Oscillography - GE L30 Instruction Manual

5 SETTINGS
disconnected. The method is accurate only if this setting matches perfectly the actual system impedance during the fault. If
the system exhibits too much variability, this approach is questionable and the fault location results for single-line-to-ground
faults shall be trusted with accordingly. It should be kept in mind that grounding points in vicinity of the installation impact
the system zero-sequence impedance (grounded loads, reactors, zig-zag transformers, shunt capacitor banks, etc.).
a) MAIN MENU
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PATH: SETTINGS PRODUCT SETUP
 OSCILLOGRAPHY
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Oscillography records contain waveforms captured at the sampling rate as well as other relay data at the point of trigger.
Oscillography records are triggered by a programmable FlexLogic operand. Multiple oscillography records can be captured
simultaneously.
The is selectable, but the number of cycles captured in a single record varies considerably based on
NUMBER OF RECORDS
other factors, such as sample rate and the number of operational modules. There is a fixed amount of data storage for
oscillography; the more data captured, the less the number of cycles captured per record. See the
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RECORDS

OSCILLOGRAPHY

ple configurations with corresponding cycles/record. The minimum number of oscillographic records is three.
Table 5–9: OSCILLOGRAPHY CYCLES/RECORD EXAMPLE
RECORDS CT/VTS
3 1
3 1
16 1
16 1
32 1
32 1
3 2
3 2
16 2
A new record can automatically overwrite an older record when
Set the to a percentage of the total buffer size (for example, 10%, 50%, 75%, and so on). A trigger posi-
TRIGGER POSITION
tion of 25% consists of 25% pre- and 75% post-trigger data. The
can be any FlexLogic parameter (element state, contact input, virtual output, and so on). The relay sampling rate is 64 sam-
ples per cycle.
GE Multilin

OSCILLOGRAPHY
NUMBER OF RECORDS:
15
TRIGGER MODE:
Automatic Overwrite
TRIGGER POSITION:
50%
TRIGGER SOURCE:
Off
AC INPUT WAVEFORMS:
16 samples/cycle
 DIGITAL CHANNELS
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 ANALOG CHANNELS

menu to view the number of cycles captured per record. The following table provides sam-
SAMPLE DIGITAL
RATE CHANNELS
32 32
64 32
32 32
64 32
32 32
64 32
32 32
64 32
32 32
L30 Line Current Differential System
Range: 1 to 64 in steps of 1
Range: Automatic Overwrite, Protected
Range: 0 to 100% in steps of 1
Range: FlexLogic operand
Range: Off; 8, 16, 32, 64 samples/cycle
ANALOG CYCLES PER
CHANNELS RECORD
16 2399
16 1450
16 666
16 402
16 352
16 213
16 1516
16 851
16 421
is set to "Automatic Overwrite."
TRIGGER MODE
is always captured in oscillography and
TRIGGER SOURCE
5.2 PRODUCT SETUP
5.2.8 OSCILLOGRAPHY
5
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ACTUAL VALUES
5-71