Signals; Settings - ABB RELION REX640 Technical Manual

1MRS759142 C
4.5.3.7
4.5.3.8
Table 731: ROVPTOV Group settings (Basic)
Parameter Values (Range)
Start value
Operate delay time
Table 732: ROVPTOV Non group settings (Basic)
Parameter Values (Range)
Operation
REX640
Technical Manual
In compensated and isolated neutral systems, the system neutral voltage, that is, the
residual voltage, increases in case of any fault connected to earth. Depending on the
type of the fault and the fault resistance, the residual voltage reaches different values.
The highest residual voltage, equal to the phase-to-earth voltage, is achieved for a
single-phase earth fault. The residual voltage increases approximately the same
amount in the whole system and does not provide any guidance in finding the faulty
component. Therefore, this function is often used as a backup protection or as a release
signal for the feeder earth-fault protection.
The protection can also be used for the earth-fault protection of generators and motors
and for the unbalance protection of capacitor banks.
The residual voltage can be calculated internally based on the measurement of the
three-phase voltage. This voltage can also be measured by a single-phase voltage
transformer, located between a transformer star point and earth, or by using an open-
delta connection of three single-phase voltage transformers.

Signals

Table 729: ROVPTOV Input signals
Name
URES
BLOCK
Table 730: ROVPTOV Output signals
Name
OPERATE
START

Settings

Unit
0.010...1.000 xUn
40...300000 ms
Unit
1=on
5=off
Type Default Description
SIGNAL - Residual voltage
BOOLEAN 0=False Block signal for activating the blocking mode
Type Description
BOOLEAN Operate
BOOLEAN Start
Step Default
0.001 0.030
1 40
Step Default
1=on
Section 4
Protection functions
Description
Residual overvoltage start value
Operate delay time
Description
Operation Off / On
785