28
TRT33A Getting Started
5.7.
Tap Changer Control Unit
The external Tap Changer Remote cable is used for convenient tap changer testing.
After the TRT33A has measured a tap, if you choose to test next tap position, it stands by waiting for the
operator to move the transformer tap changer to the next tap position and continue the measurement by
entering a new name plate voltages.
The tap changer operation box on power transformers is normally not placed at the same place where
the TRT33A is placed. The Tap Changer Control Unit allows the operator to continue the next tap
measurement from the TRT33A position. It is performed by pressing
UP/DOWN
on the Tap Changer
Control Unit block.
The operator has to connect the Tap Changer Control cable from the TRT33A to the tap changer
operation box. An example of that connection is shown on the figure below.
When the appropriate connection is done, the operator has just to press
UP/DOWN
on the Tap Changer
Control Unit block to change the tap position.
Relays which are built-in
inside the TRT
Brown
Yellow
Green
Tap Changer
Control Cable
Figure 5-39: Connecting
Tap Changer control cable