• • • CABLE & CONNECTORS • • •
level 1 and 64 engineers have taken around 6 courses at level 2).
As well as purchasing Fluke ii910 units to scan overhead power lines in the distribution network, the company took on a range of other rugged hand-held standard maintenance tools from Fluke. These include 49 Fluke 1736 three-phase power loggers alongside nearly 1000 Fluke 376 AC/DC clampmeters, 470 Fluke 1507 insulation testers and 600 1ACII non-contact voltage detectors.
Move towards value-based
maintenance Mohammed Yehia, distribution engineering specialist, who has more than 21 years of experience in the maintenance development department, explains: “Our focus changed around six years ago to distribution of electricity only, not transmission or generation, for four regions in the Kingdom – east, south, central and west. “After benchmark trials in utility companies in Australia, USA, Italy and Dubai, we decided to move away from condition based maintenance (CBM) towards doing more predictive maintenance. Initially, we started using thermal cameras with metering for overhead line networks mainly in the south sector (we also carried out partial discharge testing in underground cable networks) and we found that our KPIs, including sustainable development, improved a lot in just one year.”
In developing its maintenance strategy, SEC found that the move from CBM to value-based maintenance (VBM) in 2018-19 boosted the reliability of its networks. Official statistics from the Saudi Arabia Water & Electricity Regulatory Authority show the advances that have been made in terms of reducing outages.
The System Average Interruption Duration Index (SAIDI) is used as a reliability index by electric power utilities. In the Jazan area alone, where SEC poured investment into improving the overhead line network, the average unplanned outage length went from 406.66 minutes in 2011 to 123.46 by 2022. “This is just one area,” points out Zakaria, who also has over 20 years’ experience at SEC and is the Distribution Engineering Specialist. “You can look anywhere and see big improvements since we moved to VBM, with savings of around 20% on our maintenance costs. This includes manpower and spare parts but also the number of shutdowns. “Before, we used to carry out maintenance for the customers even if it wasn’t required. We used to inspect our networks every six months whereas for the past three years we have inspected just once a year. This is very important because now we only do maintenance when it’s needed – that’s the whole strategy.
“Our engineers test for hot spots in the weakest part of the network, usually the connections, and compare temperatures between the phases, calling for maintenance only if they detect a certain percentage of difference.”
Reliability is the key Zakaria continues: “Reliability is the key issue when supplying power. We are a utility company, and we focus on two things – bills and outages. Customers pay the company to supply power with no outages, which is why minimising disruption to supply is the most important focus for us. “When we are talking about heat, we are talking about lost power and we are losing money. More important, though, is that we can make our
customers happy by cutting the number of outages. That’s the main thing. When we followed a CBM approach we used to get a lot of customers with complaints about faults. Now, there are very few cases.”
Having begun its study into using the Fluke ii910 cameras for corona partial discharge detection, SEC calculates it is saving four times the cost of any hardware through improved efficiencies. To boost efficiency still further, SEC is looking to carry out remote maintenance inspections, using patrolling cameras and drones where possible for transmission lines maintenance. Zakaria says: “Thermal imaging is not a new technique, in our company it’s been used for more than 25 years, but we have invested in the most advanced cameras and trained our technicians to get the best out of the equipment while switching from periodic maintenance to condition based maintenance. “We wanted to improve our reliability, enhance
our service to customers and cut our maintenance costs. The Fluke equipment has played a major role in helping us achieve those goals, which is why we have been using it since 2012 and are looking to buy more.” Mohammed adds: “Value based maintenance is now our umbrella approach for all types of maintenance so we can create the most effective duration cycles for inspection. For example, for meters inspections are every 10 years, for overhead lines every year and substations every year. “We’re now looking at monitoring partial discharge at our substations online 24-hours-a-day and I have many other power projects that will benefit from the VBM approach and our move towards automation.”
18 ELECTRICAL ENGINEERING • APRIL 2023
electricalengineeringmagazine.co.uk
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