Siemens 7SA511 Waveform Capture, Access Start End Port, Max. Rec. Time After Pickup, Exist on

7SA511 Line Protection Relay Chapter 6

Table 6-7.Ground Fault Measured Values Ungrounded Systems

Addr.

5801

5802

5803

5804

LCD Text

Iea =	A
Ier =	A
Iea[mA] =	mA
Ier[mA] =	mA

Description

Primary active component of the ground current based on the primary rated values specified at addresses 1105 and 1112

Primary reactive component of the ground current based on the primary rated values specified at addresses 1105 and 1112

Secondary active component of the of the ground current

Secondary reactive component of the of the ground current

6.7 Waveform Capture

In addition to the target log, event log, and measured values data described in the preceding sections, actual waveforms of the last fault can be recorded. Two prerequisite settings, described below, are required for waveform capture.

Prerequisite Settings:

Addr.	LCD Text
7806	FAULT RECRD
2801	FAULT REC.

Description

Indicate if waveform capture exists

Turn waveform capture on or off

Setting

EXIST ON

DIGSI“software is also required to view the actual waveforms. Reference B of this manual, “Hardware & Software,” discusses this software package in more detail.

For waveform capture, the sampling rate is 20 samples per power cycle. The starting point, ending point, and maximum recording time after a pickup is a function of the port being used to access the data. Table 6-8 provides the specifications.

Table 6-8.Waveform Capture Specifications.

Access	Start	End
Port	(prior to pickup)	(after trip)
Front	5 cycles	5 cycles
Rear	3 cycles	3 cycles

Max. Rec. Time After Pickup

145cycles

30cycles

Total Maximum Recording Time

155cycles

33cycles

When the data is accessed and processed by appropriate software it can be displayed in graphical format. An example of the waveform data and the way it may be displayed using DIGSI“ software is shown in Figure 6-1. The display shows the actual current and voltage waveforms on each phase and ground with markers for pickup (FD), trip (Trip), and drop-out (Reset). The points at which the fault occurred and the circuit breaker opened are also visible. The horizontal time line is in milliseconds. In this example, the results of an unsuccessful automatic reclose can be seen at approximately +390 milliseconds.

July 27, 1995 6-17