Since the beginning of this year machine operators and manufacturers have been required to comply with the new Machine Safety Directive. Paul Considine of Wieland Electric explains how electrical contractors can help their customers gain the maximum benefits.
The new Machine Safety Directive came into force at the beginning of this year, but it isn’t entirely new to many contractors as there has been an extended transition period between the old and new Directives. During this time it has been acceptable to comply with either. A number of interested parties – including contractors, system designers, machine operators and manufacturers – have chosen to comply with the new Directive before they had to, and their experience shows there are a number of benefits to be gained.
To recap briefly, the new Directive was introduced to enhance safety. The reality is that the old Directive (enforced through EN 954-1) was too simple to handle the programmable electronics that are used in modern safety systems. In contrast the standards underlying the new Directive – EN ISO 13849-1 or EN (IEC) 62061 – were designed with modern technologies in mind. So the legislation has effectively caught up with the technology.
Consequently it makes sense to utilise these new technologies to gain the maximum benefits for the end user. EN ISO 13849-1, for instance, also facilitates the wider use of programmable safety relays. This, in turn, enables greater modularity to exploit the functionality of these newer processing technologies.
The end result of this is an opportunity for the end user to reduce costs – so the contractor that helps the end user do this is adding value to their own service (without compromising their own margins).
In the context of cost it’s worth pointing out that the cost of programmable safety relays, which have been perceived as expensive in the past, has fallen significantly in recent years. For example, as a general rule of thumb, a system using 3 to 4 stand-alone safety relays can be replaced by a programmable system for about the same cost. With more extensive systems the savings will be even greater.
Furthermore, there are additional benefits to using programmable safety relays, such as the ability to use a flexible logic editor to test the safety relays in the software before any installation work begins. This makes it quick and simple to spot potential problems and eliminate them at the design stage. As a result, much less time is spent in onsite testing, reconfiguration and re-testing, compared to dealing with stand-alone relays.
In our experience, when equipped with these tools, electrical engineers are more inclined to try out different solutions to arrive at the best solution, because they can save the original settings and quickly restore the system if something doesn’t work out.
There are also potential savings in installation times because while stand-alone relays require feedback loops and interconnecting terminals, programmable safety relays are wired back to a central I/O point. There are also fewer sub-systems overall, keeping the whole system simpler and less prone to faults.
Similarly, commissioning time is typically reduced as the software highlights any errors and any adjustments that are made during commissioning can be reversed through the software if they don’t work.
The software also incorporates a full reporting structure linked to the technical file, so that all information is recorded without manual intervention and reports can be generated very quickly. Feedback from users indicates this ease of reporting has helped them to understand their maintenance patterns in greater depth and utilise their resources more effectively as a result. Again, this is an area where value can be added to the project.
Beyond the design, installation and commissioning phases, there are benefits for ongoing maintenance of the systems. In terms of reactive maintenance, faults are easier and quicker to trace and fix, so that downtime is reduced and it is easier to comply with any Key Performance Indicators relating to ‘speed of fix’.
The result of all of these features is that contractors can help their customers take advantage of these new technologies to reduce their overheads and achieve a fast return on investment. So, in this respect, the new regulations are a very positive development for those contractors that seize the advantages on offer and apply them to the service they offer. And there is a lot of sense in teaming up with a company that has the knowledge to maximise these benefits.
