ABB RELION Series Technical Manual page 537

1MRS758755 A
REC615 and RER615
Technical Manual
GUID-DFB5F406-3F80-43B6-BD7E-93E94EFC680B V1 EN
Figure 277: Functional module diagram
Voltage detector
This module supervises voltage presence status value of a load switch or a circuit
breaker. The Voltage selection setting is used for selecting the phase-to-earth or
phase-to-phase voltages for voltage detection, and the Phase supervision setting
defines which phase or phases are monitored. The measured voltages are compared
with threshold settings.
If the measured voltage is larger than the limit value set by V live value setting and high
voltage lasts longer than the time set by V live time setting, the voltage presence is
interpreted as live. The corresponding phase specific output indicating live situation
is activated. Phase status is also reported to the phase selection logic module.
Once the voltage is lower than setting V live value, corresponding phase specific
output is deactivated and voltage live timer is reset.
If the measured voltage is lower than setting V dead value and low voltage situation
lasts longer than the time set by V dead time setting, the voltage presence is interpreted
as dead. The corresponding phase specific output indicating dead situation is
activated. Phase status is also reported to the phase selection logic module.
Once the voltage is larger than setting V dead value, the corresponding phase specific
output is deactivated and voltage dead timer is reset.
The Relative hysteresis setting can be used for preventing unnecessary oscillations if
the input signal varies slightly above or below the threshold setting. After leaving the
hysteresis area, the start condition has to be fulfilled again and it is not sufficient for
the signal to only return back to the hysteresis area.
The activation of the BLOCK input deactivates all outputs and resets internal timers.
Phase selection logic
General output U_LIVE is activated when setting Num of phases matches the number
of phases where voltage is set above high level setting. U_LIVE output is deactivated
immediately after voltage live condition is no longer met.
Section 6
Supervision functions
531