Software launch and advice on EMC testing

29 April 2010

Laidler Associates have launched the latest version of its Risk Management Software System, now called mCom.The latest version has been fully updated to cover the requirements of the new Machinery Directive, 2006/42/EC, compliance with which became mandatory from 29th December 2009. Other enhancements include an option for users to decide whether they work to ISO EN 13849-1 or EN954-1 for the safety of machinery, and an on-disk copy of the Health and Safety Executive's new PUWER Approved Code of

The software covers PUWER 98 requirements and CE marking for machines and is an ideal complement to the advice and support available from Laidler's expert consultants. For those who wish tofind out more about this versatile package, a free demonstration version is available for download from www.laidlersoftware.com
Don’t be caught out by EMC!
Many machine builders are under the impression that all they have todo to ensure that their products meet the requirements of the EMC Directive is to use components that carry CE marking. This is, however, a dangerous route to take, says Paul Laidler of Laidler Associates, one of the UK's leading safety and compliance consultants.
It's not hard to see that a single item of equipment - let's say it's a variable speed drive, just as an example - could well meet the limits set down in the Directive, but this provides no guaranteeat all that, if you put two, three or more of them in a control panel, the overall emission levels will still be satisfactory. This problem has been neatly summed up with the "equation" CE + CE ? CE (CE plus CE doesn't equal CE).
Testing is not mandatory, but how can the EMC performance of a machine be predicted unless testing is carried out? Since there's noreliable way of calculating or modeling the EMC performance of a machine, the position of Laidler Associates is that the 'only' certain route to compliance is testing. And Laidler Associates is not alone in this view.
Asked for clarification of this issue, the Health & Safety Executive(HSE) provided a written response that includes the following statement:
"Section 6 of the Health & Safety at Work Act (HSW) places a duty on manufacturers to carry out or arrange for the carrying out of such testing and examination as may be necessary to ensure that the article is so designed and constructed that it will, as far as is reasonably practicable, be safe and without risks to health. In the context of EMC, in most applications it is the electromagnetic immunity of equipment that is of interest in relation to Section 6 of the HSW. If it is reasonably practicable to carry out testing for immunity to electromagnetic disturbances, the HSW requires this to be carried out".
There are many examples of what happens when this advice is ignored, such as the "Mystery of the Windermere Triangle" which was recently widely reported in the news media.
Drivers in Windermere's busiest shopping area found that their wireless key fobs would "mysteriously" cease to operate the locking mechanisms of their cars. After this "mystery" had endured for some time, OFCOM, one of the bodies charged with enforcing the EMC Directive in the UK, carried out investigations. These revealed that the signals from the key fobs were being jammed by emissions from wireless ordering system in a nearby café!
This example is trivial and even slightly amusing, but that isn't always the case. Consider what might happen if a machine were to start up unexpectedly because it was susceptible to interference from say, a mobile telephone or an arc welder being used in the vicinity. Unfortunately, these are not imaginary issues - problems of this type have occurred, and have led to serious consequences.
All of this demonstrates that there is no shortcut to achieving compliance with the EMC Directive. In order, not only to meet legislative requirements but also to ensure safety, machines must be properly tested.
While the testing itself can be complicated, machine builders can take comfort in knowing that help is at hand. Laidler Associates is always ready to offer expert advice on EMC issues, and can also arrange for testing to be carried out on behalf of its clients. For machine builders there is, after all, an easy way to avoid being caught out by EMC!