MR VACUTAP VR, Installation And Commissioning Instructions

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6 Assembly: Bell-type tank design
Maschinenfabrik Reinhausen GmbH 2015 112 4349315/00 EN VACUTAP® VR®
3.
NOTICE!
Carry out the transformer ratio test in all operating positions.
Always check the operating position reached through the inspection win-
dow in the on-load tap-changer head cover. Never overshoot the end
positions, which are indicated in the connection diagram supplied with
the delivery.
Figure 127: Inspection window
4. Once the transformer ratio test is complete, return on-load tap-changer
to its adjustment position (see supplied connection diagram of the on-
load tap-changer).
After the transformer ratio test, open the kerosene drain plug in the oil com-
partment if the on-load tap-changer is to be dried with kerosene in the trans-
former tank. After drying, the diverter switch insert must be removed, the
kerosene drain plug in the oil compartment closed and the diverter switch
insert refitted.
Measuring DC resistance on transformer
Note the measurement scenarios listed below and the associated maximum
measured currents when measuring DC resistance on the transformer.
The measured DC current is normally restricted to 10 % of the rated current
of the measured transformer winding in order to prevent the winding from
overheating.
Measure the DC resistance in the various on-load tap-changer operating po-
sitions. You need to distinguish here whether the measured current is inter-
rupted when changing operating position or not.
Without interruption
in measured current With interruption
(measured current = 0
A before change in
operating position)
Oil compartment empty Maximum 10 A DC Maximum 50 A DC
6.5