The timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation and the set operation 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 input signal activation is
preselected with the global Blocking mode setting.
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.
The “Freeze timers” mode of blocking has no effect during the
inverse reset mode.
4.5.1.5 Timer characteristics
The operating curve types supported by PHPTOV are:
Table 384: Timer characteristics supported by IDMT operate curve types
Operating curve type
(5) ANSI Def. Time
(15) IEC Def. Time
(17) Inv. Curve A
(18) Inv. Curve B
(19) Inv. Curve C
(20) Programmable
4.5.1.6 Application
Overvoltage in a network occurs either due to the transient surges on the network
or due to prolonged power frequency overvoltages. Surge arresters are used to
protect the network against the transient overvoltages, but the IED protection
function is used to protect against power frequency overvoltages.
The power frequency overvoltage may occur in the network due to contingencies
such as:
Section 4 1YHT530004D05 D
Protection functions
470 615 series
Technical Manual
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