DV Power TRT3 Series - Getting Started; Connecting TRT3 x to a Test Object

TRT3x Getting Started
M-T03XNN-205-EN 9
3 Getting Started
3.1 Connecting TRT3x to a Test Object
Before TRT3x has been connected to a test object (e.g. power transformer), the following steps have to be
verified:
• The test object is disconnected from its circuit in accordance with the national safety regulations and
is properly grounded to the protective earth.
• The transformer is completely de-energized.
• TRT3x itself should be properly grounded. To do this, the grounding screw on the top of TRT3x
should be connected to PE using the provided grounding cable.
Note: Always connect measuring cables to TRT3x first and then to the test object terminals.
Additionally, measuring cables can be connected to the test object terminals first, but
only if the test object terminals are grounded.
When disconnecting, always disconnect cables from the test object terminals first and
then from TRT3x. Additionally, measuring cables can be disconnected from TRT3x first,
but only if the test object terminals are grounded.
The grounding wire PE should be disconnected last.
Not following these instructions may cause life-threatening situations.
Cable test leads are terminated with the specially adjusted clips. The colors and markings of the test cables
are shown in the Table 1.
Table 1: Test lead colors and markings
If the primary neutral connection does not exist, the 1N (H0; N) lead should be left isolated from the
transformer (i.e. the test object) and from the other connection leads. It must be placed in such a way that it
is completely isolated from other connections or earth. No personnel should be in a position to touch it!
To maximize the accuracy and measurement repeatability, make sure all clamps have a good connection to
the test object and avoid any crossing between the measuring cables.
If the three-phase transformer has a tertiary winding, it should be tested the same way as the secondary.
The transformer is energized using the high voltage windings. Test leads 2U, 2V, 2W and 2N (X1, X2, X3
and X0; a, b, c and n) are in this case connected to the tertiary winding of the transformer.
IEC Test
Lead
Marking
ANSI
Test Lead
Marking
Australian
Test Lead
Marking
Transformer
Terminal
Voltage
Test Lead
Color IEC
Australian
Test Lead
Colors
Malaysian
Test Lead
Colors
1N
H0
N
Neutral
Blue
Black
Black
1U
H1
A
High
Red
Red
Red
1V
H2
B
High
Black
White
Yellow
1W
H3
C
High
Yellow
Blue
Blue
2N
X0
n
Neutral
Blue
Black
Black
2U
X1
a
Low
Red
Red
Red
2V
X2
b
Low
Black
White
Yellow
2W
X3
c
Low
Yellow
Blue
Blue