61000-6-2 Electromagnetic Compatibility (EMC) for industrial machinery 1

[PaulBr]

Hello fellows:
How this standard, 61000-6-2 Electromagnetic Compatibility (EMC), is applied to industrial machinery. Words in standard are saying that it is applicable to "electrical and electronic apparatus".
In our case industrial machine consists of several devices (apparatuses), like VFDs, PLC, contactors, relays. Each of these devices bears CE mark. Declaration of conformity of each device states that this device is conforming to 61000-6-2 if installed per manufacturer instruction.
As machine builder, do we have obligation perform EMC test? Or statement in technical construction file that all electrical devices installed per manufacturer instruction and conform to 61000-6-2 giving us relief from actual testing.
Looking for opinions.

Thank you in advance

PaulBr

 

[Hoxton]

It is not LEGO!

A collection of individually EMC compliant components does not guarantee an EMC compliant assembly of those components.

It is not normally correct to take a set of components, to assemble these into a product and to assume that the product will then meet electromagnetic compatibility requirements without testing, since wiring will have been added along with other electrical and magnetic paths structure that will influence electromagnetic performance.
This wiring will provide potential aerial inputs and outputs for both emissions of radiations and conductions of interference into the apparatus and cannot be evaluated accurately without testing.

The EMC Directive allows for testing the worst case machine of each family (the manufacturer should document the rationale behind this choice within their Technical Documentation). This worst case test can then be used to represent the other variants of the same machine family. Manufacturers may use this approach to reduce test costs, but should also accept the increased risk it presents over testing every machine configuration (which is also an option).

 

[PaulBr]

Thank you for reply.
I am still not completely convinced. VFD manufacturer is stating in user manual that if its product connected according to the provided instructions it will meet EMC requirements. It implies that this manufacturer conducted testing, where input power was connected to drive, and output of drive connected to motor.
Is there distinction between "apparatus" and machine or definition of "apparatus" in CE standards?
Are you able to site any paragraphs from the standard that support your statement.

Best regards,

PaulBr

 

[Hoxton]

Ok I will come back to you

Are you in the uk?

 

[ScottyUK]

PualBR,

I suspect the difficulties - i.e. the bits which require engineering inout - are the places where the requirements of one component conflict with those of another. It would be fabulous if everything could be installed exactly as the manufacturer intended, every time, but I'm sure you agree that the imperfect world we live in doesn't always play to those rules.

For example, let's assume that the VFD manufacturer requires that all input and output connections are made with shielded cable as part of the EMC emissions control. Let's also assume that your client's specification requires that input power to the VFD is interrupted by a contactor* for emergency stop, thus interrupting the screen continuity. Is it possible to make this design pass the tests? Probably. Is it possible this design could fail the tests if you don't apply appropriate mitigation? Certainly.


* I know that many modern drives have a secure inhibit input for E-Stop functionality - it's just an example to demonstrate the point Hoxton was trying to make.

 

[Hoxton]

Scotty is correct, although as usual the regulations have to be read carefully.

Assuming that you are in the UK, then I attach the Guide as issued by BERR.

Please refer to para 3: each individual apparatus placed on the market must be accompanied by the appropriate information to ensure that when put into service, the apparatus complies with the essential requirements (of the Regulations).

Your VSD is Apparatus. So the manufacturer has given you a wiring diagram showing how to connect the VSD to other Apparatus in order for the VSD to comply with the EMC requirements. He may take this as his way of conforming with the Regulations, as above.

However your supplier is not the designer of the whole installation, and cannot possibly forsee what you may do as part of your design. As Scotty says, you may incorporate an Estop, you may incorporate an isolator between the VSD and the motor etc etc.

Secondly, please refer to the definition of Fixed Installation. You may consider that what you finally install is a fixed installation. If so then refer to para 2 of the guide.

If you consider that your product is Apparatus, then refer to para 3.

You will note the differences as regards testing and conformity.

