Inspection And Cleaning - Siemens GEAFOL Operating Instructions Manual

GEAFOL- / CARECO-Cast-resin Transformer/ Operating Instructions
Commissioning
The transformer must have been cleaned and it should not
contain any foreign objects (see also Install, page 7).
• Compare the technical data on the rating plate
attached to the transformer to the customer's
requirements.
• Tighten all contact connections to the torque stated in
Table 6.2.
NOTICE!
If the ambient conditions are outside the transformer spec-
ification (e.g. ambient temperature too low), the appropri-
ate conditions must be established before switching on.
When large transformers are switched on, in isolated cases
visible sparks may occur on the outside (especially in the
area of the core and the clamped parts), but these will
soon subside.
This effect occurs for reasons of physics and has no influ-
ence on operating safety; it is not a defect. Due to the low
attenuation, it may take the switch-on currents of GEAFOL
cast-resin transformers some time to decay. Refer to the
test report for the exact values. This must be considered
when selecting fuses and/ or relay times.
If protection settings are incorrect, the transformer will be
switched off during the transient response of the current.
This will lead to high excess voltages in the transformer
windings, where they may cause damage.

Inspection and cleaning

GEAFOL/CARECO transformers are practically maintenance-
free. If they are operated in very dusty installations, for in-
stance in rolling mills, we recommend cleaning several
times a year. Typically, once every year, the contact bolts,
warning functions, and the operation of any attached fans
should be checked.
The transformer must be switched off on all sides before
starting maintenance work. All terminals must be short-cir-
cuited and grounded. The safety regulations must be ob-
served.
DANGER!
Check that the transformer is de-energized before
approaching the transformer or you do not remove
protective covers. Secure the transformer against
unauthorised switching on.
NOTICE!
Dust and dirt are the main causes of transformer overheat-
ing and electrical short circuits. Dust deposits lead to
higher operating temperatures.
NOTICE!
Make sure that used tools and cleaning equipment are
completely removed from the transformer again after the
inspection.
NOTICE!
Do not use cleaning equipment with metal brushes. Loose
metal wires can cause severe damage to the transformer.
Do not use sharp-edged tools!
DANGER!
Do not switch on transformer until it is completely dry!
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