Siemens siprotec 7SA522 User Manual

1 Introduction
18
7SA522 Manual
C53000-G1176-C155-3
1.1 Overall Operation
The digital Distance Protection SIPROTEC
®
4 7SA522 is equipped with a powerful mi-
croprocessor system. This provides fully numerical processing of all functions in the
device, from the acquisition of the measured values up to the output of commands to
the circuit breakers Figure 1-1 shows the basic structure of the 7SA522.
Analog Inputs The measuring inputs (MI) convert the currents and voltages coming from the trans-
formers and adapt them to the level appropriate for the internal processing of the
device. The device has 4 current and 4 voltage inputs. Three current inputs are pro-
vided for measurement of the phase currents, a further measuring input (I
4
) may be
configured to measure the earth current (residual current from the current transformer
star-point), the earth current of a parallel line (for parallel line compensation) or the
star-point current of a power transformer (for earth fault direction determination).

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English