Sices D-PRO, Technical Manual

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18 D-PRO Protection relay Technical Manual
The maximum current that the device can directly measure is 6Aac, beyond which the
measurement circuit gets saturated. The controller is still able to measure, but with gradually
decreasing precision, down to about 25 A
only for transient situations , such as measuring
overcurrent or short circuit currents on the plant, by using an algorithm to compensate for the
saturation of the measurement circuits.
The measuring is carried out through the controller CTs.
4.6.5
The current A measure (upper part) usually is the one on top of the genset and has to be
carried out by current transformers (CTs) only.
With the parameters P.0110 and P.0111, you set the current values of the CTs primary and
secondary (by setting one of the two values to zero, the current will not be measured).
Terminal Function
JE - 1 CT1 Input (S1) hot pole.
JE - 2 CT1 Input (S2) cold pole.
JE - 3 CT2 Input (S1) hot pole.
JE - 4 CT2 Input (S2) cold pole.
JE - 5 CT3 Input (S1) hot pole.
JE - 6 CT3 Input (S2) cold pole.
4.6.6
The current B measure (lower part) usually is the one on bottom of the genset and has to be
carried out by current transformers (CTs) only.
With the parameters P.0115 and P.0116, you set the current values of the CTs primary and
secondary (by setting one of the two values to zero, the current will not be measured).
Terminal Function
JF - 1 CT1 Input (S1) hot pole.
JF - 2 CT1 Input (S2) cold pole.
JF - 3 CT2 Input (S1) hot pole.
JF - 4 CT2 Input (S2) cold pole.
JF - 5 CT3 Input (S1) hot pole.
JF - 6 CT3 Input (S2) cold pole.
The D-PRO protection relay measures the power on the current B.
4.6.7
The differential current measure is an absolute value that corresponds to the difference
between the measurements of each phase of the currents A and B. It is used in protections
87T and 87G.
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.
4.6.8
The load average current measure corresponds to the average between the measurements
of each phase of the currents A and B. It is used in protections 87T and 87G.