Application - ABB 615 series Technical Manual

1MAC059074-MB A
4.2.5.5
615 series ANSI
Technical Manual
curve type "Inverse reset", the reset time depends on the current during the drop-off
situation. If the drop-off situation continues, the reset timer is reset and the PICKUP
output is deactivated.
The "Inverse reset" selection is only supported with ANSI or the
programmable types of the IDMT operating curves. If another operating
curve type is selected, an immediate reset occurs during the drop-off
situation.
The setting Time multiplier is used for scaling the IDMT operation and reset times.
The setting parameter Minimum trip time defines the minimum desired operation time for
IDMT. The setting is applicable only when the IDMT curves are used
The Minimum trip time setting should be used with great care because the
operation time is according to the IDMT curve but always at least the
value of the Minimum trip time setting. More information can be found in
the IDMT curves for overcurrent
Timer calculates the pickup duration value PICKUP_DUR, which indicates the
percentage ratio of the pickup situation, and the set operating time, which can be either
according to DT or IDMT. The value is available in the monitored data view.
More information can be found in the
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.

Application

During a ground fault, 51NHA calculates the maximum current for the current feeder. The
value is sent over an analog GOOSE to other protection relays of the busbar in the
Protection functions
protection.
General function block features.
Section 4
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