Transformator 500kVA (SKI)

Dok.ref:
UOS-90-56097

Kommentar:  

Cleaning with a cloth and warm water will in most cases be
sufficient, unless the transformer is exposed to a corrosive
atmosphere, in which case chemicals or soap can be used. It is
important to remove dust, dirt, salt, grease, etc. from the liners.

Frequency of maintenance depends on the environment and what is
considered necessary. Cleaning on once a year will normally ensure
safe and continuous operation.

Filling of oil on hermetically sealed transformers should
preferably be done by the manufacturers, who have equipment for vacuum
filling. This is especially important if the transformer has a gas
guard, in which case the relay may give an unwanted alarm signal due
to the fact that air may remain in the transformer. However, if the
repair needs to be done elsewhere, follow the instructions below.
Filling of oil on hermetically sealed transformers is done through the
filling pipe. HV bushings are also filled with oil, if these are not
of the plug type. Oil filling must be carried out at 20-30 ° C.

Lift and move the transformer using lifting equipment attached to a
lifting sleeve or to a lifting point under the trolley. The lifting
equipment must be mounted on the same side as the filling pipe or the
gas guard so that the air, which is trapped under the lid, can escape.

Replace the 1 "plug with" gland "and tighten well.
If oil has been drained from the transformer so that the windings have
been in contact with air, the transformer must be filled in a vacuum
or left for at least 24 hours before applying voltage or performing a
voltage test. If the insulation or windings are changed, these must be
dried for a minimum of 24 hours at 90 - 100 ° C before the transformer
is filled with oil.

If the complete transformer is placed in an oven for drying, it is
recommended that it last for 48 hours at 90 - 100 ° C. If the peak
temperature is below 60 ° C when the transformer is opened, or if
there is a leak in the transformer, the tank will draw in air due to vacuum.

The transformer is filled at 35 - 40 ° C at the factory.

Dok.ref:
UOS-90-56097

Kommentar:
The silica gel has the ability to absorb moisture from the air, and
will change colour as follows: 

Orange: Completely dry.

Pale orange: Partly saturated with water.

Transparent: Fully saturated with water.

The silica gel can be removed and dried at a temperature of max.
130 ºC for the blue type and 130 ºC-160 ºC for the orange type. Silica
gel, blue type, can absorb about 20% of its weight of water, while
orange type can absorb 40% of its weight of water. For
"breathers" with oil sump, check that there is oil in the
oil sump, so that the silica gel does not come in direct contact with
the atmosphere.

Frequency of maintenance depends on the environment and what is
considered necessary. Cleaning on once a year will normally ensure
safe and continuous operation.

Filling of oil on hermetically sealed transformers should
preferably be done by the manufacturers, who have equipment for vacuum
filling. This is especially important if the transformer has a gas
guard, in which case the relay may give an unwanted alarm signal due
to the fact that air may remain in the transformer. However, if the
repair needs to be done elsewhere, follow the instructions below.
Filling of oil on hermetically sealed transformers is done through the
filling pipe. HV bushings are also filled with oil, if these are not
of the plug type. Oil filling must be carried out at 20-30 ° C.

Lift and move the transformer using lifting equipment attached to a
lifting sleeve or to a lifting point under the trolley. The lifting
equipment must be mounted on the same side as the filling pipe or the
gas guard so that the air, which is trapped under the lid, can escape.

Replace the 1 "plug with" gland "and tighten well.
If oil has been drained from the transformer so that the windings have
been in contact with air, the transformer must be filled in a vacuum
or left for at least 24 hours before applying voltage or performing a
voltage test. If the insulation or windings are changed, these must be
dried for a minimum of 24 hours at 90 - 100 ° C before the transformer
is filled with oil.

If the complete transformer is placed in an oven for drying, it is
recommended that it last for 48 hours at 90 - 100 ° C. If the peak
temperature is below 60 ° C when the transformer is opened, or if
there is a leak in the transformer, the tank will draw in air due to vacuum.

The transformer is filled at 35 - 40 ° C at the factory.