MR VACUTAP, Operating Instructions Manual

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6 Fault elimination
Maschinenfabrik Reinhausen GmbH 2020 40 5788897/03 EN VACUTAP
®
VVS
®
Fault description Action
Red message on monitoring unit If possible read out database and send to MR along with
error code.
Warning or tripping of Buchholz relay on transformer Notify manufacturer of transformer.
Deviation from desired value when measuring winding re-
sistance of transformer Contact manufacturer of transformer and, if necessary,
MR, and provide measured values.
Deviation from desired value during dissolved gas analysis
(transformer oil) Contact manufacturer of transformer and, if necessary,
MR, and provide measured values.
Deviation from desired value during transformer ratio test Contact manufacturer of transformer and, if necessary,
MR, and provide measured values.
Deviation from limit value for insulating fluids Carry out insulating fluid change, check oil conservator
breather of on-load tap-changer.
Table 4: Fault elimination
6.1 Tripping the protective relay and re-commissioning the
transformer
WARNING Danger of explosion!
Explosive gases in the protective relay can deflagrate or explode and result
in severe injury or death.
► Wait 15 minutes after switching off the transformer before beginning fur-
ther work on the protective relay so that the gases can dissipate.
► Ensure that there are no ignition sources such as naked flames, hot sur-
faces or sparks (e.g. caused by the build-up of static charge) in the imme-
diate surroundings and that none occur.
► De-energize all auxiliary circuits before beginning work.
► Do not operate any electrical devices during the work (e.g. risk of sparks
from impact wrench).
WARNING Danger of death or severe injury!
Danger of severe injury or death if on-load tap-changer and transformer are
insufficiently tested.
► Be sure to contact Maschinenfabrik Reinhausen to check on-load tap-
changer and transformer if the protective relay has tripped.
► Only use the equipment again when you are sure there is no damage to
the on-load tap-changer or transformer.
When the circuit breakers have been tripped by the protective relay, proceed
as follows:
1. Establish time of tripping.
2. Determine operating position of on-load tap-changer.
3. As a precaution, block the motor-drive unit by tripping the motor protective
switch to prevent the on-load tap-changer from being actuated by remote
control.