Electricity and Control November 2020

SENSORS + SWITCHES : PRODUCTS + SERVICES

Wastewater management for Tshwane Municipality

Bronkhorstspruit Sewage Works handles the wastewater of the municipality of Tshwane. The city’s wastewater network includes over 200 wastewater pumps that move liquid matter through pipelines to the sewage works. The submersible pumps operate 24/7/365 and are unmonitored. This presents a problem. Should a pump block, due to heavy volume or for some other reason, the pump mo- tor will overheat and burn out. Because the pumps are underground and unmonitored, the first sign that there is a fault is when the wastewater starts overflowing the manholes into streets: an expensive, unpleasant and un- healthy situation! Over previous years, many pumps have overheat- ed as a result of blockages in the impeller (rotating fan) caused by solid material such as diapers and other hard matter being taken up. The pump overheats because it is running dry and burn-out and failure are then inevitable. Levivi22 Engineering and Projects, contracted for the past four years to the Tshwane Municipality, is responsi- ble for projects, installation and maintenance of instru- mentation and specifically the maintenance of pumps that handle wastewater. Benoit Ntabala, Managing Director of Levivi22 ex- plained: “I have tried a lot of different pumps, some of them well-known brand names, without satisfactory re- sults. I then heard of Instrotech and met with Tinus Ludik, Account Sales Manager, who was keen to go out to the site to see our set-up first-hand, and to understand the problems we were encountering.” The solution was presented in Instrotech’s DPM4003 and DPM3001M temperature indicators (with low and high alarm relay outputs) which were recommended to measure and control the temperature of wastewater Senix ToughSonic ® Ultrasonic Sensors, available from Instrotech, are among the most versatile and flexible sensors on the market. They can be used in various ob- ject detection applications and can be customised for users’ specific needs. In the current situation of the coronavirus pandemic, for example, businesses around the globe are seeking solutions for social distancing requirements. In industry, applications may range from a beacon needed to signal if a vehicle has pulled up to the loading dock, or a method to indicate when a buffer space has been breached, or an alarm to sound if a pallet or obstacle is left in a controlled area. Senix has an appropriate solution for each instance. The state-of-the-art non-contact ultrasonic sensors can detect most materials: hard or soft, any colour or transparency, flat or curved. Compared to traditional proximity sensors, Senix ultrasonic sensors operate over longer distances and can be set up to limit object Customisable object detection systems

pumps. When the temperature exceeds 120°C, the pump is switched off. When the pump has cooled down to 60°C, it is switched on again. This process repeats until the necessary maintenance is done. The DPM4003 indicator has two NO/NC mechanical relay switches that makes this possible. There can be up to four relay switches for other applications. Tinus Ludik said, “At the end of July 2020, the DPM4003 temperature controller that we installed onto one of the pumps, tripped automatically before the pump could overheat, resulting in a direct saving of about R600 000. “This Instrotech solution definitely ensures fewer breakdowns and can save the pumps from overheating failure.” Tinus Ludik, Account Sales Manager, Instrotech, with Benoit Ntabala, MD Levivi22 Engineering, contractor to Tshwane Municipality. detection within a user-specified distance band or ‘window’. Senix Object Detection Systems can incorporate multi- ple sensors; the sensors easily connect with common auto- mation equipment and can control relays, alarms, displays, motor controllers and other functions. Applications range from simple on/off switches to relay connections, PLC in- puts and multi-sensor detection networks. They are cost effective and a number of user-adjustable features are built into the sensor’s software – SenixVIEW PC software – which enables the user to unlock the sensors’ versatility. Applications for Senix Object Detection Systems in- clude: automated packaging, materials handling, trans- portation safety signalling, as well as monitoring of social distancing. For more information contact Instrotech. Tel: +27 (0)10 595 1831 Email: sales@instrotech.co.za Visit: www.instrotech.co.za

For more information contact Instrotech. Tel: +27 (0)10 595 1831 Email: sales@instrotech.co.za, Visit: www.instrotech.co.za

22 Electricity + Control NOVEMBER 2020