Siemens 7SA511 manual Exist Compensated Isolated, Earthfault, CT ERR CT ERR. F1 CT ERR. F2

7SA511 Line Protection Relay Programming the Relay

Prerequisite Settings:

Addr.	LCD Text
7807	ISOL. E/F
1102	SYSTEMSTAR

Description

Ground fault detection for ungrounded systems

System neutral condition

Preset

EXIST

￿COMPENSATED ISOLATED

Table 5-22.Settings for Ground Fault Protection for Ungrounded Systems

Addr.

3001

3002

3003

3004

3005

3006*

3007*

3008*

3009*

3010

LCD Text

EARTHFAULT

Ue>

Uph<

Uph>

Ie>

CT ERR. I1

CT ERR. F1

CT ERR. I2

CT ERR. F2

T-E/F

Description

Turn ground fault detection in ungrounded systems on or off

Threshold value for ground fault detection

Phase-to-ground voltage below which a ground fault is indicated

Phase-to-ground voltage that healthy phases will exceed during a ground fault

Threshold current value for directional determination of the ground fault

Secondary current for maximum angle error of the CT

Error angle of CT at I1current set in address 3006

Secondary current above which the angle error is constant

Error angle of CT at I2 current set in address 3008

Amount of time the displacement voltage must exist before ground fault pickup

Preset

ON

40V

40V

75V

0.050 A

0.050 A

0.0

1.000 A

0.0￿

1.0 s

Options/Range

OFF

10 - 100 V

10 - 100 V

10 - 100 V

0.003 - 1.000 A

0.003 - 1.600 A

0.0 - 5.0

0.003 - 1.600 A

0.0 - 5.0￿

1.00 - 320.00 s

5.15 High-Resistance Ground Fault Protection for Grounded Systems (Optional)

This section applies only to relay model numbers 7SA511*-**A5*-0/2**2/3.The type of high- resistance ground fault protection to be used is programmed at address 7808 as part of the relay’s Scope of Functions (see section 5.6). Skip this section if ground fault protection was programmed as non-existing, or if your relay model number does not match the one above.

*This parameter is not necessary for systems with an isolated neutral; however it is typically used for systems with a compensated grounding.

5-38 July 27, 1995