MR ECOTAP VPD 3 30D-24, Руководство по эксплуатации

Страница: 118 / 132

14 Technical data
Maschinenfabrik Reinhausen GmbH 2021 118 8209941/00 EN ECOTAP
®
VPD
®
III 30D-24 / MD&C
14.4 Permitted voltage stresses
The specifications in this section only apply to use in mineral insulating oil in
accordance with IEC 60296. Data for alternative insulating fluids is available
on request.
This section describes the permitted voltage stresses on the tap winding and
on-load tap-changer.
When selecting the on-load tap-changer, you must check that the highest
stresses on the selector do not exceed the related rated withstand voltages.
Definition of insulation distances
a Between the beginning and the end of a tap winding and, for a coarse winding version, between the be-
ginning and the end of the coarse winding. Information for coarse tap selector connection in the (-) posi-
tion of the change-over selector:
When stressed with impulse voltage, the permissible withstand voltage "a" between the end of a coarse
winding connected with the K tap selector contact and the tap selector contact at the end of the tap
winding of the same phase must be adhered to.
a1 Between tap selector contacts of the winding of one tap position (connected or not connected)
2a1 Between the tap selector contacts of the winding across two tap positions (connected or not connected)
b Between the tap selector contacts of different phases and between change-over selector contacts of dif-
ferent phases which are connected with the beginning/end of a tap winding or with a tap selector con-
tact. The permissible voltages between the contacts for tap-changers for delta connections depend on
the positions of the change-over selector and tap selector. The different permissible withstand voltages
b1, b2 or b3 must therefore be noted for an insulation distance:
b1 Between selected contacts for different phases
b2 From the selected contact of one phase to non-selected contacts of other phases
b3 Between non-selected contacts of different phases
f Between tap selector contacts and (+) change-over selector contacts to ground. Different values apply
for the delta connection version:
f1 Between take-off lead and ground and in (+) position of change-over selector between (+) change-over
selector contacts and ground
f2 Between non-selected tap selector contacts and in (-) position of change-over selector between (+) con-
tacts and ground.
Additionally for coarse tap selector connection in (+) position of the change-over selector:
c1 From one (-) change-over selector contact to take-off lead of the same phase
c2 Between (-) change-over selector contacts of different phases
Table 28: Definition of insulation distances