Page 17 - Industrial Technology Extra 7th September 2020

of energy every year. A primary requirement is
therefore to make a transformer as efficient as
possible to reduce both the financial loss and the
emissions of greenhouse gases, and other
pollutants, when generating the extra energy
required to make up for the power lost in
transmission.
The efficiency of a transformer, needs to be
carefully verified before shipment to the customer;
the terms and conditions of the sale of a transformer
typically specify financial penalties running to tens
of thousands of Euros if it fails to operate as
efficiently as specified by the manufacturer.

Precision analysis requirements
The measurement of a transformer’s efficiency,
according to the IEC60076-1 industry standard,
requires an instrument capable of measuring
voltage, current, phase and power (W) over a range
of power factors from 1 down to 0.01.
SEA entrusts these critical transformer power
measurements to the Yokogawa WT5000, the
world’s most accurate precision power analyzer,
which offers an AC power measurement accuracy of
±0.03% at 50 / 60 Hz and provides performance
guarantees from 1% to 130% of the selected performance over many years of use – this is a very
voltage and current ranges. High accuracy important reason for us to choose the WT5000.”
measurements at very low power factors SEA’s customers therefore benefit from the
particularly requires a power analyzer to possess highest possible specified operating efficiency,
very low uncertainty for its internal phase shift. This which in turn gives the manufacturer a competitive
along with all other influences are fully specified for edge in the market, since claimed efficiency is one
the WT5000, which makes it ideal for the of the most important factors affecting the
measurement of transformer losses under no-load transformer buyer’s choice of product.
conditions. Renato Franco of SEA concludes: “For us, it is
Renato Franco, Testing Manager at SEA, says: vital to deliver a product that matches its high
“When buying an instrument intended for use over design specifications. By using the proven accuracy
a period of many years, measurement stability is as and stability of the WT5000 to both specify our
important as accuracy.” Continuing he says: transformers and to check their individual
“Evidence from accredited calibration shows that performance, we are confident that our customers
the instrument not only provides us with the are really getting what they are paying for.”
accuracy we need, but also maintains its www.yokogawa.com

September 2020 • INDUSTRIAL TECHNOLOGY EXTRA • p17