De-energized tap-changer
WARNING
Do not operate the tap-changer while the transformer is
energized . Doing so can result in severe personal injury
and equipment damage .
The tap-changer provides a means of changing the voltage
ratio of a de-energized transformer without breaking the
transformer seal. It is operated by means of a rotatable
handle located on the side of the transformer. The tap-
changer is normally provided with five or seven positions,
as indicated on the tap-changer dial plate and transformer
instruction nameplate.
Insulating liquid
The insulating liquid in substation transformers is
either conventional transformer oil, R-Temp™ fluid or
Envirotemp™ FR3™ fluid. When makeup liquid is required,
use only approved fluid of the same type that is in the
transformer. It is important to check the proper liquid level
in the transformer at all times by periodically observing the
liquid level gauge. In addition, the dielectric strength of the
insulating liquid must be maintained at a high value.
It is recommended that a sample be taken of the liquid and
tested within one week after energization, and annually
thereafter.
Figure 9 . De-energized tap-changer .
8
SubStation tranSformer inStallation and partS replacement information
MN202002EN JUNE 2016
