Sices D-PRO, Technical Manual

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40 D-PRO Protection relay Technical Manual
It activates if at least one of the genset voltages exceeds the threshold set in P.0323
(percentage of P.0102) for the time configured in P.0324.
Usually it is used in genset with insulated neutral and in medium voltage. The control is carried
out through the reading of a voltage that results from the “open triangle” of three VT with the
star primary and the secondary basically connected in series. Therefore, it requires a dedicate
input for the reading of the voltage (two cables).
Some protection relays on the market manage to recreate the signal of the open triangle
internally by using the measure of the star voltage.
Type: Alarm
Measuring: V59N - Homopolar voltages (100Vac)
Related parameters: P.0330 Maximum homopolar voltage threshold
P.0331 Maximum homopolar voltage delay
To disable: P.0331=0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status).
The controller measures the homopolar voltage, which results from the “open triangle” of the
three VT with the star primary and secondary basically connected in series. The reference
value measured is fixed to the hardware circuit at 100Vac.
It activates if the genset homopolar voltage exceeds the threshold set in P.0330 continuously
for time configured in P.0331.
Type: Alarm
Measuring: Generator frequency
Related parameters: P.0105 Rated frequency
P.0305 Minimum frequency threshold
P.0306 Minimum frequency delay
To disable: P.0306=0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status).
It activates if the genset frequency decreases below the threshold set in P.0305 (percentage
of P.0105) for the time configured in P.0306.
Type: Alarm
Measuring: Generator frequency
Related parameters: P.0105 Rated frequency
P.0307 Maximum frequency threshold
P.0308 Maximum frequency delay
To disable: P.0308=0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status).
It activates if the genset frequency exceeds the threshold set in P.0307 (percentage of P.0105)
for the time configured in P.0308.