15
RMO60TD Getting Started
6.2 Tap Changer test
The
winding resistance of individual taps of a power transformer’s tap changer can be measured by
using RMO60TD’s Tap Changer (TapC). Also, it can be used to control the transformer tap changer.
This is a user-friendly way of winding resistance measurement and tap changer control, since automatic
measurement is possible without need to remove the current between each tap change. If the tap
changer is faulty, this may cause damage to the instrument. In order to avoid this, the inputs of the
instrument are protected during switching.
From the Current outputs, RMO60TD injects a constant current into the power transformer. From this
current value and the voltage measured, the winding resistance is calculated. An interruption caused by
a defective tap changer results in a comparatively high measured values of current ripple.
Setting the Measurement Parameters
Turn
on RMO60TD with the power switch on the back of the test set.
The display shows the
Current
menu and the green LED lights up. Press
SET
to go to the
TapC
menu.
In the
TapC
menu, define a test current for the test (here
10 A
). The following values can be
chosen: 1 A, 2 A, 5 A, 10 A, 20 A.
To do so, set the value of your choice by means of the
UP/DOWN
buttons. In the TapC menu of
RMO60TD, current output value is rated continuously at 20 A or less. Define the memory position (here
MEMORY:123
). Using
RIGHT
move the cursor to the memory location position, then using
UP/DOWN
select desired memory position to which obtained results would be saved.
By pushing
Ω
, resistance and current ripple measured results will remain registered in internal memory
of RMO60TD, and the memory position is automatically switched over to the next memory position.
These results can be recalled later by selecting that position number.
Note:
Only Ch:1 (left channel) is active channel.
Figure 6-10:
Connecting a test
object to RMO60TD
Figure 6-11:
The
TapC
menu
Test current
Memory position
Menu name
Active channel
Time and Date
