Current Inputs - Siemens 7SR105 Rho User Manual

7SR105 Rho Description of Operation
Figure 2-8 LED Indication Label
2.8

Current Inputs

Four current inputs are provided on the Analogue Input module. Terminals are available for both 1 A and 5 A
inputs.
The current input is incorporated within the relay and is used for phase fault and earth fault protection.
Current is sampled at 1600 Hz for both 50 Hz and 60 Hz system frequencies. Protection and monitoring functions
of the relay use either the Fundamental Frequency RMS or the True RMS value of current appropriate to the
individual function.
The waveform recorder samples and displays current input waveforms at 1600 Hz.
The primary CT ratio used for the relay instruments can be set in the CT/VT configuration menu.
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