Measurement functions
Table 88. Three-phase current measurement (CMMXU)
Characteristic
Value
Operation accuracy
At the frequency f = f
n
±0.5% or ±0.002 x I
n
(at currents in the range of 0.01...4.00 x I
n
)
Suppression of harmonics
DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,
…
RMS: No suppression
Table 89. Three-phase voltage measurement (VPPMMXU )
Characteristic
Value
Operation accuracy
At the frequency f = f
n
±0.5% or ±0.002 x U
n
(at voltages in the range of 0.01...1.15 × U
n
)
Suppression of harmonics
DFT: -50dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
RMS: No suppression
Table 90. Three-phase voltage measurement (VPHMMXU )
Characteristic
Value
Operation accuracy
At the frequency f = f
n
±0.5% or ±0.002 x U
n
(at voltages in the range of 0.01...1.15 × U
n
)
Suppression of harmonics
DFT: -50dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
RMS: No suppression
Table 91. Residual current measurement (RESCMMXU)
Characteristic
Value
Operation accuracy
At the frequency f = f
n
±0.5% or ±0.002 x I
n
(at currents in the range of 0.01...4.00 x I
n
)
Suppression of harmonics
DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,
…
RMS: No suppression
Transformer Protection and Control
1MRS756978 D
RET630
Product version: 1.1
Issued: 2011-05-18
58
ABB