Element Blocking
The Vx overvoltage elements can be blocked by Binary Input Inhibit. This functionality should be
checked.
Element BI Inhibits
59Vx-1
59Vx-2
Check correct indication, trip output, alarm contacts, waveform record.
When testing is complete reinstate any of the disabled functions.
67 Directional Overcurrent – Phase
If the relay has Directional Overcurrent elements, the common direction polarizing can be checked
independently from the individual overcurrent elements and their settings. If Phase Rotation ACB is
selected in the CT/VT menu, this corresponds to negative phase sequence and the Forward and Reverse will
be automatically exchanged by internal relay configuration. The tests below describe normal ABC rotation and
the forward/reverse direction reversal will be experienced for ACB settings unless single phase voltages are
inverted. Directions for 3 phase testing will also be reversed unless the 3 phase supply rotation is reversed.
This can be achieved by swapping any 2 phase wires, for both current and voltage with a standard ABC test
supply. Direction Earth Fault direction is not affected by the Phase Rotation direction.
In the Instruments mode display, indication is provided in the Directional Meters menu which
displays current direction under P/F Dir as forward or reverse based on the output states of the directional
elements, i.e. whether they see forward current, reverse current or neither for each pole with respect to the
67 Char Angle setting in the Phase Overcurrent menu. This display and the equivalent Measured and
Calculated Earth Fault direction meters can be used as an aid to commissioning testing.
1. Check the direction of each pole in turn by connecting to the appropriate terminals. The following table
shows the polarizing quantity for each pole.
Table 9-10
Connections for Directional Polarity
Overcurrent Pole Polarizing Voltage
Phase A V
BC
Phase B V
CA
Phase C V
AB
2. Inject single phase rated current and apply single phase-phase rated voltage at the Char Angle (MTA)
phase angle setting, to each phase in turn. For each pole, monitor the directional display in the instrument
menu and check that indication of forward current (FWD) is displayed. To achieve the required forward charac-
teristic angle, the phase angle of the current should be greater than that of the polarizing voltage by the angle
setting.
3. Repeat all of the above with the current connections reversed. Indication should now be given of reverse
(REV) current flow.
Phase
A B C
Forward FWD FWD FWD
Reverse REV REV REV
4. Apply balanced 3 phase rated voltage and current with V
BC
voltage as a 0° reference and I
a
at the character-
istic angle. Increase current phase angle until the Fwd indication is extinguished. Record this angle in the table
below (Forward lead DO). Continue to increase/decrease the angle until the instrument reads Rev. Record the
angle (Reverse lead PU). Reduce the current angle until the Rev extinguishes (Reverse lead DO). and the Fwd
subsequently returns (Forward lead PU), recording the angles. Repeat the above tests, starting from the
Characteristic Angle, but reducing the current phase angle to record the directional boundaries in the
opposite (lag) direction. The recorded angle should be the angle at which the phase current leads the phase-
9.9.23
Functional Tests
9.9 Protection Functional Tests
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 491
C53000-G7040-C014-1, Edition 11.2019
To Next Page
Loading...