Remember to document all this decision process in your Technical File. When it all goes wrong, that is the first thing they ask for! "What's that?" is not an acceptable answer......

Trust this all helps

 

[PaulBr]

Hoxton,

Thank you very much for the input and posted attachment. We will study it. A little bit of background:
We are original equipment manufacturer located in US. We are building large piece of machinery (consisting of 40 VFD motor circuits, PLC, etc.) which will go to France. These machines that we build are very custom. We are trying to determine if EMC testing is required. If required, would it need to be done for every machine in the future or just once, etc.

PaulBr

 

[Hoxton]

I would suggest seeking the advice of a consultant, preferably With experience of France.


There are some international ones like TUV, Google Emc consultants. It will be cheaper than getting it wrong!

 

[Hoxton]

I spoke with an acquaintance of mine. His advice was similar to mine, in that if this is your first project installed in the EU, then EMC is possibly the least of your concerns.

I consider that the most confusing area of all is the bit about apparatus designed solely for incorporation into a given fixed installation. These is all well and good for the EMC Directive – but let’s take a custom-engineered set for example that is purpose-built for an oil company. These tend to be very specialised. So, the manufacturer can then say “OK, I have custom-engineered this for XYZ Fixed Installation – I have done ABC to it in terms of sound engineering practice and it’s likely based on DEF plant that was EMC tested, so I don’t need to EMC test it”. Great. But he still needs to do all the tests and justifications for Machinery, LV, if it’s for outdoor use Noise and, from 22nd July 2019, RoHS, he needs to CE mark it and provide a DoC, so in fact the exemption is not altogether fantastically useful and could in fact mislead the manufacturer into thinking that he does not need to CE mark the product – however there are no such parallel clauses in the Machinery, LV or Noise Directive. RoHS has a Large Scale Fixed Installation exclusion, however!

 

[PaulBr]

The matter of fact this is not the first machine, but second one. Consultant was hired for the first machine. That machine was very similar but slightly smaller that current one we building.
His rationale do not have EMC test was that all devices have own DoC with EMC declarations in it. During commissioning and operation of the equipment no EMC immunity or emission problems have been observed. Therefore cost of EMC testing is not economically justified. It is shown in Technical Construction File.
For the second machine we are trying to compile technical file ourselves, using first machine as template. We started to look into standard to find something that support this statement.

PaulBr

 

[Hoxton]

Trying to look at this simplistically:

You talk about a machine. Never mind what this actually is.

Question: Is it shipped in one piece? Then it is Apparatus, as is freely transportable, within the EU, and someone is importing this machine into the EU.

If it is shipped broken down into parts (You have 40 VSD's so i can guess that it does not fit, asembled into an ISO container), and assembled on site, and not be intended to be moved. Then it is a Fixed Installation. CE marking UNDER THE EMC DIRECTIVE does not apply. (Note my capitals).

Assuming that it is a Fixed Installation, then from Annex 1 to DIRECTIVE 2014/30/EU:

2. Specific requirements for fixed installations
Installation and intended use of components
A fixed installation shall be installed applying good engineering practices and respecting the information on the intended use of its components, with a view to meeting the essential requirements set out in point 1.

So your view that you can compile the technical file for the second machine from the file for the first may be acceptable, as you should have met the essential requirements and used good engineering practices. Sorry, but I have to use the words “may” and “should”, as we do not have full details of what you are doing, just trying to help with the principles.

You still have to comply with the directive, however. This is not a derogation from the essential requirements, it is just an acceptance that you cannot product test the machine in the factory, as it not fully assembled until it is on site. So you may consider it prudent to EMC test it on site after commissioning...... or you may just rely on a justification in the technical file, as I think that most people would do.

If at some point in the future, the machine is moved to another site, and re assembled on that site, then the person who moved it would have to take the responsibility of compliance, under the directives applicable at that time.

 

[PaulBr]

Hoxton,

Thank you very much for taking second look and for the pointing to relevant standards.

Regards,

PaulBr

 

[Hoxton]

Please let us know how you get on. Good luck.