ABB REB500 - Combined Over- and Undervoltage Release

Section 6 1MRK 505 350-UEN
Additional functions
54 Technical Manual
Distributed busbar protection REB500
6.1.1 Combined over- and undervoltage release
The measurement of the undervoltage function is derived from the phase voltages
(U
L1
, U
L2
, U
L3
).
The measurement of the overvoltage function is derived from the neutral voltage or
is calculated from the phase voltages (3U
0
= U
L1
+ U
L2
+ U
L3
) or is fed externally
(3U
0
).
In the detailed view the voltage level can be set and the function can be activated.
In a combination of over- and undervoltage function (within a bay
unit or in the complete system) the overvoltage function has an
effect on the neutral system of the busbar protection (SSS_I0), and
the undervoltage function of the remaining functions (see also
release matrix in Section 6.2.2)
Figure 22 Voltage Release – Combined voltage release