Functional description
14
VMD460-NA_D00001_05_M_XXEN/01.2020
3.2 Disconnection
As soon as at least one of the activated protective or monitoring functions has tripped,
the VMD460-NA issues a disconnection command via contacts K1 and K2 to the con-
nected interface switches. First K1 and then K2 are tripped with a delay of 50 ms.
3.3 (Re)connection and
special reconnections
3.3.1
(Re)connection and monitoring of the conditions
If the (re)connection conditions are fulfilled and the delay time for connection has
elapsed, the VMD460-NA enables the coupling of the generating plant to the network
automatically.
If no connection value is set, the respective response value of the corresponding pro-
tective function applies. It must be ensured that the response values of the protective
functions do not collide with those of the connection conditions.
3.3.2
Exceptions of automatic (re-)connection
In the event of a detected fault in one of the tripping circuits (interface switch fault), the
connection is controlled via the parameter "Menu -> Settings -> Dig. in. -> Fault mem-
ory".
•
Fault memory disabled:
If the fault is no longer present and the connection conditions have been fulfilled, the
VMD460-NA reconnects after the delay time for connection has elapsed. Up to 3 auto-
matic reconnection attempts are made in the event of a repeated interface switch fault.
If these also fail, a manual RESET is required.
•
Fault memory enabled:
If a fault is detected, there is no automatic (re-)connection or connection attempt. The
fault must be acknowledged manually via the RESET button to enable a connection.
3.3.3
Special reconnections
3.3.3.1
Reconnection after short interruptions
Menu: 3. Settings-> 1. General ->:
5. t
SHORT INT.
Special disconnection behaviour VDE-AR-N 4105:2018-11 and
CEI 0-21
Contrary to the above behaviour, K1 is tripped and K2 remains ener-
gised instead. A disconnection signal is only output via relay K2 if a
fault is detected in tripping circuit 1.
