Page 6 - Energize January 2021

COVER STORY

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

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