ATG Zone 1/21 Water Disinfection System case study

atg UV Technologies, located in Pemberton near Wigan, had a requirement to build two high specification control panels for the disinfection of water using UV radiation in a hazardous area.


Extronics worked closely with atg to design and build the control systems to meet with the requirements of the ATEX directive and to operate in harsh and hazardous environments.

Incorporating bespoke technology from atg which was housed in flameproof Ex d enclosures manufactured from epoxy coated aluminium display windows were integrated into the design to provide visibility of crucial control information including many innovative features such as automatic start up and shut down as well as multiple UV lamp monitoring and process interlocks.

To optimise oatg water disinfectionverall performance and functionality Extronics provided surface mounted push buttons and cabling was radically simplified by the integration of close coupled Exe junction boxes with Ex d cable transits between the enclosures.

The added advantage of this type of configuration was the overall reduction in the physical size and weight of the system.

A 24VDC supply mounted within the Ex d enclosures protected by circuit breakers powered the system and the PCB’s, were connected to two electronic ballasts connected to an array of four UV lamps which were the source of Electromagnetic Radiation (EMR) to disinfect the water.


To maintain the operational tolerance of the UV lamps a galvanic isolator provided an intrinsically safe power supply to a UV intensity probe located inside the irradiation chamber, current sensors were also employed on the ballasts to the lamp terminals in conjunction with an earth leakage relay to detect any faults within the cabling.

Extronics’ wide range of experience and in depth knowledge of the industry for which the system was destined, combined with a high level of Ex expertise, resulted in Extronics engineering a bespoke duty-stand-by package for the disinfection of potable drinking water.

The system provided the end user with clean and safe drinking water for offshore crews worldwide.