Siemens 7SA511 Nondirectional, Inverse Time Overcurrent Protection, Description Preset, Charac

7SA511 Line Protection Relay Chapter 5

Table 5-24.Settings for Directional, Definite Time Overcurrent Protection with Directional Comparison and Nondirectional Backup Element

Addr.

3105

3201

3203

3204

3210

3211

3212

3213

LCD Text

T-DELAY

E/F COMPAR

T-TRANSBLO

T-WAIT TB

E/F ECHO

T-ECHO-DEL

T-ECHO-IMP

T-ECHO-BLO

Description

Delay time for transmission and trip

Turn the ground fault definite time, directional comparison protection on or off

Transient blocking time, which must be longer than the transmission time

Waiting time before initiating transient blocking with missing reception signal

Turn the echo keying function on or off

Echo time delay

Duration of echo impulse

Echo blocking time

Preset

0.00s

ON

0.05s

•s

ON

0.20s

0.05s

0.40s

Options/Range

0.00•- 32.00 s

OFF

0.01- 32.00 s

0.00- 32.00 s

OFF

￿0.01 - 32.00 s

0.02- 32.00 s

0.01 - 32.00 s

5.15.3 Nondirectional, Inverse Time Overcurrent Protection (3300)

For nondirectional, inverse time overcurrent protection, the parameters are set in address block 3300. Table 5-25 lists the relay presettings and setting options available. Compare these presettings to the information on the completed worksheets and determine which settings you need to change to match your operating environment. When you have changed all of the necessary settings, follow the procedure described in section 5.3.4 to save the new settings.

Prerequisite Settings:

Addr.	LCD Text
7808	EARTH FAULT
1102	SYSTEMSTAR

Description	Preset
Type of earth (ground) fault protection	INVERSE TIME
System neutral condition	SOLIDLY
	EARTHED

Table 5-25.Settings for Nondirectional Inverse Time Overcurrent Protection

Addr.

3301

3302

3303

3304

3305

LCD Text

E/F I.T.

E/F CHARAC

Ie>

TIe>

T-BLOCK

Description

Turn the nondirectional, inverse time ground fault protection on or off

Select inverse time characteristic

Pickup ground current value

Trip delay time dial (multiplier)

Time during which ground fault protection is blocked when distance protection has picked up

Preset

ON

NORMAL INVERSE

0.20I/In

0.50s

1.30s

Options/Range

OFF

VERY INVERSE EXTREMELY INVERS

0.10- 4.00 I/In

￿0.00•- 32.00 s

0.00- 320.00 s

July 27, 1995 5-41