Measurement functions
Table 31. Three-phase current measurement (CMMXU)
Characteristic
Value
Operation accuracy
Depending on the frequency of the measured current: f
n
±2 Hz
±0.5% or ±0.002 × I
n
(at currents in the range of 0.01...4.00 × I
n
)
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
RMS: No suppression
Table 32. Sequence current measurement (CSMSQI)
Characteristic
Value
Operation accuracy
Depending on the frequency of the measured current: f/f
n
= ±2 Hz
±1.0% or ±0.002 × I
n
at currents in the range of 0.01...4.00 × I
n
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
Table 33. Residual current measurement (RESCMMXU)
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: f/f
n
= ±2 Hz
±0.5% or ±0.002 × I
n
at currents in the range of 0.01...4.00 × I
n
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
RMS: No suppression
Table 34. Three-phase voltage measurement (VMMXU)
Characteristic
Value
Operation accuracy
Depending on the frequency of the voltage measured: f
n
±2 Hz
At voltages in range 0.01…1.15 × U
n
±0.5% or ±0.002 × U
n
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
RMS: No suppression
Table 35. Sequence voltage measurement (VSMSQI)
Characteristic
Value
Operation accuracy
Depending on the frequency of the voltage measured: f
n
±2 Hz
At voltages in range 0.01…1.15 × U
n
±1.0% or ±0.002 × U
n
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
Substation Merging Unit
1MRS758420 B
SMU615
Product version: 1.0
ABB
19
