Page 6 - Energize January 2021
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        New transformer monitoring

        technology gives speedy results

        Information from WearCheck

        WearCheck recently invested several million rand in four brand new laboratory instruments for its
        transformer division laboratories in Johannesburg, Durban and Cape Town.

                 anaging director Neil Robinson says the company’s investment in the  He explains further that the new PCB
                 equipment has relieved some of the current sample volume pressure and  instrument determines the presence of
                 reduced turnaround times in line with customers’ expectations, ensuring that  PCB in electrical equipment containing
       Mtransformer oil samples are processed and analysed even faster than before.   insulating oil, which must be tested at
           WearCheck’s transformer division now has an additional two new high-speed gas  least once and after every maintenance
        chromatographs (GCs) in the Joburg and Durban laboratories, and an additional new PCB  event to determine the PCB level.
        (polychlorinated biphenyl) chromatograph, as well as an additional new HPLC (high  According to the latest version of SANS
        performance liquid chromatography) in both the Cape Town and Durban labs.   290:2016, the current maximum allowed
           “Getting the analytical test results and diagnoses to our customers as fast as possible is  PCB level in oil is 50 ppm (parts per
        a priority for us,” says Robinson, “and our investment in the new instruments has ensured  million or mg/kg). If the PCB level exceeds
        that our transformer sample testing capacity is more than doubled. Our transformer division  this limit, the oil must be drained and
        also recently moved to a new, larger laboratory in Westville, where we offer a wide range of  disposed of in an approved manner. As
        specialist transformer monitoring techniques.”                           PCB molecules are highly toxic, this is an
           The new Perkin Elmer GCs – designed and manufactured in The Netherlands –  important test in transformer maintenance
        each have a carousel that can hold 120 prepared samples and standards. Added to the  and management for both health and
        80-sample capacity of the existing GCs in the Durban laboratory, with more samples being  environmental purposes.
        processed at any one time, the sample turnaround time has been significantly reduced.  “The additional HPLC,” continues Nel,
        The same instrument was bought for the Johannesburg lab, boosting their existing GCs.   “separates mixtures of compounds in
           “One of the great advantages of the new GCs is that they can be pre-loaded with  transformer oil to identify and quantify the
        samples before a weekend, and they will continue operating for 48 hours. Our older models  individual furanic compound
        require reloading every 24 hours,” says transformer division manager, Gert Nel.   concentrations of the oil. The results
           “The primary function of the GC is to perform dissolved gas analysis (DGA) – a highly  enable our diagnosticians to predict the
        effective preventive maintenance tool which has formed part of WearCheck’s condition  remaining useful life of the paper
        monitoring programmes for more than ten years,” says Nel.                insulation of the transformer with high
                                                                                 accuracy, giving an exceptionally good
                                                                                 indication of the remaining useful life of
                                                                                 the transformer itself.”
                                                                                    Nel observes that new instruments
                                                                                 have already reduced sample processing
                                                                                 time. “Our transformer customers in
                                                                                 various business sectors such as mining,
                                                                                 power generation, transport,
                                                                                 manufacturing, industrial and marine
                                                                                 maintenance are receiving their results at
                                                                                 high speed, which enables them to make
                                                                                 critical maintenance-related decisions in
                                                                                 good time and reduce the risk of
                                                                                 unplanned transformer failure,” he says. n

                                                                                 Contact details:
        Senior analytical chemist, Lynette Pillay, feeds samples into the new HPLC (high performance  W:
        liquid chromatography) machine at WearCheck’s transformer laboratory in Durban.  T: +27 (31) 700-5460

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