Siemens 7SR12 Argus - Page 302

7SR11 & 7SR12 Commissioning and Maintenance Guide
©2017 Siemens Protection Devices Limited Chapter 6 Page 18 of 72
Apply nominal 3 phase balanced voltage. Increase the voltage such that the a-b voltage is 110% of the Voltage
setting
Gradually increase the a-b phase current or balanced 3P current until Pickup LED operates. Confirm result of
Phase O/C test above.
Reduce the applied voltage to a level such that V
12
(V
AB
) phase-phase voltage is less than 90% of the setting.
Gradually increase the I
12
(I
AB
) phase-phase current until Pickup LED operates.
Note that these elements may be set as directional. If this is the case, the phase angle of the current must be set
with respect to the voltage to produce operation of the elements.
Voltage Setting (V, p-p)
Measured (V, p-p)
I Setting
Multiplier
Calculated PU
Measured
Tolerance
51-1 Pickup
51-2 Pickup
51-3 Pickup
51-4 Pickup
2.3.1.1 Element Blocking
The Voltage Controlled Overcurrent function can be set to Inhibit for VT Supervision operation. This functionality
should be checked. Apply balanced voltage and current. Reduce a-phase voltage to cause a VTS condition.
Increase 3P current until the element operates at its full setting, i.e. 51V settings are not used.
Element
VTS action
51-1
51-2
51-3
51-4
Check correct indication, trip output, alarm contacts.