ABB 615 Series - Page 686

Table 586: Operation modes for operation logic
Operation mode Description
Freq< The function trips independently as the underfrequency ("Freq<")
protection function. When the measured frequency is below the set
value of the Pickup value Freq< setting, the module activates the
PICKUP and PICKUP_UFRQ outputs. The time characteristic is
according to DT. When the operation timer has reached the value set by
the
Trip Tm Freq setting, the TRIP and TRIP_UFRQ outputs are
activated. If the frequency restores before the module trips, the reset
timer is activated. If the timer reaches the value set by the Reset delay
Tm Freq
setting, the operation timer resets and the PICKUP and
PICKUP_UFRQ outputs are deactivated.
Freq> The function trips independently as the overfrequency ("Freq>")
protection function. When the measured frequency exceeds the set
value of the Pickup value Freq> setting, the module activates the
PICKUP and PICKUP_OFRQ outputs. The time characteristic is
according to DT. When the operation timer has reached the value set by
the
Trip Tm Freq setting, the TRIP and TRIP_OFRQ outputs are
activated. If the frequency restores before the module trips, the reset
timer is activated. If the timer reaches the value set by the Reset delay
Tm Freq
setting, the operation timer resets and the PICKUP and
PICKUP_OFRQ outputs are deactivated.
df/dt The function trips independently as the frequency gradient ("df/dt"),
rate-of-change, protection function. When the frequency gradient
exceeds the set value of the Pickup value df/dt setting, the module
activates the PICKUP and PICKUP_FRG outputs. The time
characteristic is according to DT. When the operation timer has
reached the value set by the
Trip Tm df/dt setting, the TRIP and
TRIP_FRG outputs are activated. If the frequency gradient restores
before the module trips, the reset timer is activated. If the timer reaches
the value set by the
Reset delay Tm df/dt setting, the operation timer
resets and the PICKUP and PICKUP_FRG outputs are deactivated.
Freq< + df/dt A consecutive operation is enabled between the protection methods.
When the measured frequency is below the set value of the Pickup
value Freq< setting, the frequency gradient protection is enabled. After
the frequency has dropped below the set value, the frequency gradient
is compared to the set value of the
Pickup value df/dt setting. When the
frequency gradient exceeds the set value, the module activates the
PICKUP and PICKUP_FRG outputs. The time characteristic is
according to DT. When the operation timer has reached the value set by
the
Trip Tm df/dt setting, the TRIP and TRIP_FRG outputs are
activated. If the frequency gradient restores before the module trips, the
reset timer is activated. If the timer reaches the value set by the
Reset
delay Tm df/dt setting, the operation timer resets and the PICKUP and
PICKUP_FRG outputs are deactivated. The TRIP_UFRQ output is not
active when this operation mode is used.
Table continues on next page
Section 4 1MAC059074-MB A
Protection functions
680 615 series ANSI
Technical Manual