Voltage Based Inverse Definite Minimum Time Characteristics - ABB 615 series Technical Manual

1MAC059074-MB A
11.3
11.3.1
615 series ANSI
Technical Manual
Activating the BLOCK input alone does not affect the operation of the PICKUP output. It
still becomes active when the current exceeds the set Pickup value, and inactive when the
current falls below the set Pickup value and the set Reset delay time has expired.
Voltage based inverse definite minimum time
characteristics
IDMT curves for overvoltage protection
In inverse-time modes, the trip time depends on the momentary value of the voltage, the
higher the voltage, the faster the trip time. The trip time calculation or integration starts
immediately when the voltage exceeds the set value of the Pickup value setting and the
PICKUP output is activated.
The TRIP output of the component is activated when the cumulative sum of the integrator
calculating the overvoltage situation exceeds the value set by the inverse time mode. The
set value depends on the selected curve type and the setting values used. The user
determines the curve scaling with the Time multiplier setting.
The Minimum trip time setting defines the minimum trip time for the IDMT mode, that is,
it is possible to limit the IDMT based trip time for not becoming too short. For example:
General function block features
Section 11
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