1MRS750886-MUM
33
REU 513
User’s Guide
ABB Substation Automation
Products and Systems
1)
Note!
The reset time is normally 70 ms. In case the measured voltage that caused the
activation of the output relay falls below the set start voltage value within less than
the start time of the protection function stage added with the set minimum pulse
length for the activated relay, the reset time depends on the selected minimum pulse
length.
2.1.4.
Monitoring
The function of the relay can be monitored with the help of three indicators on the
relay front panel: a green READY LED, a yellow START LED and a red TRIP
LED. The basic protection functions are independent of the state of the indicators.
For function of the LEDs, refer to part A, “Operator’s instructions”.
Table 12: Stages U< and U<<
Feature
Stage U<
Stage U<<
Start voltage
• at definite-time and inverse-
time characteristics
0.30...1.20 x U
n
0.30...1.20
x
U
n
and
∞
Start time, typical
80 ms
50 ms
Time/voltage characteristic
• definite time
• operate times t< and t<<
0.10...600 s
0.10...600 s
• inverse-time characteristic
C-curve
C-curve
• time multipliers k< and k<<
0.10...2.00
0.10...2.00
Reset time
70 ms
1)
70 ms
1)
Drop-off/pick-up ratio
1.01...1.05
1.03
Operate time accuracy at
definite-time mode
±2 % of set value or
±25 ms
±2 % of set value or
±25 ms
Operate time accuracy at inverse-
time mode
±25 ms or the accuracy
appearing when the
measured voltage varies
±3 %
±25 ms or the accuracy
appearing when the
measured voltage varies
±3 %
Operation accuracy
• definite-time and inverse-time
characteristic
±1.5 % of set value
±1.5 % of set value
• positive-phase-sequence with
definite-time or inverse-time
characteristic
±
5 % of set value