IG-049-EN version 02; 02/10/2017
21
General Instructions
ormaset
Kiosk-type prefabricated transformer substation
Operations sequence
10.3. Commissioning
First check that the primary voltage (medium voltage) of
the distribution transformer is suitable for the installation
project. This information is printed on the distribution
transformer name plate and in the test protocol.
Before commissioning the transformer substation,
check that the transformer tap changer is in the position
corresponding to its maximum rated voltage and that it
is interlocked. In the case of a multi-voltage transformer
in medium voltage, check that the rated voltage of the
transformer matches the network service voltage.
The tap changers must always be actuated without
voltage in the circuit.
Power the medium voltage switchgear with the transformer
at no-load (fuse holder bases of the low voltage distribution
board open).
When commissioning the transformer substation, check
the operating voltage from the low voltage side (fuse-
holder bases). Proceed as follows if this does not match the
set value:
1.
Shut down the medium voltage switchgear
[3]
.
2.
Check the absence of voltage in the medium voltage
switchgear and in the low voltage distribution board.
3.
Earth the medium voltage switchgear and the flatbars
of the secondary of the distribution transformer in low
voltage.
4.
Unlock the transformer tap changer to adapt it to the
required power voltage by turning the switch back one
position.
With the distribution transformer connected to the medium
voltage network at no load, check the service voltage from
the distribution board in low voltage. Measure the voltage
on the low voltage distribution board to check the correct
connection and position of the tap changer.
If the service voltage is incorrect, follow the steps again
until the service voltage on the low voltage distribution
board is appropriate.
[3] Check the procedure in the General Instructions document included with the medium voltage switchgear.
Summary of Contents for Ormazabal ormaset
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