Alstom MiCOM P546 - 8.3.1.3 Upper slope

Commissioning P54x/EN CM/La4
MiCOM P543, P544, P545 & P546
CM) 10-39
CM
(NOTE: 1pu = 1A into terminals C3-C2 for 1 A applications; or 1 pu = 5 A into terminals
C1-C2 for 5 A applications). The relay will trip and any contacts associated with the A-phase
will operate, and bit 1 (rightmost) of [0F03: Test Port Status] will be set to 1. Some LEDs,
including the yellow alarm LED, will go off, but ignore them for the moment.
When the current in A Phase is established, close the switch and slowly increase the current
in the B phase from zero until Phase B trips (bit 2 of [0F03: Test Port Status] is set to 1).
Record the phase B current magnitude and check that it corresponds to the information
overleaf.
Switch OFF the ac supply, read and clear all alarms.
Bias current
Differential
current
Phase Magnitude Phase
Magnitude of differential current
2 Terminal & Dual
Redundant
0.25 pu +/-10%
A 1pu B
3 Terminal 0.216 pu +/-10%
Assumption: 
s1
= 0.2 pu, k
1
= 30%, 
s2
= 2.0 pu
For other differential settings or current injected into A phase (I
a
), the formula below can be
used (enter slope in pu form, i.e. percentage/100):
2 Terminal & Dual Redundant:
B phase operate current is 0.5 x [
s1
+ [I
a
x k
1
)] pu +/- 10% -
3 Terminal:
B phase operate current is 0.333 x [
s1
+ (1.5 x I
a
x k
1
)] pu +/- 10% -
Ensure that I
a
< I
S2
8.3.1.3 Upper slope
Rep
eat the test in 8.3.1.2 with the bias current set in the A-phase to be 3pu.
When the current in A Phase is established, close the switch and slowly increase the current
in the B phase from zero until phase B trips (bit 2 of [0F03: Test Port Status] is set to 1).
Record the phase B current magnitude and check that it corresponds to the information
below.
Switch OFF the ac supply and reset the alarms.
Bias current
Differential
current
Magnitude of differential current
Phase Magnitude Phase k
2
150% 1.15pu +/-10%
2 Terminal & Dual
Redundant
100% 0.9pu +/-10%
150% 1.51pu +/-10%
A 3pu B
3 Terminal
100% 1.1pu +/-10%
Assumption: 
s1
= 0.2pu, k
1
= 30%, 
s2
= 2.0pu, k
2
as above