Sices D-PRO, Technical Manual

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D-PRO Protection relay Technical Manual 19
INFORMATION! The measurement is valid only if the CTs of both A and B parts use the
same transformer ratio and the same measurement range (up to 01.08 version). Starting from
version 01.09 the measurement is valid even if TA with a different transformation ratio and /
or measurement range are used.
4.6.9
The device allows to acquire a fourth current measurement, which can be used for example
for a protection on the genset neutral (protection 50N and 51N). By default, the fourth measure
is not used.
It is possible to configure a digital input with the DIF.2704 function -
“Disable the protection on
the 4
th
current”: If the input is active, the thresholds are ignored and no faults are created in
case they are exceeded, even if they have been configured.
The controller provides the connection of a current transformer (CT) with the 5A secondary for
the measurement of the current through the JD connector or the use of a toroid (instead of the
CT) by means of the JC connector. Regardless of the type of external transformer used, then
you need to configure the controller once again through the parameter P.0119 (Type of
transformer for the auxiliary current), which can have the following values:
0
– C.T.
1
– Toroid.
•
Current transformer
Terminal Function
JD - 1 CTAux Input (S1) hot pole.
JD - 2 CTAux Input (S2) cold pole.
The JD terminals can be connected to an external current transformer with a 5A or 1A
secondary: the controller internally manages an automatic scale change that guarantees the
same measurement accuracy with both types of transformer.
The parameters P.0119 and P.0120 allow to configure the transformation ratio of the external
current transformer. For example, if you use a 60/5 current transformer, set P.0120=60 and
P.0121=5.
The parameter P.0122 allows to select if and how the auxiliary current is used:
0 - Not used.
1 - General use.
2 - Neutral on genset.
•
Toroid
Terminal Function
JC - 1 Input IAux (IN) hot pole.
JC - 2 Input IAux (RTN) cold pole.
The toroid transformation ratio must be configured on the controller through parameters
P.0125 and P.0126. For example, if you use a toroid with a 700 transformation ratio, set
P.0125=500 and P.0126=1.
The parameter P.0127 allows to select if and how the toroid current is used:
0 - Not used.
1 - General use.