Electricity and Control November 2023

PLANT MAINTENANCE, TEST + MEASUREMENT

Power supply considerations for wireless monitoring systems Wireless remote monitoring technology provides a cost-effective method for plant and asset managers to monitor and manage important system data across their sites, particularly over large areas. However, wireless system performance is often limited by power availability and many site managers are unsure how to select a system that runs efficiently with limited power supply and still transmits all key data. Ian Loudon, International Sales Manager at Omniflex, sets out the key power supply considerations for wireless systems and how to select the right system for the job.

W ireless telemetry systems are essential for mon itoring and control applications in various key industrial sectors, including mining, utilities, petrochemical, nuclear and oil and gas. In many of these applications, laying cables for a traditional wired network is not feasible because of strict regulations and planning permissions required. Furthermore, the cost of cabling can often be prohibitive. Therefore, in many cases, wireless telemetry systems represent the only way to retrieve and manage critical data from the field safely and efficiently. Power considerations Generally, the further we want to send data, the more pow er we need to do it. For licence-free radio, which operates at 868 MHz in the UK and South Africa and 900 MHz in Australia, installations generally need to be under 500 mW. However, licence band radio systems, which are more ex pensive to operate due to ongoing licensing costs, operate effectively at up to 25 W. Therefore, high power installations are better suited to using licence band radio. Power can impact system availability and is usually a high priority in terms of systems specification. Often, wireless systems are deployed in remote areas without access to mains power, so alternative supplies must be explored. This adds another layer of complexity for site managers unsure of what they need to get systems up and running.

In the age of Industry 4.0 and the widespread deployment of remote installations, it is often assumed that battery powered systems will more than suffice as many modern battery systems can run for five years or more. However, this can get costly in terms of battery replacements if implemented on a site with, say, 100 units or more. Many plant-wide applications may use more than 1 000 wireless units across a large area. Replacing 1 000 industrial batteries at one time would represent a significant outlay, so it is important that site managers relying on battery-powered systems plan ahead and devise a maintenance plan to replace them on time, before the system degrades. Using solar-powered units generally allows site manag ers to sidestep the issue of costly battery replacements, improving cost efficiency and reducing maintenance re quirements. However, these units are only effective in are as with sufficient sunlight to keep the unit powered up and operational. With these various factors to be considered, it is impor tant to engage a reliable wireless partner who can assess the system requirements and operational restrictions, and recommend the most suitable and cost-effective system to serve the client’s needs. A knowledgeable wireless partner Omniflex’s wireless telemetry modules allow users to config ure inputs as either analogue or digital inputs and outputs,

Wireless telemetry systems are widely used for monitoring and control applications in key industrial sectors such as mining and utilities where assets are dispersed over a large area.

22 Electricity + Control NOVEMBER 2023