Siemens SIRIUS 3UG4 - Page 114

The display indicates the following voltages in the case of the line monitoring relays:
• 3UG4617: Line-to-line voltage between L1 and L2, L1 and L3, L2 and L3
• 3UG4618: Line-to-neutral voltage between L1 and N, L2 and N, L3 and N
Phase failure
In the case of a phase failure (or neutral conductor failure for the 3UG4618 line monitoring
relays), output relay K1 (relay contact 11‑12‑14) drops out without delay to protect the
application from any damage that may result. Set delay times have no e󹪜ect on phase failure
monitoring.
In the case of voltage undershoot, voltage overshoot, or asymmetry overshoot faults, output
relay K1 drops out after the set tripping delay time (Del).
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.
Incorrect direction of rotation
With the CO contact 21‑22‑24 of the output relay K2, for example, an incorrectly fed phase
sequence for a load connected downstream can be automatically corrected using an external
reversing combination. The Chapter "Circuit diagrams (Page 119)" provides an example of wiring
for automatic phase correction.
Note
The 3UG4617 and 3UG4618 line monitoring relays only evaluate the phase sequence while all
3 phases are present. For safety reasons, the phase sequence is not reevaluated after 2-phase
operation or a phase failure after which the third phase has appeared. In this case, the output
relay for the phase rotation remains in its last switching state. The phase sequence is not
reevaluated until after the device has been reset or all 3 phases have been simultaneously
switched o󹪜 and on again.
Note
The 3UG4617 and 3UG4618 line monitoring relays are only suitable for line frequencies of 50 /
60 Hz!
You will 󹪝nd the switching states of the output relays below in the Section "Function diagrams"
and in the Chapter "Diagnostics (Page 117)."
3UG4.1 line monitoring relay
6.7 3UG4617 / 3UG4618 line monitoring relays
SIRIUS 3UG4 / 3RR2 monitoring relay
114 Equipment Manual, 07/2021, NEB927043002000/RS-AD/005