User Manual

3UG4.1 line monitoring relay
6.6 3UG4615 / 3UG4616 line monitoring relays
3UG4 / 3RR2 monitoring relays
Manual, 02/2013, NEB927043002000/RS-AA/002
131
Monitoring
The 3UG4615 / 3UG4616 line monitoring relays have two output relays. With output
relay K1, a three-phase system is monitored for undervoltage. With output relay K2, a three-
phase system is monitored for overvoltage.
The output relays respond in accordance with the set relay switching behavior (closed-circuit
principle NC or open-circuit principle NO).
If a fault occurs (phase failure, incorrect phase sequence, voltage undershoot or voltage
overshoot), the output relays switch in accordance with the relay switching behavior. In the
case of voltage undershoot or voltage overshoot, the output relays do not respond until
expiry of the set tripping delay time (U▼Del and U▲Del).
In the case of incorrect direction of rotation, the devices immediately shut down.
The display indicates the following voltages in the case of the line monitoring relays:
● 3UG4615: Line-to-line voltage between L1 and L2, L1 and L3, L2 and L3
● 3UG4616: Line-to-neutral voltage between L1 and N, L2 and N, L3 and N
Thanks to a special measuring method, a phase failure is detected with certainty despite
wide-range voltage from 160 to 690 V AC and reverse power of up to 80 % from the load in
the case of regenerative power recovery.
On failure of one of the phases (or neutral conductor failure for the 3UG4616 line monitoring
relays), the output relays drop out immediately to protect the application from any damage
that may result. Set delay times have no effect on the phase failure monitoring.
Note
The 3UG4615 and 3UG4616 line monitoring relays are only suitable for line frequencies of
50 / 60 Hz!
You will find the switching states of the output relays below in section "Function diagrams"
and in Chapter "Diagnostics (Page 134)."