Operation Manual 37107F
MFR 3 - Multi Function Relay
© Woodward
Page 93/165
Dead Bus Start
If the busbar is in a voltage-free state, the direct connection (dead bus start) of the GCB or MCB may be carried
out. If both connect commands are issued simultaneously, priority is given to the MCB if the input "Enable
MCB" (terminal 53) is energized.
NOTE
The MCB is never opened except in a mains failure function.
Parameter
108
GCB dead bus op.
ON
Dead bus start GCB
ON/OFF
ON
................ A dead bus start is performed in the event of a de-energized busbar
and an open MCB. The prerequisite for the dead bus operation to in-
itiate is the detection of operating conditions, which correspond to
the configured specifications below. The subsequent screens of this
function are displayed.
OFF
.............. A dead bus start is not performed, and the subsequent screens of this
function are not displayed.
Parameter
109
GCB dead bus op.
df max 0.00Hz
Dead bus start: max. permissible differential frequency GCB
0.05 to 5.00 Hz
The prerequisite to issuing a close command is that the monitored generator fre-
quency does not deviate from the generator rated frequency by more than the value
configure here.
Parameter
110
GCB dead bus op.
dV max 00.0%
Dead bus start: max. perm. differential voltage GCB
00.1 to 20.0 %
The prerequisite to issuing a close command is that the monitored generator voltage
does not deviate from the generator rated voltage by more than the percentage con-
figure here.
Parameter
111
GCB dead bus op.
max.time 000s
Dead bus start: max. time to close the GCB
0 to 999 s
If the GCB is to be closed onto a dead busbar, this timer is initiated at the start of
the breaker closing sequence. If the breaker fails to close before the configured
time expires, a class F1 alarm is issued.
Tripping of class F1 alarm
Parameter
112
MCB dead bus op.
ON
Dead bus start MCB
ON/OFF
ON
................ A dead bus start is performed in the event of a de-energized busbar
and an open GCB. The subsequent screens of this function are dis-
played.
OFF
.............. A dead bus start is not performed.
