Description
Product Overview
- Small Current Grounding Line Selection relies on the grounding line selecting device to identify single-phase ground faults in power systems with ungrounded neutral, resistor grounded neutral or arc-suppression coil grounded neutral.
- Widely used in power plants, substations, and the power supply systems of large industrial and mining enterprises for single-phase ground fault alarm on lines and busbars, or for line ground fault protection tripping.
Small Current Grounding Line SelectionFeatures
Ground Selection Function
- Transient route selection method;
- Zero-sequence overcurrent directional selection method;
- PT de-resonance and PT open-circuit monitoring;
- Reclosing function;
- Acceleration protection after overlap;
Device self-test function
- The device automatically detects faults such as RAM, FLASH, A/D, and power loss;
- Automatically detect parameters such as setpoints, configurations, and coefficients.
Communication Features
- The device supports three communication modes: RS-485, RS-232, Ethernet, and IEC 61850 (please specify when ordering);
- The device uploads real-time data, including busbar voltage, current, grounding information, harmonic data, and other relevant data;
- Receive control commands issued by higher-level systems, including remote control and system synchronization.
Panel Display Features
- The panel features a Chinese character LCD display, status indicator lights, and a keypad, making it easy to monitor measurement tracking.
Time synchronization function
- Supports network-based time synchronization via communication channels;
- Supports IRIG-B code synchronization;
Rated Electrical Parameters
Power supply
- Rated operating voltage: AC/DC 220 V;
- Permissible deviation: -20% to +15%;
- Ripple factor: not more than 5%.
AC circuit
- AC current In: 1 A/5 A;
- AC voltage Un: 100 V;
- Frequency: 50 Hz.
Power consumption
- DC power circuit: During normal operation, no more than 25 VA; when the device is activated, no more than 30 VA.
- AC voltage circuit: When the rated voltage is 100 V, no more than 1 VA per phase;
- AC current circuit: When the rated current is 1 A, no more than 0.5 VA per phase; when the rated current is 5 A, no more than 1 VA per phase.
How It Works
- When a single-phase-to-ground fault occurs in a low-current system, the transient current distribution is characterized by the following: the zero-sequence current in the faulted line has the maximum amplitude and is equal to the sum of the zero-sequence currents in the other, non-faulty lines.
- The Small current grounding line selecting device uses the concept of relative phase—specifically, the direction of the currents relative to one another or the leading and lagging relationships between current and voltage—to determine whether the fault is on the busbar or on the line;
- In the event of a line fault, the system accurately identifies the faulty line. Since the system operates on the principle of relativity, it overcomes the effects of changes in operating modes, ground resistance, and line length, and requires no calibration.
Small current grounding line selecting device Mechanical Installation Dimensions Drawing
- Dimensions: Width × Height × Depth = 484 × 177 × 285 (mm)
- Mounting hole dimensions: 445 × 177 (with 4 mounting holes, each 6.5 mm in diameter)
Fixed-Price Order
| No. | Display Name | Range | Step | Remark |
|---|---|---|---|---|
| 1 | Bus Setting | Bus I setting
Bus II / Bus III / Bus IV are consistent with Bus I |
