Tettex TTR 2795, Operating Instructions Manual

Page: 19 / 111

Connection and Setup 15
If there is no secondary neutral
connection the X0 lead (Blue Lead,
White plug) should be plugged into the X1
lead (Brown lead, White plug).
The connections should be made as follows:
Transformer Terminal TTR Connection
ANSI, IEEE IEC, VDE AS
(Australian) “H” (Green Plugs) “X” (White plugs)
H1 U A Brown
H2 V B Black
H3 W C Grey
H0 N N Blue
X1 u a Brown
X2 v b Black
X3 w c Grey
X0 n n Blue
If the three-phase transformer is equipped with a tertiary winding this should be tested in the same manner as the
secondary. The transformer is energized using the high voltage windings (H0 to H3) with X0 to X3 connected to the
tertiary.
4.7 Current Transformers
Care has to be made to ensure that the current transformer is connected correctly
otherwise there is risk of damage to the CT and Instrument. There is also the risk of injury.
When testing CT not using the CT setting on the software, care has to be taken to ensure
that the energization voltage does not cause saturation of the transformer core. It is
recommended that the test voltage is limited to 10VAC unless it is certain that the CT can
tolerate a higher voltage.
If the CT saturates at 10VAC try using either the CT measurement mode or use 1V
energization. This is a problem that is more likely to be encountered with smaller
transformers with a ratio of 20:1 or less, or with small cores such as “wedding ring” CTs.
Note the CT mode is an indication only mode, for checking if saturation is the problem. It
must not be used for measurement.