ABB REU 523 - Page 21

1MRS 750942-MUM
Combined Overvoltage and Undervoltage Relay
Technical Reference Manual
REU 523
21
1)
The stage can be set out of operation in SGF. This state will be indicated by dashes on the LCD and
by “999” when parameters are read via the SPA bus.
Switchgroups and parameter masks
The settings can be altered and the operation characteristics of the relay in various
applications selected in the SG_ selector switchgroups. The switchgroups are
software based and thus not physical switches to be found in the hardware of the
relay. The switches can be set one by one.
A checksum is used for verifying that the switches have been properly set. The
figure below shows an example of manual checksum calculation.
Table 4.1.4.6-1 Setting values
Setting Description Setting range Default setting
U>/U
n
Set start value of stage U> as a multiple of
the rated voltage of the energizing input
• definite and inverse time 0.60...1.40 x U
n
1.20 x U
n
t> Operate time of stage U> in seconds at
definite-time characteristic
0.06...600 s 0.06 s
k> Time multiplier k> of stage U> at
IDMT characteristic
0.05...2.00 0.05
D/P> Drop-off/pick-up ratio for U> 0.95...0.99 0.97
U>>/U
n
Set start value of stage U>> as a multiple
of the rated voltage of the energizing input
• definite and inverse time
0.80...1.60 x U
n
1)
1.20 x U
n
t>> Operate time of stage U>> in seconds 0.05...600 s 0.05 s
k>> Time multiplier k>> of stage U>> at
IDMT characteristic
0.05...2.00 0.05
U</U
n
Set start value of stage U< as a multiple of
the rated voltage of the energizing input
• definite and inverse time 0.30...1.20 x U
n
0.30 x U
n
t< Operate time of stage U< in seconds at
definite-time characteristic
0.10...600 s 0.10 s
k< Time multiplier k< of stage U< at
IDMT characteristic
0.10...2.00 0.10
D/P< Drop-off/pick-up ratio of U< 1.01...1.05 1.03
U<</U
n
Set start value of stage U<< as a multiple
of the rated voltage of the energizing input
• definite and inverse time
0.30...1.20 x U
n
1)
0.30 x U
n
t<< Operate time of stage U<< in seconds at
definite-time characteristic.
0.10...600 s 0.10 s
k<< Time multiplier k<< of stage U<< at
IDMT characteristic.
0.10...2.00 0.10
CBFP Circuit-breaker failure protection 0.10...1.00 s 0.10 s