Calculated Ground Fault
Description
The ground current is an imbalanced current flowing through the neutral of the three-phase system. In normal conditions, the ground current is negligible or null. It is present only when a ground fault occurs.
 DANGER |
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IMPROPER TRIP DETECTION
Failure to follow these instructions will result in death or serious injury.
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The ground current is calculated internally by the LTMTCT/LTMTCTV sensor module. The calculated ground fault protection function generates the following signals:
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Alarm: Calculated ground current goes above the alarm level.
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Trip: Calculated ground current goes above the pickup level for the specified time delay.
The protection function can be disabled when the motor is in Start state, to avoid nuisance tripping.
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Calculated ground fault protection is not applicable in single-phase mode.
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Hysteresis is not applicable for calculated ground current by setting less than 10% of FLC.
Parameter Setting
The calculated ground fault protection function has the following configurable settings:
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Parameter |
Setting range |
Default value |
|---|---|---|
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Function |
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Trip |
|
Pickup |
10–500% of IFLC in step of 1% |
20% of IFLC |
|
Time Delay |
0.05–600.00 s in step of 0.01 s |
0.2 s |
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Alarm Level |
10–500% of IFLC in step of 1% |
20% of IFLC |
|
Reset Mode |
|
DI + Reset Key |
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Auto-Reset Delay (applicable only if Reset mode is Auto) |
0–6000.0 s in step of 0.1 s |
0.0 s |
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Function While Motor Starting |
|
Disable |