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Warning systems

Warning systems

Are you struggling to find guidance on beacons and sounders? In the view of Simon Adams of Werma UK, it's all a matter of 'good practice'.

The Machinery Directive 2006/42/EC urges machine builders to undertake a thorough safety analysis of the systems that monitor and control the operation of their machines. While the DOs and DON'Ts are well defined in the Directive for many aspects of machine safety, guidelines for the provision of visual and audible warning indicators are more vague; there is 'guidance' but little in the way of 'you must...'. It is more a case of applying 'good practice and common sense'.

Visible and audible warning lights on a machine or workstation generally indicate a change in status and may also warn of an error in machine operation or a malfunction. In any event, staff working in the vicinity of equipment displaying warning lights need to be aware of the change in machine status indicated by them, and take such steps as their operating procedures require. But how can visible and audible warning systems contribute towards ensuring that 'good practice' is achieved in the workplace?

A starting point is the risk assessment. Once the risks have been identified, the next stage is to reduce them to an acceptable level. The general rules are: if there's a risk, eliminate it; if you can't eliminate it, guard it; and if you can't guard it, warn about it.

One of the most dangerous phases of any machine operation is start-up. When you press the 'go' button, the last thing you want it to do is to start the machine. It must first initiate a procedure to check for safety Interlocks and self-test routines to ensure it is in an appropriate mode for start-up, with guards closed and so on. It might be common practice to monitor danger zones with light curtains and similar technology, but these systems can be overridden by operators. Unless you can see the danger zone is clear, can you be sure it is safe to start?

The Directive tells us that "machinery must not start up unexpectedly". It's difficult to define what "unexpectedly" means in this context, so let's turn it around, making sure that anyone in the vicinity of a machine will expect an audible and/or visual warning as part of its start-up sequence.

Now, we're all familiar with the concept of traffic lights and will intuitively understand that a red light is something that requires a certain defined response. So it is with visible and audible warning systems. The characteristics of the signal, the brightness of the beacon and loudness of the sounder need to be appropriate to the machine and its environment. And, just as importantly, you need to make sure the paperwork's done and the meaning of the signals is included in the operating manuals.

Werma is a leading European manufacturer of visible and audible warning systems and accessories, including signal towers, beacons, sirens, buzzers and horns in a wide range of colours, light pictures and sound emission levels. The company can provide a solution to virtually any machine status and safety monitoring problem. In addition to classical beacons, sounders, stack lights and traffic lights which will indicate machine status loudly and clearly to the workforce on the shopfloor the introduction of a unique wireless monitoring accessory - WIN - will transmit machine and workplace status information to remote parts of the company thus ensuring that the right people are informed about a machine status change and can take the necessary corrective action to ensure that the safety of the operation is maintained.  

WIN is usually mounted on the standard range of KS71/70 signal lights and transmits the relevant signal light and machine status change to a receiver unit plugged into a local pc which can be made available to the company's personnel in the form of a control panel overview of shopfloor activity, runtime and productivity reports which monitor duration and frequency of machine error and downtime and the time taken to rectify errors.

In 2012, Werma joined forces with five other manufacturers of safety related equipment (Pilz, Festo, Troax, and Fortress Interlocks) to form the Machinery Safety Alliance, the main purpose of which is to provide expert and impartial advice on machine safety related issues via regular seminars and the Internet.

In 2013 Werma UK moved into new premises in Wellingborough, Northants, form where a full sales and technical service is offered, backed up by extensive stocks and a next day delivery service. Comprehensive details of the range available can be found on Werma's website and e-shop.
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