Lubezine Volume 8 * NOVEMBER 2013 - JANUARY 2014 | Page 20

COVER

FEATURE
OIL ANALYSIS

How a cost-efficient oil
analysis programme can
prolong transformer life
mined for replacement. Some of the checks
are relatively simple: the operation of the
gas relays, the operation of the on-load tapchanger, checks on oil leaks, and so on.
However, breakdown of one of the most crucial elements, the oil / paper insulating system,
can only reliably be detected by routine oil
analysis. By measuring certain physical and
chemical properties of oil, in addition to the
concentrations of certain dissolved gases, a
number of problem conditions associated
with either the oil or the transformer can be
determined.

Moisture Content

I

t is well known
that regular
oil analysis is
extremely useful
in monitoring the
condition of engines,
drive trains, hydraulics, turbines and
many other types of
By Neil Robinson
oil-lubricated equipMr.Neil Robinson is
ment. The same can
Managing Director of
be said for transWearCheck
former oils, which are
used to insulate many transformers and other
electrical distribution equipment. The analysis of transformer oils not only provides information about the oil, but enables the detection
of other potential problems, including contact
arcing, ageing insulating paper and other
latent faults. It is also an indispensable part of a
cost-efficient electrical maintenance program.
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Failure risk
Transformer maintenance has evolved
over the past 20 years, from a necessary
item of expenditure to a strategic tool in the
management of electrical transmission and
distribution networks. Extreme reliability is
demanded of electric power distribution, and
even though the failure risk of a transformer
and other oil-filled electrical equipment is
small, when failures do occur, they inevitably
lead to high repair costs, long downtime and
very real safety risks. Moreover, transformers
are too expensive to replace regularly and
must be properly maintained to maximise
their life exp X