ABB RET650 Technical Manual page 221

1MRK 504 135-UEN A
Technical manual
Comparator
UL1 or UL12
U > U1>
Comparator
UL2 or UL23
U > U1>
Comparator
UL3 or UL31
U> U1>
MaxVoltSelect
Comparator
U> U2>
Comparator
U> U2>
Comparator
U > U2>
IEC08000012 V3 EN
Figure 95: Schematic design of Two step overvoltage protection (OV2PTOV)
Phase 1
Voltage Phase
Selector
OpMode1
Phase 2
1 out of 3
2 outof 3
Start
Phase 3
3 out of 3
&
Trip
Output
Logic
START
Step 1
Time integrator
TRIP
Timer t1
Phase 1
Voltage Phase
Selector
OpMode2
Phase 2
1 out of 3
2 outof 3
Start
Phase 3
3 out of 3
&
Trip
Output
Logic
START
Step 2
Timer
TRIP
t2
Section 9
Voltage protection
ST1L1
ST1L2
ST1L3
ST1
OR
OR
OR
OR
OR
TRIP
OR
IEC08000012-3-en.vsd
215