Table 4-2 Connections For Directional Polarity - Siemens 7SG11 Manual

1. Check the direction of each pole in turn by connecting to the appropriate terminals. Table 4-2 shows the
polarising quantity for each pole. Figure 4-4 shows a directional test circuit for one type of Argus 2.
Table 4-2 Connections for Directional Polarity
Overcurrent pole
Phase A
Phase B
Phase C
Earth-fault
2. Inject rated current and apply rated voltage at the CA (MTA) phase angle setting. Then, for each pole,
monitor the directional display in the instrument menu and check that indication of forward current (FWD) is
displayed.
3. Repeat all of the above with the current connections reversed. Indication should now be given of
reverse (REV) current flow.
4. To check the direction of the earth fault element on the Argus AG2xx series or the AG2xx-5xx series
when connected Ph-Ph, the 3Vo must then be applied to the residual voltage input.
To check the direction of the earth fault element on the AG2xx-5xx series of relays when connected Ph-N remove
the voltage from the phase under test, keeping the voltage healthy on the other two phases. Where only single
phase equipment is available then reverse voltage must be applied to the phase under test.
For all of the above tests inject residual current at the MTA into the earth fault input to confirm correct directional
operation.
Boundary of Operation
The purpose of this test is to ensure that the operating angles are correct for the forward and reverse zones of
each pole. Note that if a pole is programmed to operate in one direction only then only the angles for that
operating zone need be checked. Check that the required directional settings have been correctly applied,
including the characteristic angles.
Each directional operate zone has two boundaries of operation, at leading and lagging boundaries of I with
respect to V. To find the boundaries of operation for a particular pole, inject current and volts at the characteristic
angle and check that 'FWD' is indicated. Then adjust the phase angle to find the lagging drop-off boundary (ie I
lags V giving a negative angle), the 'FWD' indicator disappears at the drop-off angle. Set the angle back until the
'FWD' indicator reappears and adjust the phase angle to find the leading drop-off angle (positive angle).
To measure pick-up angles set the applied phase angle to be in the reverse zone and reduce the phase angle
until 'FWD' is displayed. Do for both leading and lagging boundaries.
The reverse zone boundaries can be found in a similar fashion. Initially inject at the characteristic angle plus 180
and check that 'REV' is indicated. Then find the pick-up and drop-off angles at the leading and lagging
boundaries.
Find the boundaries of the operate zones for each pole and record them in Table 4-16. If the test equipment is not
accurate enough to measure the boundary then an all or nothing test could be applied to verify the correct
direction indication.
©2013 Siemens Protection Devices Limited
Polarising voltage
V
BC
V
CA
V
AB
3V
0
7SG11 Argus User Manual
P20006 Page 22 of 37