3 Product description
Maschinenfabrik Reinhausen GmbH 2020
29
5293079/01 EN
VACUTAP
®
VM-Ex
3.2.4.1 Protective relay
3.2.4.1.1 Function description
The protective relay is looped into the circuit breaker tripping circuit, thus
protecting the on-load tap-changer and transformer in the event of a fault
within the on-load tap-changer oil compartment. It is tripped when the speci-
fied speed of flow from the on-load tap-changer head to the oil conservator
is exceeded due to a fault. The flowing insulating fluid actuates the flap valve
which tips over into position OFF. The contact in the dry-reed magnetic
switch is thereby actuated, the circuit breakers are tripped, and the trans-
former is de-energized.
The protective relay is a component of an on-load tap-changer filled with in-
sulating fluid and its properties conform to the respective applicable version
of IEC publication 60214-1.
Diverter switch operations at rated switching capacity or at permissible over-
load will not cause the protective relay to trip.
The protective relay responds to flow, not to gas accumulated in the protec-
tive relay. It is not necessary to bleed the protective relay when filling the
transformer with insulating fluid. Gas accumulation in the protective relay is
normal.
3.2.4.1.2 Setup/versions
Front view
Figure 9: RS 2001-Ex
1 Inspection window
2 Pressure equalization element