ABB RELION 620 Series Technical Manual page 660

Section 4
Protection functions
4.5.4.5
4.5.4.6
654
The Timer calculates the start duration value START_DUR which indicates the
percentage ratio of the start situation and the set operate 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 relay
program. The influence of the BLOCK input signal activation is preselected with the
global setting 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, but the OPERATE 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 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.
Timer characteristics
PHAPTUV supports several operating curve types.
Table 604: Timer characteristics supported by IDMT operate curve types
Operating curve type
(5) ANSI Def. Time
(15) IEC Def. Time
(21) Inv. Curve A
(22) Inv. Curve B
(23) Programmable
Application
PHAPTUV detects low voltage conditions in power system elements, such as
generators, transformers, motors and power lines. Low voltage conditions are caused
by abnormal operation or a fault in the power system. PHAPTUV can be used in
combination with overcurrent protections. Other applications are the detection of a
no-voltage condition, for example, before the energization of a high voltage line, or an
automatic breaker trip in case of a blackout. PHAPTUV is also used to initiate voltage
correction measures, such as insertion of shunt capacitor banks, to compensate for a
reactive load and thereby to increase the voltage.
1MRS757644 F
620 series
Technical Manual