ABB 615 series Technical Manual page 639

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1MAC059074-MB A
615 series ANSI
Technical Manual
The operation of 47 can be described using a module diagram. All the modules in the
diagram are explained in the next sections.
GUID-66143AD1-B4FB-4D99-86F4-BEBF74F80E3E-ANSI V1 EN
Figure 316:
Functional module diagram
Level detector
The calculated negative-sequence voltage is compared to the set Pickup value setting. If
the value exceeds the set Pickup value, the level detector enables the timer.
Timer
Once activated, the timer activates the PICKUP output. The time characteristic is
according to DT. When the operation timer has reached the value set by Trip delay time,
the TRIP output is activated if the overvoltage condition persists. If the negative-
sequence voltage normalizes before the module trips, the reset timer is activated. If the
reset timer reaches the value set by Reset delay time, the operation timer resets and the
PICKUP output is deactivated.
The timer calculates the pickup duration value PICKUP_DUR, which indicates the ratio
of the pickup situation and the set trip time. The value is available in the monitored data
view.
Blocking logic
There are three operation modes in the blocking function. The operation modes are
controlled by the BLOCK input and the global setting in Configuration/System/Blocking
mode which selects the blocking mode. The BLOCK input can be controlled by a binary
input, a horizontal communication input or an internal signal of the protection relay's
program. The influence of the BLOCK signal activation is preselected with the global
setting Blocking mode.
The Blocking mode setting has three blocking methods. In the "Freeze timers" mode, the
operation timer is frozen to the prevailing value, but the TRIP output is not deactivated
when blocking is activated. In the "Block all" mode, the whole function is blocked and the
timers are reset. In the "Block TRIP output" mode, the function operates normally but the
TRIP output is not activated.
Section 4
Protection functions
633

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