Steps For Preventive Maintenance For Transformers

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Welcome To Royal Transformers
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Steps For Preventive Maintenance For Transformers
For a successfully working transformer, the need
for proper installation, loading, and maintenance
is just as imperative as is the viability of its
design and manufacture. Transformer manufacturers
in India are aware of this when they build
transformers. However, the need for preventive
maintenance of transformers is still important
for the long lifespan of a working transformer.
The tasks performed under preventive maintenance
is not exactly the same as those that are done as
part of major overhaul repairs. However, some of
these tasks may be the same in terms of how it is
done.
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Preventive Maintenance of Transformers
The general principles behind preventive
maintenance are similar in the case of almost all
transformers. However, for detailed explanations
for specific transformers of a particular
manufacturer, consulting the user manual provided
by the manufacturer may be necessary. Protective
maintenance is of three types preventive
maintenance that involves scheduling and testing
on a regular basis predictive maintenance that
involves additional testing and corrective
maintenance which involves repairing or restoring
the transformer to its original standards.
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1. Insulation Under preventive maintenance, the
   insulation of the transformer should be
   thoroughly checked. Mineral and paper insulation
   is constantly affected by moisture, air, heat and
   other elements that are corrosive to its
   functioning.
2. Inspection New transformers, when purchased,
   should be inspected thoroughly before
   installation to check if they are damaged in any
   way during the shipping process. This inspection
   can save a lot of time, energy and money in the
   present by rejecting damaged goods rather than do
   continued repairs on the transformers which will
   only increase the maintenance cost.
3. Testing After the transformer has been
   installed, a number of tests should be conducted
   on it to see if it is working well.

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• The insulation resistance of the new transformer
  should be tested and recorded for comparison
  purposes in the future when the transformer may
  require any repairs.
• The AC dielectric test is conducted immediately
  after the insulation resistance is conducted.
  This is an important one because the dielectric
  voltage is much higher than the normal voltage
  and induces high stress on the transformer.
• The transformer turns ratio is tested to
  determine the number of turns of the primary coil
  in comparison to the number of turns in the
  secondary coil. The accepted values of this ratio
  should not be more than 0.5 of the calculated
  value.
• The insulation power factor test measures the
  watt loss experienced during the working of the
  transformer.

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• 4. Cleaning During an inspection or otherwise,
  if any dirt is found accumulating on the
  transformer coils or insulator, then it should be
  immediately removed. The coils can be cleaned by
  the use of a vacuum cleaner, a blower or
  compressed air that is clean and free of dirt and
  impurities. The remaining surfaces like the
  insulation should be brushed or wiped down with a
  dry cloth regularly. The use of liquid cleaners
  is highly inadvisable as these may contain
  solvents that can corrode the insulating
  material.
• 5. Routine Maintenance For the purpose of
  routine maintenance, there are a few tests that
  must be conducted.
• The insulation resistance test of winding to
  winding and winding to earth.
• Dielectric absorption test of winding to winding
  and winding to earth for ten minutes.
• The turns ratio test that is similar to the test
  mentioned earlier.
• AC overpotential test for high and low voltages
  of winding to earth.
• Insulation PF test of winding to winding and
  winding to earth. The values of this should be
  less than 3.
• While drying out a transformer before it is
  installed or after a major shut down, either
  external heat, internal heat or both external and
  internal heat may have to be used but only after
  any free moisture should is blown off or wiped
  away.

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Contact Us
Address             Royal Electricals
Plot No.1405, Phase-IV, GIDC
Estate, Vithal
Udyognagar-388121, Dist. Anand. Contact Person
 Mr. P.A.Patel Tel.No                (02692)
236047/9825022670 Fax No               (02692)
236048/236236 E-Mail               
response_at_royaltransformers.com
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