causes an immediate reset. With the reset curve type "Def time reset", the reset
time depends on the Reset delay time setting. With the reset curve type "Inverse
reset", the reset time depends on the current during the drop-off situation. The
START output is deactivated when the reset timer has elapsed.
The "Inverse reset" selection is only supported with ANSI or user
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 operate and reset times.
The setting parameter Minimum operate time defines the minimum desired operate
time for IDMT. The setting is applicable only when the IDMT curves are used.
The Minimum operate 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 operate time setting. For
more information, see the
IDMT curves for overcurrent protection
section in this manual.
The timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation and the set operating time. The value is
available in the monitored data view.
Blocking logic
There are three operation modes in the blocking functionality. The operation modes
are controlled by the BLOCK input and the global setting "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 IED 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. In the "Block all"
mode, the whole function is blocked and the timers are reset. In the "Block
OPERATE output" mode, the function operates normally but the OPERATE output
is not activated.
4.1.1.5 Measurement modes
The function operates on four alternative measurement modes: "RMS", "DFT",
"Peak-to-Peak" and "P-to-P + backup". The measurement mode is selected with the
setting Measurement mode.
Section 4 1YHT530004D05 D
Protection functions
142 615 series
Technical Manual
To Next Page
Loading...
Need help?
General
