Siemens 7SR12 Argus User Manual

7SR11 & 7SR12 Commissioning and Maintenance Guide
©2017 Siemens Protection Devices Limited Chapter 6 Page 34 of 72
definition reduce towards zero. It is therefore necessary to increase the residual current or to temporarily disable
the Wattmetric function to allow the directional boundary to be tested.
If the 67SEF Compensated Network setting is set to Enabled, the directional boundaries will be extended to
MTA+87º and MTA-87º.
MTA
Forward Reverse
Lag (point C) Lead (point A) Lead(point B) Lag (point D)
Pick-up Drop-off Pick-up Drop-off Pick-up
Drop-
off
Pick-up Drop-off
………….
MTA-85
………..
MTA+85
………
…
MTA-85
…………
MTA-85
………...
SEF
2.9.2 Definite Time Overcurrent (50SEF)
If DTL setting is small, gradually increase current until element operates.
If DTL is large apply 0.9x setting, check for no operation, apply 1.1x setting, check operation
Apply 2x setting current if possible and record operating time
P.U.
D.O.
&
TIMING
TESTS
Ph.
Dir
Char.
(NI EI VI LTI,
DTL)
Is
(A)
TM
Operate Current
Operate Time
P.U.
(Amps)
D.O.
(Amps)
Tol
2 x Is
(sec)
5 x Is
(sec)
Tol
I
4
Check correct indication, trip output, alarm contacts, waveform record.
Note that these elements can be set to directional.
If VTS action is set to BLOCK, this option should be tested. Apply balanced voltage and current. Reduce a-phase
voltage to cause a VTS condition. Increase a-phase current and check that the element does not operate.
If VTS action is set to Non-Directional, this option should be tested. Apply balanced voltage and current. Reduce
a-phase voltage to cause a VTS condition. Increase a-phase current and check that the element operates at its
normal setting. Reverse the voltage phase direction whilst checking that the element does not reset.
2.9.3 Wattmetric Protection
The Wattmetric Earth Fault protection requires that the SEF current setting is exceeded, the residual
power setting is exceeded and the directional element operated, simultaneously.
During testing of the 67SEF Wattmetric power setting it is essential that the current setting is also
exceeded. This can usually be achieved by applying current which is above setting to the SEF input
whilst applying single phase voltage, in anti-phase with the current, to any 1 phase to neutral voltage
input. In this way, the wattmetric power is equal to the product of the applied current and applied
voltage and can be adjusted by adjustment of the voltage magnitude.
Wattmetric Power
Setting
Current
Applied
Io
Dir
Operate Voltage
Vo
Calculated Po
Io x Vo

Siemens 7SR12 Argus Specifications

General

Brand	Siemens
Model	7SR12 Argus
Category	Protection Device
Language	English