The new Machine Safety Directive, which came into force earlier this year, opens the doors for many safety and cost saving benefits. Paul Considine of Wieland Electric explains how to exploit them
Following an extended transition period between the old and new Machine Safety Directives, compliance with the new directive is now mandatory. And while getting to grips with new regulations is often distracting (or worse) these regulations can offer some real benefits that should be seized with both hands.
Clearly safety is the paramount concern, and one of the key benefits of the new directive is that it enables safety to be achieved more efficiently and cost effectively – when approached in the right way. This is because the old EN 954-1 standard had effectively fallen behind technological advances. Fundamentally it was too simple to handle the programmable electronics that are used in modern safety systems.
However, the standards underlying the new directive (EN ISO 13849-1 or EN (IEC) 62061) have been designed to complement modern technologies and make it easier to deploy them in safety systems.
Programmable safety relays
A good example of this is programmable safety relays – the use of which is facilitated by the new directive, thus enabling greater modularity to exploit the functionality of these newer processing technologies.
Programmable safety relays also create opportunities for cost savings at every stage of the process – from initial system design through to ongoing maintenance. At the design stage, for instance, a flexible logic editor allows the safety relays to be tested in the software before installation begins. In this way, any potential problems can be spotted and designed out before work begins. Consequently, much less time is spent in on-site testing, reconfiguration and re-testing, compared to dealing with stand alone relays.
We have also found that having this benefit of ‘foresight’ encourages engineers to try out different solutions, potentially coming up with a better solution, as the only implication of getting it wrong is the need to undo the error in the software.
Installation work is also simplified, compared to working with stand alone relays, as programmable safety relays are wired back to a central I/O point with no need for feedback loops and interconnecting terminals. There are also potential time savings on commissioning, as any errors are clearly highlighted in the software and, as with the design process, any errors made during commissioning are easily reversed through the software.
Once the system is up and running this enhanced functionality extends to tracing faults and fixing them when something goes wrong, speeding up the process compared to manual fault tracing and reducing down-time. Furthermore, once the fault has been identified it can often be rectified by in-house maintenance staff rather than calling on specialist engineers at hourly rates that reflect their expertise.
In terms of managing the system, 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 that this ease of reporting has helped them to understand their maintenance patterns in greater depth and to utilise their resources more effectively as a result.
It’s also worth mentioning that programmable safety relays, once considered an expensive option, are now very affordable, so there is no longer a price penalty in making use of them. As a general rule of thumb, a system using three to four stand alone safety relays can be replaced by a programmable system for about the same cost. With more extensive systems, using greater numbers of relays, it will typically cost less to use programmable safety relays than stand alone relays, introducing even more cost savings to the equation.
When all of these features are considered it’s clear that the new Machine Safety Directive has the potential to be positively beneficial for machine operators. Design and installation of new or refurbished systems is quicker, often with a better solution, and the ongoing cost of ownership is reduced – all adding up to an attractive return on investment. And there is a lot of sense in teaming up with a company that has the knowledge to ensure you maximise those benefits.
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