Description
Product Overview
- The rotor earth fault protection relay 50N/51N is suitable for protecting generators with hydro turbine capacities not exceeding 10 MW and steam turbine generator capacities not exceeding 100 MW.
- Together with generator differential protection and generator backup protection, it forms a comprehensive generator protection system. It can be installed in a centralized panel or distributed across multiple locations.
Generator Rotor Grounding Protection Device Technical Specification Table
| Category | Function/Parameter Item | Specification Details |
|---|---|---|
| Protection Configuration | Generator Rotor Grounding Protection | Supports one-point grounding protection and two-point grounding protection for generator rotor |
| Measurement and Control Functions | Analog Signal Measurement | Supports measurement of Ue, Rg, K analog signals |
| Measurement and Control Functions | Digital Input Channels | Configurable with 21 channels of active AC/DC 220 V or DC 110 V digital input (specify when ordering) |
| Measurement and Control Functions | Relay Output Channels | Equipped with 12 protection outputs, 1 signal output, and 1 power failure output |
| Communication Mode | Supported Communication Interfaces & Protocols | Optional: RS-485, CAN bus, Ethernet, IEC 60870-5-103 (IEC-103) |
| Time Synchronization Function | Time Synchronization Modes | 1. Supports communication-based time synchronization, SNTP, and message-based time synchronization
2. Features configurable dedicated B-code time synchronization interface (switchable to use RS-485 port) 3. Supports IRIG-B time synchronization |
| Printing Function | Printer Support & Print Content | Supports serial communication dot-matrix printers; can print setpoints, event logs and other relevant content |
Device storage capacity
- Trip Reports: The device cyclically stores up to 128 latest trip records.
- Operation Log: It cyclically records up to 128 recent operation events.
- Device Self-Test: Up to 32 groups of latest self-test data are saved in cyclic mode.
- Fault Recording: The device cyclically keeps 32 recent fault recording events.
Environmental Conditions
- Operating temperature range: -10°C to 55°C
- Operating temperature range: -40°C to 70°C
- Storage temperature: -40°C to 80°C
- Relative humidity: 5%–90% (no condensation inside the product)
- Altitude: ≤2000 m; for altitudes above 2000 m, adjustments shall be made using the altitude correction factor.
Schematic
Protection Setting Sheet
| No. | Setting Name | Setting Range | Unit | Default Value | Remark |
|---|---|---|---|---|---|
| 1 | One-point Ground Fault Setting | 0.1–100 | kΩ | 10 | Unit: kΩ (kiloohm) |
| 2 | One-point Ground Fault Time Delay | 0–100.00 | s | 5 | Adjustable on-site as required |
| 3 | One-point Ground Fault Mode | 0–2 | — | 2 | 0=Disabled, 1=Trip, 2=Alarm |
| 4 | Two-point Ground Fault Setting | 0.050–0.999 | % | 30% | 0.3, position deviation between one-point and two-point grounding |
| 5 | Two-point Ground Fault Time Delay | 0–100 | s | 2 | |
| 6 | Ground Protection Starting Voltage | 10–500 | V | 50 | Default: 50V; set according to actual excitation voltage |
Dimensions and Cutout Sizes
FAQ
Q:What are the two working principles of the Rotor Earth Fault Protection Relay for generator rotor grounding protection?
A:The principles of generator rotor grounding can be divided into two types: the ping-pong type and the injection type. These two methods must not be used interchangeably.
Q:How is relay protection for generator rotors typically used?
A:Generator rotor ground protection generally serves two functions: single-point ground protection and two-point ground protection. When a single-point ground occurs in the generator rotor, the protection device issues an alarm; when a two-point ground occurs, the protection device trips immediately.
Q:Under what conditions does generator rotor grounding occur?
A:Generator rotor grounding occurs when the rotor winding insulation becomes damaged due to aging, mechanical wear, moisture, overheating or foreign debris, connecting live conductors to the grounded metal rotor shaft.
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Rotor earth fault relay (ANSI 64R) monitors generator rotor winding insulation damage. High measuring precision, adjustable sensitivity and standard communication, widely used for turbo & hydro generators.
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Clear LED indicators provide quick status checks at a glance.