Alstom MiCOM P545 - 8.4.2.2 Zone 1 reach check; 8.4.2.3 Zone 2 reach check

P54x/EN CM/La4 Commissioning
(CM) 10-42 MiCOM P543, P544, P545 & P546
CM
1. In order to facilitate testing of the Distance elements using test sets which do not
provide a dynamic model to generate true fault delta conditions, a Static Test Mode
setting is provided. This setting is found in the COMMISSIONING TESTS menu
column. When set, this disables phase selector control and forces the relay to use a
conventional (non-delta) directional line.
2. For lower specification test equipment that cannot apply a full three phase set of
healthy simulated pre-fault voltages, the VT supervision may need to be disabled to
avoid spurious pickup. This is achieved in the CONFIGURATION column, by setting
cell [0921: Supervision] to Disabled).
Connect the test equipment to the relay via the test block(s) taking care not to open-circuit
any CT secondary. If MMLG type test blocks are used, the live side of the test plug must be
provided with shorting links before it is inserted into the test block.
8.4.2.2 Zone 1 reach check
The zo
ne 1 element is set to be directional forward.
Apply a dynamic A phase to neutral fault, slightly in excess of the expected reach. The
duration of the injection should be in excess of the tZ1 timer setting, but less than tZ2
(settings found in the DISTANCE menu column). Observe that no trip should occur, and the
red Trip LED remains extinguished.
Reduce the impedance and reapply this to the relay. This procedure should be repeated
until a trip occurs. The display will show Alarms/Faults present and the Alarm and Trip LEDs
will illuminate. To view the alarm message press the read key , repeat presses of this key
should be used to verify that phase A was the Start Element. Keep pressing the  key
until the yellow alarm LED changes from flashing to being steadily on. At the prompt ‘Press
clear to reset alarms’, press the ‘C’ key. This will clear the fault record from the display
Record the impedance at which the relay tripped. The measured impedance should be
within +/- 10% of the expected reach.
Modern injection test sets usually calculate the expected fault loop impedance from the relay
settings, for those that do not:
 Connections for an A-N fault. The appropriate loop impedance is given by the vector
sum:
 Z1 + Z1 residual = Z1 + (Z1 x kZN Res CompkZN Angle) .
8.4.2.3 Zone 2 reach check
The zo
ne 2 element is set to be directional forward.
Apply a dynamic B-C fault, slightly in excess of the expected reach. The duration of the
injection should be in excess of the tZ2 timer setting, but less than tZ3. Repeat as in 8.4.2.2
to find the zo
ne reach.
Record the impedance at which the relay tripped. The measured impedance should be
within +/- 10% of the expected reach. Read and reset the alarms.
Modern injection test sets usually calculate the expected fault loop impedance from the relay
settings, for those that do not:
Connections for a B-C fault. The reach for phase-phase should be checked and the
operation of the appropriate contacts confirmed. The appropriate loop impedance is now
given by:
2 x Z2 