Complex assemblies: a grey area for machine safety
Machine safety expert Paul Laidler, who is business director (machinery) at TÜV SÜD in the UK, ponders the tricky question of whether entire production lines need to be CE-marked.
One question I get asked on a regular basis is whether a series of machines, such as a production line, needs CE marking as a machine in its own right when the individual machines making up the line have all been CE-marked.
As with anything where there is an element of interpretation, it’s not always clear what the way forward is. The Machinery Directive, includes the following definition:
Assemblies of machinery or partly completed machinery which, in order to achieve the same end, are arranged and controlled so that they function as an integral whole.
The key part of the definition is arranged and controlled. What we often see is that while the neighbouring machines may “talk” to each other – so that the output from one acts as the input for the second – there aren’t always overriding controls such as a global safety circuit. In this case, you probably don’t need to CE mark the overall line. Once you start having controls that affect the entire installation, you are entering the realm of the complex assembly and you will probably need to look at CE marking the line.
If you are going to CE mark a line made up of CE-marked machines, your Technical File will include all the declarations for the individual machines. For the assessment, you’ll need to focus on the interface between the machines and the global controls.
If your line is a mixture of current and new machines, then it becomes more complicated, depending on the age of the older machines. Machines currently in use may pre-date CE marking and if these are included in a new line, you are going to have to assess the line more closely than perhaps you will if it is all new machines.
You also might not have (or be able to get hold of) relevant documentation for the older machines which can leave potential gaps in your technical file, making the process more difficult to finalise satisfactorily.
One thing to remember, no matter which CE Directives you’re dealing with, it’s usually the case that CE+CE ≠ CE.