Siemens 7SA511 Testing the Fault Detection Systems, Overcurrent Fault Detection Test, Setting

7SA511 Line Protection Relay Acceptance Tests

Table 3-16.Signal and Trip Relay Test Settings

Addr.

2601

2602

2603

LCD Text

EMERG.O/C ON

I>> phases 2.00 I/In

T-I>> phases 0.30 s

5.Increase the input current (equally for all three phases) until it reaches 2.5IN. Wait at least 1 second after completing input adjustments to ensure that all time delays have expired before examining the results. Verify that Signal Relays 6, 7, 8, and 9 are closed. Signal Relay 4 should remain open. Trip Relays 2, 3, 4, and 5 should all be closed.

6.Decrease the input current on phase 1 to zero. Wait at least 1 second after completing input adjustments to ensure that all time delays have expired before examining the results. Verify that Signal Relays 6, 8, and 9 and Trip Relays 2, 4, and 5 remain closed. Signal Relay 7 and Trip Relay 3 should now be open and Signal Relay 4 should be closed.

7.Reduce the input current on all three phases to zero. Wait at least 1 second after completing input adjustments to ensure that all time delays have expired before examining the results. Verify that all relay contacts are open.

3.9 Testing the Fault Detection Systems

Check your relay model number to determine which test(s) you should perform to test the relay’s fault detection system. The available systems and corresponding tests are:

Overcurrent fault detection test, section 3.9.1 (all relay models) Voltage-controlled overcurrent fault detection test, section 3.9.2 (relay model

￿7SA511*-**A52/3-****)

Polygonal (dogbone) impedance fault detection test, section 3.9.3 (relay model 7SA511*-**A52-****)

3.9.1Overcurrent Fault Detection Test

This test checks the operation of the overcurrent fault detection element and the emergency backup overcurrent element. Testing requires the use of a three-phase voltage source and a single- phase current source. In this test, the three phase voltages are applied simultaneously to the voltage inputs while test current is applied sequentially to each of the four current inputs.

The overcurrent detection threshold value for phase currents (IPH>> ) is set at address 1601. The factory presetting is 1.8IN. The threshold value for ground currents (IE>) is set at address 1602 with the factory presetting of 0.50IN.

Prerequisite Settings

Addr.	LCD Text
7802	DIST.F.DET
7803	EMERG. O/C
2601	EMERG. O/C

Description

Select the type of fault detection system

Emergency overcurrent protection function

Turn emergency overcurrent protection on or off

Setting

OVERCURRENT EXIST

ON

3-16 July 27, 1995