Directional Testing With Load Current - Siemens SIPROTEC 7SJ62 Instruction Manual
Multi-functional protective relay with bay controller
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Also See for SIPROTEC 7SJ62:
- Manual (704 pages) ,
- Technical data manual (58 pages) ,
- Manual (94 pages)
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Installation and Commissioning
Current and
Voltage Values
Phase Rotation
Voltage
Transformer
Test Switches or
Circuit Breakers
8.3.2
Directional Testing With Load Current
Load Current ≥
[10% I
]
N
8-20
a problem, the relevant condition can be viewed in the Event Log. If current summation
errors occur, then check the matching factors. See Sub-section 6.17.2.1.
Messages from the symmetry monitoring could occur because there actually are
asymmetrical conditions in the network. If these asymmetrical conditions are normal
service conditions, the corresponding monitoring functions should be made less sen-
sitive. See Sub-section 6.17.2.1.
Currents and voltages can be seen in the display field on the front of the device under
0HDVXUHPHQW. The quantities can also be viewed under 0HDVXUHPHQW in the
®
DIGSI
4 window. The currents and voltages displayed by the device can be com-
pared to the quantities measured by an independent source.
The actual phase rotation of the voltages must correspond to the setting under Ad-
dress 3+$6( 6(4 in 36\WHP 'DWD; otherwise, an alarm message occurs.
If the alarm occurs, then the phase sequence of the measured quantities should be
checked, and the proper corrections made.
Remove voltage to the device by opening the test switches, fuses, or circuit breaker.
Under the Measurement menu, the voltage readings should be close to zero (minimal
voltage values are insignificant).
If a miniature circuit breaker (MCB) is in the VT circuits and its auxiliary contact is con-
nected to the 7SJ, the corresponding annunciations should be read from the log buff-
ers to verify connections and settings when the MCB is tripped.
When the voltage on the binary input connected to this auxiliary contact is removed,
the message "!)$,/ )(('(5 RU %86 97 21" should appear in the Event Log.
When the voltage is restored, the message "!)$,/ )(('(5 RU %86 97 OFF"
should occur. If one of these messages does not appear, then the connections and
the configuration settings should be checked. If the ON and OFF messages are ex-
changed, then the breaker auxiliary contact type should be checked and corrected if
necessary (refer to Sub-section 5.2).
This test may cause the trip outputs of the 7SJ62 to close. If tripping of primary equip-
ment is undesirable, disconnect the trip contacts of the 7SJ62; however, adequate
backup protection should be available if 7SJ62 tripping is defeated.
The connections of the current and voltage transformers are checked using load cur-
rent on the protected line or equipment. The secondary load current must be at least
[0.10 · I
]. The load current should be in-phase or lagging the voltage (resistive or re-
N
sistive-inductive load). The direction of the load current must be known. If there is a
doubt, network loops should be opened or other action taken to guarantee the direc-
tion of the load current.
The 67-TOC element is used to generate directional messages. The pickup threshold
of 67-TOC, approximately [1.1 · Address ], must be reduced so that the available
load current causes a continuous pickup of the element. The direction reported in the
messages must correspond to the actual power flow. While performing this test and
interpreting the results, be careful that the "Forward" direction of 67-TOC is in the di-
rection of the line (or object to be protected). This is not necessarily identical with the
7SJ62 Manual
C53000-G1140-C121-1
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