Measurement Modes; Timer Characteristics - ABB RELION 620 Series Technical Manual

1MAC504801-IB E
4.1.1.5
4.1.1.6
620 series ANSI
Technical Manual

Measurement modes

The function operates on four alternative measurement modes: "RMS", "DFT", "Peak-to-
Peak" and "P-to-P + backup". The measurement mode is selected with the setting
Measurement mode.
Table 88: Measurement modes supported by 51P/50P stages
Measurement mode
RMS
DFT
Peak-to-Peak
P-to-P + backup
For a detailed description of the measurement modes, see the
Measurement modes

Timer characteristics

51P/50P supports both DT and IDMT characteristics. The user can select the timer
characteristics with the Operating curve type and Type of reset curve settings. When the
DT characteristic is selected, it is only affected by the Trip delay time and Reset delay time
settings.
The protection relay provides 16 IDMT characteristics curves, of which seven comply
with the IEEE C37.112 and six with the IEC 60255-3 standard. Two curves follow the
special characteristics of ABB praxis and are referred to as RI and RD. In addition to this,
a user programmable curve can be used if none of the standard curves are applicable. The
DT characteristics can be chosen by selecting the Operating curve type values "ANSI Def.
Time" or "IEC Def. Time". The functionality is identical in both cases.
The timer characteristics supported by different stages comply with the list in the IEC
61850-7-4 specification, indicate the characteristics supported by different stages:
Table 89: Timer characteristics supported by different stages
Operating curve type
(1) ANSI Extremely Inverse
(2) ANSI Very Inverse
(3) ANSI Normal Inverse
(4) ANSI Moderately Inverse
(5) ANSI Definite Time
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