Blocking; Design - ABB REG650 Technical Manual

Section 8
Voltage protection
Voltage
UL1
UL2
UL3
IEC05000016 V1 EN
Figure 117: Voltage used for the inverse time characteristic integration
8.2.7.3
8.2.7.4
228
A TRIP requires that the overvoltage condition continues for at least the user set
time delay. This time delay is set by the parameter t1 and t2 for definite time mode
(DT) and by selected voltage level dependent time curves for the inverse time
mode (IDMT). If the START condition, with respect to the measured voltage
ceases during the delay time, the corresponding START output is reset.

Blocking

It is possible to block two step overvoltage protection (OV2PTOV) partially or
completely, by binary input signals where:
BLOCK:
BLKST1:
BLKST2:

Design

The voltage measuring elements continuously measure the three phase-to-earth
voltages or the three phase-to-phase voltages. Recursive Fourier filters filter the
input voltage signals. The phase voltages are individually compared to the set
value, and the highest voltage is used for the inverse time characteristic integration.
A special logic is included to achieve the 1 out of 3, 2 out of 3 or 3 out of 3 criteria
blocks all outputs
blocks all start and trip outputs related to step 1
blocks all start and trip outputs related to step 2
1MRK 502 034-UEN -
IDMT Voltage
Time
en05000016.vsd
Technical Manual