6 Commissioning
Maschinenfabrik Reinhausen GmbH 2020
115
4983703/01 EN
VACUTAP
®
VV-Ex
2. Ground the motor-drive unit. To do this, only connect the motor-drive
unit's ground connection with protection against twisting to the trans-
former's ground connection.
Figure 107: Grounding screw on motor-drive unit
3. Connect housing of temperature sensor with grounding screw on on-load
tap-changer head.
6.1.3 Checking motor-drive unit
NOTICE
Damage to the on-load tap-changer / de-energized tap-changer!
Damage to the on-load tap-changer / de-energized tap-changer due to actu-
ation of the on-load tap-changer / de-energized tap-changer without insulat-
ing fluid.
► Ensure that the selector / de-energized tap changer is fully immersed in
insulating fluid and that the oil compartment of the on-load tap-changer is
completely filled with insulating fluid.
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.
