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View All Press Releases| Steute | 21 Jul 2011 |
IS A MISTRUST OF WIRELESS TECHNOLOGY RESTRICTING UK INDUSTRY?
In this article, .steute UK & Ireland’s general manager Steven Hill, looks at wireless control devices for use in safe and hazardous areas and asks if engineers still have concerns specifying wireless for on and offshore applications.
For engineers working in any sector of industry, and especially in potentially explosive and hazardous environments such as refineries and rigs, wireless control technology should be the default option. Yet it seems that in the UK, the very benefits that have led wireless control technology to be widely adopted in mainland Europe and beyond – safety, security, reliability – are often quoted as reasons not to adopt it!
So are these concerns reasonable i.e. can they be reasoned away?
Unfortunately history has played its part, especially as most people’s first experiences of wireless devices was the early Broadband router! When hardwired versions first appeared people immediately imagined how much better a wire-free system would be. Unfortunately, as often happens with new technologies, the first wireless routers offered good performance but were unreliable due to infrastructure. And of course it is human nature to transpose our experiences from the early days of wireless technology to offshore applications, creating or reinforcing the concern that wireless systems are not reliable enough to work in these environments.
Not a very positive legacy then!
So let’s consider the historic concerns against the latest technical advances in wireless control technology.
Is wireless stable?
Today’s wireless protocols are certainly very stable and extremely reliable. There are also many more to choose from and your selection should take account of the environment and the application. For example, the 868MHz licence-free wireless protocol can be used in normal safe areas and ATEX certified zones (Gas 1, 2 and Dust 21, 22); and thanks to a growing range of wireless explosion-proof switches and sensors (certified to II 2G Ex ib II T6 & II 2D Ex ibD 21 T80°C) there is no longer the need to use the special tools, cables or glands associated with hardwired position switches.
Is wireless reliable?
For some engineers, the ongoing issue of batteries being required to power the transmission data protocol is a barrier when considering wireless products in industrial environments. This is especially problematic when switchgear is installed in difficult and/or remote locations.
This problem has now been solved by companies such as .steute that have developed battery-less position switches or pushbutton devices that generate their own power on demand. This enables the devices to transmit radio signals back to the receiver over distances from a minimum of 30m (internally) to a maximum of 300m (externally). Reliability is further enhanced because the signal is transmitted quickly, within 80ms, so there are no underlying issues regarding interference from external sources.
Certainly benefits such as faster installation, much easier engineering and, consequently, reduced capital spending, should be attractive enough to encourage engineers to adopt wireless to solve challenging control problems, where traditional wired technology is both difficult and expensive.
Using safety showers on oil rigs as an example, pushbuttons can be used to activate showers which, at the point of actuation, can trigger wireless limit switches that transmit a signal to the medical support team to announce that they are in use and that medical attention may be required. Without wireless control for this application, you would need to assemble a small army to sort things out. First, you need to employ a team of engineers to survey and prepare the area for Ex-certified cable to be routed, an expensive business even before you count the cost of the expensive cable; second, a team of electrical engineers will be needed to lay the cable and terminate it at either end. All this before your signal can even been transmitted! As well as being a cost effective solution, mechanical engineers will find installation of a wireless pushbutton extremely simple and as they can be mounted to almost any surface using just two screws.
This example easily demonstrates where wireless control technology excels compared to conventional hardwired systems. Not only would wireless have saved the cost of the Ex-certified cable, it would also have eliminated the need for a team of electrical engineers!
What about signal strength?
A question engineers often ask when considering wireless transmission is: “How do I know the strength of a signal after it has been transmitted from a device?”
Apparently, the response from some companies has been worryingly vague: “If it is over a short distance then it should work!”
Fortunately most engineers would know that such a response is unacceptable as there is no proven test to show that the signal generated is just on the minimum receiver signal strength level required.
However, to reassure engineers that the signal generated will be received by the receiver module, .steute has introduced a meter that can be used to measure the signal strength RSSI (radio signal strength indicator) transmitted from the switching transmitting device. Metering is offered as part of the standard service during installation and, if required, signal strength meters are also available to purchase. In addition, if you are now convinced that wireless control will benefit your application, they can even arrange a site survey to determine whether your particular installation would require a high-gain antenna or a number of strategically positioned repeaters to re-direct the transmission signal to the receiver module.
…….and hazardous areas?
You may now be convinced that wireless systems are more than capable of performing, but what about the potential problems that could arise in hazardous areas? The answer is that for most applications the combination of Ex and wireless shouldn’t pose a problem to those wanting to use both technologies in potentially explosion and hazardous environments.
Summary
A few years ago, embracing wireless technology required almost an act of faith. Today wireless devices have advanced to a degree that makes them more than just a replacement for traditional technology, and those that have installed wireless-based switches and sensors are now reaping the rewards compared to the conventional hardwired approach.
If you are interested but not sure that there is a wireless device to suit your application, a .steute catalogue covering the extensive range of wireless products is available. It also includes case studies showing how more and more engineers are embracing wireless technology to help improve productivity and reduce costs in a variety of applications. A link to a ZVEI document offering support on integrating wireless products is also available for download on the .steute website.
For further information call .steute UK & Ireland on +44 (0)1684 310430, email infouk@steute.com or visit www.steute.co.uk.
Ends
1095 words
File: Wireless Article - Offshore
For further information contact:
Steven Hill, steute UK & Ireland
Acorn Business Centre, Roberts End, Hanley Swan, Malvern, Worcs WR8 0DN
Phone +44 (0)1684 310430 Fax +44 (0)560 3424018
Email: s.hill@steute.com Web: www.steute.co.uk
For press information contact:
Simon Cantillion, Cantillion King Advertising
16 The Cornhill, Stroud, Gloucestershire, GL5 2JT
Tel: +44 (0)1453 755551 Fax: +44 (0)1453 751525
E-mail: simon@cka.co.uk Web: www.cka.co.uk
