Siemens 3UG4 - Parameters; Nominal line voltage; (Warning) threshold for voltage asymmetry

3UG4 / 3RR2 monitoring relays
Manual, 05/2016, NEB927043002000/RS-AC/004
363
Parameters
B
Nominal line voltage
The nominal voltage is the value of the electrical voltage during normal operation specified
by the manufacturer. The nominal voltage is usually stated with a maximum permissible
tolerance range. In Europe, the nominal value of the line voltage, the nominal line voltage, is
230 V (line / neutral) or 400 V (line / line).
(Warning) threshold for voltage asymmetry
Voltage asymmetry is the difference between the highest and the lowest phase voltage in
relation to the highest phase voltage (Ux-y max - Ux-y min) / Ux-y max.
Note
Deviation from the definition according to IEC/NEMA
The definition given above for voltage asymmetry deviates from the definition according to
IEC/NEMA. It usually results in a greater value for voltage asymmetry than that arrived at
from the definition according to IEC/NEMA, so that a higher
level of measuring accuracy is
achieved.
Voltage asymmetry can be parameterized as "Threshold for voltage asymmetry" or as
"Warning threshold for voltage asymmetry" (only on devices for IO-Link).
If the warning threshold is reached on device variants for IO-Link, this is transmitted cyclicly
via IO-Link and the relevant bits are set in the diagnostics data set or the semiconductor
output (terminal C/Q) is switched in SIO mode.
If the threshold has been reached, the output relays are switched accordingly and an IO-Link
message may be sent.
Possible indications on the display:
Asy (threshold), possibly Asy! (warning threshold)