ABB ret650, Technical Manual

Page: 224 / 670

Name Values (Range) Unit Step Default Description
U1> 1 - 200 %UB 1 30 Voltage start value (DT & IDMT) in % of
UBase for step 1
t1 0.00 - 6000.00 s 0.01 5.00 Definite time delay of step 1
t1Min 0.000 - 60.000 s 0.001 5.000 Minimum operate time for inverse curves
for step 1
k1 0.05 - 1.10 - 0.01 0.05 Time multiplier for the inverse time delay
for step 1
OperationStep2 Off
On
- - On Enable execution of step 2
U2> 1 - 100 %UB 1 45 Voltage start value (DT & IDMT) in % of
UBase for step 2
t2 0.000 - 60.000 s 0.001 5.000 Definite time delay of step 2
Table 145: ROV2PTOV Non group settings (basic)
Name Values (Range) Unit Step Default Description
GlobalBaseSel 1 - 6 - 1 1 Selection of one of the Global Base Value
groups
9.3.6 Monitored data
Table 146: ROV2PTOV Monitored data
Name Type Values (Range) Unit Description
ULevel REAL - kV Magnitude of measured
voltage
9.3.7 Operation principle
Two step residual overvoltage protection ROV2PTOV is used to detect earth (zero
sequence) overvoltages. The ground overvoltage 3U
0
is normally computed by
adding the input phase voltages. 3U
0
may also be input single phase by either
measuring directly from a voltage transformer in the neutral of a power transformer,
or from a secondary broken delta connection of a transformer with a star-grounded
primary. ROV2PTOV has two steps with separate time delays. If the ground
overvoltage remains above the set value for a time period corresponding to the chosen
time delay, the corresponding TRIP signal is issued.
The time delay characteristic is setable for step 1 and can be either definite or inverse
time delayed. Step 2 is always definite time delayed.
The voltage related settings are made in percent of the global phase-to-phase base
voltage divided by √3.
Section 9
1MRK 504 135-UEN A
Voltage protection
218
Technical manual