ABB REC 561 User Manual page 233

1MRK 580 169-XEN
Page 5 - 54
Fuse-failure supervision function
voltage-dependent functions must operate. Simulate normal
operating condition again. Disconnect the dc voltage from the
FUSE-MCB binary input terminal.
1.7 Set the operating mode of the FFS function to the Operation =
Zeroseq. Disconnect one of the phase voltages and observe the log-
ical output signals on the terminal binary outputs. FUSE-VTSU and
FUSE-VTSZ signals should simultaneously appear.
1.8 Immediately disconnect the remaining two phase voltages and all
three currents. There should be no change in the statuses of all three
output signals.
1.9 Simultaneously establish normal voltage and current operating con-
ditions and observe the corresponding output signals. They should
change to the logical 0 as follows:
•Signal FUSE-VTF3PH after about 25 ms
•Signal FUSE-VTSU after about 50 ms
•Signal FUSE-VTSZ after about 200 ms
1.10 Slowly decrease the measured voltage in one phase until the FUSE-
VTSU signal appears. Record the measured voltage and calculate
the corresponding zero-sequence voltage according to the equation
(observe that the voltages in the equation are phasors):
⋅
3 U ˆ U ˆ
= +
0 L1
where:
U ˆ U ˆ U ˆ
, and
L1 L2
Compare the result with the set value of the zero-sequence operat-
ing voltage. The result should be within the +5% limits of accuracy
with the addition of declared accuracy for testing equipment.
1.11 Establish normal operating conditions. Set the operating mode of
the FFS function at the Operation = Negativeseq. Repeat the same
procedure as under the Zeroseq mode with the difference that the
measured and set quantities are the negative-sequence voltages and
currents. The corresponding equations are as follows:
⋅
3 U ˆ U ˆ
= +
2 L1
⋅
a ˆ = 1 e
where:
1.12 Disconnect the testing equipment. Don't forget to configure the ter-
minal, if necessary, to its normal operating configuration.
ABB Network Partner AB
U ˆ U ˆ
+
L2 L3
are the measured phase voltages.
L3
2
⋅ ⋅
U ˆ U ˆ
a ˆ + a ˆ
L2 L3
2 π ⋅
j --------- -
3
3
,
------ -
= – 0 5 + j
2
Version 1.0-00