Sices D-PRO, Technical Manual

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44 D-PRO Protection relay Technical Manual
Type: Alarm
Related parameters: P.0115 B- Primary of transformer
P.0116 B- Secondary of transformer
P.0119 Transformer type for the auxiliary current
P.0120 Primary of transformer for the auxiliary current
P.0121 Secondary of transformer for the auxiliary current
P.0122 Usage of auxiliary current
P.0123 Connection for auxiliary current
P.0368
Restricted earth fault threshold / Max. differential current (Aac)
P.0369 Restricted earth fault delay / Maximum differential current (s)
To disable: P.0369 =0 or P.0123=0
The protection is enabled only in case of absence of the disabling digital input (usually
combined to the circuit breaker status). The protection will be enabled if a valid current
measure is configured. In particular, P.0119 must be set to zero (0-C.T.), P.0122 must be set
to two (2-Neutral of generator) and the same transformation ratio must be configured for the
generator currents and auxiliary current. By parameter P.0123 is possible to configure the set
of currents (A or B) used to calculate the differential current.
The controller calculates the differential current (A
∑) as the instant sum of the three phase
currents and of the neutral current. Only in this case, the protection acts on the differential
current, not on the fourth current.
The protection will be activated if, according to the previous conditions, the measure of current
stays above P.0368 threshold uninterruptedly for P.0369 time span.
Type: Warning
Related parameters: P.0701 EXBUS Address.
To disable: -
The protection is always enabled.
It activates if the D-
PRO Protection relay doesn’t manage to communicate with the DST4602
controller.
Type: Warning
Related parameters: -
To disable:
-
The protection is always enabled.
It activates in the same communication bus if there is another D-PRO protection relay
configured with the same address.
See [1].
See [1].