IG-302-EN version 01; 18/11/2020
16
Commissioning
General instructions
transforma
.bst-pm: Distribution transformers, hermetically
sealed, immersed in dielectric liquid from 16 to 100 kVA
(single-phase) / from 25 to 315 kVA (three-phase)
6. Commissioning
6.1. Checking the transformer before commissioning
6.1.1. Mineral oil insulated transformers
Once the transformer is connected to the power networks,
and before connecting the electrical power source, the
following checks should be performed:
1.
Check that the network values and the transformer's
rated voltage match.
2.
If the transformer has these instruments, check the
correct oil level in the oil level indicator, if fitted.
3.
Energise the transformer with no load connected
and check its correct connection and regulation by
measuring the values in the secondary.
Failure to follow these safety precautions may
result in death by electric shock or irreversible
damage to the transformer or to the electrical
installation.
• The tap changers should always be operated without
electrical power, ensuring the handle is well locked
and in its working position.
• Check that the electrical voltage applied matches the
transformer's rated voltage. Contact
Ormazabal
in
the case of any anomaly.
• If an adjustment is required after commissioning the
transformer, follow the safety instructions specified
in section 7.1 of these general instructions, titled
“Access for maintenance operations”.
4.
Regulate the transformer's voltage using the corres-
ponding tap changer, taking into account the safety
precautions.
Figure 6.1.
Tap changer in transformer detail
a.
If the transformer has a no-load tap changer:
i.
The no-load voltage tap changers must always
be operated without electrical power, ensuring
the handle is well locked and in its working
position.
ii.
Check that the electrical voltage applied
matches the transformer's rated voltage. Contact
Ormazabal
in the case of any anomaly.
iii.
If an adjustment is required after commissioning
the transformer, follow the safety instructions
specified in section 7.1 of these general
instructions.
5.
Keep the transformer energised with no-load for at
least 12 hours, checking that there are no anomalies in
any of the transformer instruments.
6.
Progressively apply the load until operating power is
achieved, while ensuring that transformer temperature
does not go over 105°C. In the case of transformers for
renewable energy sources, connect to the generation
source in low generation conditions and let it increase
naturally.
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