Operation mode
Description
Freq< + df/dt
A consecutive operation is enabled between the protection
methods. When the measured frequency is below the set
value of the
Start value Freq<
setting, the frequency gradi-
ent protection is enabled. After the frequency has dropped
below the set value, the frequency gradient is compared to
the set value of the
Start value df/dt
setting. When the fre-
quency gradient exceeds the set value, the module activates
the
START
and
STR_FRG
outputs. The time characteristic
is according to DT. When the operation timer has reached
the value set by the
Operate Tm df/dt
setting, the
OPER-
ATE
and
OPR_FRG
outputs are activated. If the frequency
gradient restores before the module operates, the reset
timer is activated. If the timer reaches the value set by
the
Reset delay Tm df/dt
setting, the operate timer resets
and the
START
and
STR_FRG
outputs are deactivated. The
OPR_UFRQ
output is not active when this operation mode is
used.
Freq> + df/dt
A consecutive operation is enabled between the protection
methods. When the measured frequency exceeds the set val-
ue of the
Start value Freq>
setting, the frequency gradient
protection is enabled. After the frequency exceeds the set
value, the frequency gradient is compared to the set value of
the
Start value df/dt
setting. When the frequency gradient
exceeds the set value, the module activates the
START
and
STR_FRG
outputs. The time characteristic is according to
DT. When the operation timer has reached the value set by
the
Operate Tm df/dt
setting, the
OPERATE
and
OPR_FRG
outputs are activated. If the frequency gradient restores be-
fore the module operates, the reset timer is activated. If the
timer reaches the value set by the
Reset delay Tm df/dt
set-
ting, the operate timer resets and the
START
and
STR_FRG
outputs are deactivated. The
OPR_OFRQ
output is not active
when this operation mode is used.
Table continues on the next page
Protection functions
1MRS757644 H
704
620 series
Technical Manual
