Siemens 7SA511 manual Fault Type, Testing the Distance Zones

7SA511 Line Protection RelayAcceptance Tests

where	IP	-	test current
	IN	-	rated relay current
	VP	-	test voltage at threshold
	X±A	-	setting value X+A for positive X-axis, or setting
			value X-A for negative X-axis
	RA	-	setting value RA or RAE, for the R-axis
	KX	-	factor for X intersection according to Table 3-18
	KR	-	factor for R intersection according to Table 3-18

For phase-to-ground testing, the test current is applied to one phase and the ground current path. For phase-to-phase testing, the current must flow through the tested phases in opposite directions. To avoid errors, it is essential the two phase voltages be symmetrical. For the factory set values and IP/IN = 2, the resultant voltages will be as described in Table 3-17.

If different values have been set for RA1 and RA2, then RA1 is valid for phase angles between -45° and +45°, and between 135° and 225°. For other phase angles, setting value RA2 is decisive.

Table 3-17.Test Voltages VP With Test Current IP = 2IN and Factory Presets.

Fault Type

fp = 0￿ fp = 90￿ fp = 180￿ fp = 270￿= 90￿

3-phase

2-phase

1-phase

VP = 12V

VP = 24V

VP = 48V

VP = 24V

VP = 48V

VP = 48V

VP = 12V VP = 24V VP = 48V

VP = 5V

VP = 10V

VP = 10V

Table 3-18 gives the actors KX and KR for your own settings, for test angles fP = 90° and 0°, and the generally applicable formulas.

Table 3-18.Test Factors KX and KR for Settings Other Than Factory Presettings.

Fault Type

f KX

KR

p = 270￿/90￿

General

fp = 0￿/180￿ General

3-phase

2-phase

1-phase

1

2

1 + X E X L

1

sin φ P

2

sin φ P

1 + XE XL

sin φ P

1

2

1 + RE RL

1

cos φ p

2

cos φ P

1 + RE RL

cos φ P

3.10 Testing the Distance Zones

This test checks the parameters for the distance zones. Testing requires the use of a three-phase voltage source with clockwise rotation and a single-phase current source. Keep the voltage(s) in the untested phase(s) at approximately rated value.

Test Procedure

July 27, 1995 3-21