6 Commissioning
Maschinenfabrik Reinhausen GmbH 2020
177
5293079/01 EN
VACUTAP
®
VM-Ex
Prior to commissioning the transformer, check whether the motor-drive unit
and on-load tap-changer are correctly coupled and that the motor-drive unit
functions correctly.
Tests on the motor-drive unit
1. Perform function checks as described in relevant MR operating instruc-
tions for motor-drive unit.
2.
NOTICE!
An incorrectly coupled motor-drive unit will lead to damage to
the on-load tap-changer. Undertake trial tap-change operations across the
entire range of settings. Ensure that in each operating position, the tap po-
sition indicators of motor-drive unit and on-load tap-changer (inspection
window in the on-load tap-changer head) match.
Dielectric tests on transformer wiring
► Note information relating to dielectric tests on transformer wiring in rele-
vant MR operating instructions for motor-drive unit.
6.1.4 High-voltage tests on the transformer
Note the following points before performing high-voltage tests on the trans-
former:
▪ Ensure that the oil compartment of the on-load tap-changer is completely
filled with insulating fluid.
▪ Ensure that all protective devices for the on-load tap-changer are function-
ing correctly and are ready for use.
▪ Ensure that the ground connections on the motor-drive protective housing
and protective housing fastening are free of paint.
▪ Only perform high voltage test if motor-drive unit door is closed.
▪ Disconnect external connections to electronic components in the motor-
drive unit to prevent damage from overvoltage.
▪ When connecting the motor-drive unit's supply voltage, only use the cable
bushings in the protective housing base intended for lead insertion.
▪ Guide all ground connecting leads to one central connection point (estab-
lishment of suitable reference earth).
▪ Disconnect all electronic components before the high voltage test. Before
a dielectric test of the wiring, remove all devices with a withstand voltage
of < 1000 V.
▪ Remove leads used for testing before the high voltage test as these func-
tion as antennas.
▪ Wherever possible, route the measurement leads and data leads sepa-
rately to the energy cables.
Contact the manufacturer if you have any questions about possible sources
of danger.