected it to.
On the second machine, we also ran into an issue. This one we’ll have to take full credit for. A combination of an overly sensitive analog sensor and wishful thinking that we could keep the incoming power cable bundled with other cables entering the electrical enclosure proved problematic. That analog senser proved to be susceptible to several different immunity tests including ones that introduced noise into the incoming power line as well as electromagnetic field immunity tests.
We started with a re-route of the incoming power cable. We had already physically located AC power in one section of the cabinet, DC in another, and potentially noisy VFDs & torque drives in another, so the implementation wasn’t too tough. We re-routed the power cable on the machine differently and brought it in to the far corner of the electrical enclosure to reduce potential for noise on the incoming power line from being transmitted to other components. , but it still proved troublesome during some of the electromagnetic field immunity tests using bulk current injection.
Knowing we had other sensors of similar function on the machine that were passing the same tests, we ran a couple of trials to prove out a different sensor in this location. Have your parts and tools handy, you don’t necessarily have a lot of time when a 3rd party is visiting your site for a defined time slot to perform testing! If not solved that day, we would have been in a position of waiting until they could make it back (and paying for the additional visit). Putting our engineering skills to use with a tight deadline definitely led to a sense of accomplishment. However, I do not recommend this as the best approach to teambuilding due to the aforementioned consequence of potential delay with rescheduling and cost.
Best Practices
The onsite testing and adjustments are parts of our journey that are easy to point to as clear ‘broke-fix’ situations, but in reality, much more went into passing the electromagnetic compatibility (EMC) testing. I cannot prove what we didn’t test, but here are things we did ahead of time and will always do again:
- Sweat the details! The engineering & part selection upfront certainly didn’t hurt in passing EMC testing. There is some time involved which does incur cost and potentially impacts schedule, but you’ll reap the rewards later in the project. Our upfront engineering & time costs were reasonable especially compared to what the cost of fixes later on could have been.
- Clean power supplies (essentially no cost)
- Cleaner VFDs (minimal cost)
- A couple more shielded cables than original design (minimal cost)
- Power line filter on incoming power line & before noisy components (minimal cost)
- Pay attention to grounding & cable shield grounding (easy)
- Pay attention to cabinet layout- separate AC from DC and separate potentially noisy components (somewhat easy, free space helps)
- Pay attention to cable routing- separate AC from DC, separate cables that potentially have noise, and cross at 90° angles when needed (somewhat easy, this applies both in electrical cabinet and on the machine)
- Review all subcomponents for CE certification (easy)
- Pay attention to manufacturer installation instructions (grounding, spacing, etc.) (easy)
- Purchase Reach & RoHS registered wire (easy)
- If possible, schedule a little extra time for EMC testing and be ready to play a few games.
- Have clamp on ferrites rated at different frequencies & ferrite rings of appropriate sizes on hand.
- Know your machine. A 3rd party helping to certify will know the code & test methodologies, but they only have so much time to learn your equipment. Help them along. Be ready to answer questions. Critically evaluate what they are looking at, telling you, etc. and don’t be afraid to question why they are looking at something or why they haven’t looked at something. In a nutshell, help them with the current job and learn all you can from them to proactively apply to your future projects.
At the end of it all, you get to re-review the requirements for labeling and declaration, make up a nice, shiny nameplate proudly displaying your company’s name and CE (and other required information) for your machine, complete the declaration of conformity, and don’t forget to hold a lessons learned meeting. Lastly, we highly recommend celebrating with a nice company lunch!