||
| 1.1 | Name | M001~M004 | 1 | |
| 1.2 | PT Ratio | 1-1000 | — | |
| 1.3 | PT Disconnection | Enable / Disable | — | |
| 1.4 | Outlet Quantity | — | — | |
| 1.5 | Earth Fault Trip | Enable / Disable | — | Enable for trip, Disable for alarm |
| 1.6 | Earth Fault Time Delay | 0.1S | 0.1S | |
| 1.7 | Post Acceleration | Enable / Disable | — | Need to set acceleration time if enabled |
| 1.8 | Earth Fault Voltage | 5.0～100.0V | 0.1V | |
| 1.9 | Rotation Control | Enable / Disable | — | |
| 1.10 | Voltage Threshold | 0.1～100.0V | 0.1V | |
| 1.11 | Voltage Dead Zone | 0.1～100.0V | 0.1V | |
| 1.12 | Rotation Mode | Auto / Fixed | — | Auto rotation mode / Fixed rotation mode |
| 1.13 | Rotation Time Delay | 0.1S | 0.1S | |
| 1.14 | PT Blocking Earth Protection | Enable / Disable | — | Block earth protection when PT disconnection occurs |
| 1.15 | Rotation Voltage | 5.0～100.0V | 0.1V | |
| 1.16 | Corresponding Bus Number | 1-4 | — | |
| 1.17 | Permanent Fault Time Delay | 0～100.0S | 0.1S | |
| 1.18 | Spare | Enable / Disable | — | |
| 1.19 | Current Threshold | 5～100mA | 1mA | |
| 1.20 | Spare | Enable / Disable | — | |
| 1.21 | Current Dead Zone | 5～100mA | 1mA | |
| 1.22 | Spare | Enable / Disable | — | |
| 1.23 | Spare | Enable / Disable | — | |
| 2 | Feeder Setting | Feeder No.01
Other feeders follow the same setting |
||
| 2.1 | Name | Line I B001 | — | |
| 2.2 | Line Type | Overhead / Cable / Station Internal | — | |
| 2.3 | Line Trip Output No. | — | — | |
| 2.4 | CT Ratio | 1～1000 | — | |
| 2.5 | CT Polarity | Positive / Reverse | — | |
| 2.6 | Transient Earth Fault Setting | 5～100mA | 1mA | |
| 2.7 | Earth Delay High Byte | 0～100.0S | 0.1S | |
| 2.8 | Line Earth Fault Trip | Enable / Disable | — | Trip when enabled, alarm when disabled |
| 2.9 | Earth Fault Current | 5～100mA | 1mA | |
| 2.10 | Spare | — | — | |
| 2.11 | Earth Delay Low Byte | 0～100.0S | 0.1S | |
| 2.12 | Rotation Control | Enable / Disable | — | Participate in rotation if enabled |
| 2.13 | Rotation Sequence | 1-4 | — | |
| 2.14 | Line Closing Output No. | — | — | |
| 2.15 | Auto-reclosing Enable | 0 / 1 | — | |
| 2.16 | Protection Trigger Reclosing | 0 / 1 | — | |
| 2.17 | Reclosing Time Delay | 0～100.0S | 0.1S | |
| 3 | Spare Setting | — | — | |
| 4 | Resonance Threshold Setting | |||
| 4.1 | Spare | 5.0～100.0V | 0.1V | |
| 4.2 | Spare | 5.0～100.0V | 0.1V | |
| 4.3 | 17Hz Resonance Threshold | 5.0～100.0V | 0.1V | |
| 4.4 | 25Hz Resonance Threshold | 5.0～100.0V | 0.1V | |
| 4.5 | 50Hz Resonance Threshold | 5.0～100.0V | 0.1V | |
| 4.6 | 150Hz Resonance Threshold | 5.0～100.0V | 0.1V | |
| 4.7 | 250Hz Resonance Threshold | 5.0～100.0V | 0.1V | |
| 4.8 | Overvoltage Threshold | 5.0～100.0V | 0.1V | |
| 5 | Binary Input Setting | |||
| 5.1 | Debounce Time Delay | 10ms～9999ms | — | Factory default: 20ms |
| Remote Signal Polarity 1～48 | 0 or 1 | — | ||
| 6 | LCD Setting | |||
| 6.1 | Fault Lamp Reset Mode | Auto / Manual | — | |
| 6.2 | Fault Lamp Return Time | 0～120S | 1s |
FAQ
Q：What are the common technical parameters to consider when selecting a low-current ground fault line identification device?
A:To summarize, when selecting a low-current ground fault detection device, the common reference parameters include: first, the number of control circuits, which should be determined based on actual conditions; second, whether it has a trip function; and third, whether it has a fault recording function.
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