Grounding Resistance Cabinet

   In the 6-35KV AC power network of China's power system, the neutral point of the power network can be grounded without grounding, through arc suppression coil grounding, high resistance grounding, low resistance grounding and so on. In power systems (especially in urban power supply systems with cable as the main transmission line), large capacitive currents in grounding may create specific "critical" conditions for the occurrence of "intermittent" arc grounding overvoltage, which leads to the generation of arc grounding overvoltage. The application of the neutral resistance grounding method makes the energy (charge) in the power grid capacitor form a discharge channel to the ground, and incharges the resistive current to the fault point, so that the fault current shows the resistance capacitance characteristic, reduces the phase Angle difference with the voltage, reduces the reignition rate after the fault point current crosses the zero arc, and breaks the "critical" condition of arc overvoltage. The overvoltage is limited to 2.6 times the phase voltage. At the same time, it ensures the accurate judgment and elimination of the primary and secondary faults of the feeder line of the high-sensitivity grounding fault protection equipment, so as to effectively protect the normal operation of the system.

  After grounding through resistance, the system can limit the fault current and achieve the following protection：

1. Reduce the burning and melting accidents of malfunction electrical equipment.

2. When the fault current passes through the circuit and device, cut down the mechanical power.

3. Reduce the electrical vibrations and damage to personnel that caused by stray currents in the grounding return path .

4. Reduce impact and flashover injuries to individuals when someone by chance to be at the trouble spot.

5. Reduce and eliminate the instantaneous voltage drop caused by grounding faults.

6. Guarantee control of instantaneous overvoltage.

The NR-BNR type transformer neutral point grounding resistance cabinet is used for the neutral point of transformers in 6~35kV AC power grids and realize the neutral point grounding through resistance in these power grids.

1. Altitude: no more than 5000 meters.

2. Environmental temperature: -40 ℃ -60 ℃.

3. Relative humidity: not more than 95% (25 ℃).

4. Installation place: The air should not contain chemical corrosive gases and vapors, and should not have explosive dust.

5. Grid frequency: 48-52 Hz (50 Hz system), 58-62 Hz (60 Hz system).

6. Apply for indoor and outdoor use.

1. The material of the resistance cabinet body is adopted aluminum zinc coated plate, stainless steel plate or cold-rolled steel plate,

and the appearance is aesthetic, strong corrosion resistance, and protection level achieve to IP 56.

As need as different working conditions, resistance cabinets are split into indoor and outdoor types. 

2. This formula can be useful for upper in- lower out and lower in- lower out, etc. When using upper in -lower out, the top of the cabinet body equipped with wall sleeves, the bottom of the cabinet body  equipped with hanging bars for easy hoisting.

3. The resistance material is adopt alloy material.

Stainless steel or nickel chromium alloy materials which have high electrical conductivity, high temperature resistance, and maximum operating temperature can get to 1570 ℃. And have low temperature coefficient, stable resistance, corrosion resistance, flame , explosion resistance ,and high reliability characters. According to different customer requirements, our company can adopt inlet resistor materials  from British A B company,AVR, PGR company in the United States, or I-Gard company in Canada to make a product.

4.The NR-BNR type neutral point grounding resistance cabinet is a standard product ,it can connected to resistors or electrical components. Anti parallel operation provides convenience for the gradual expansion of the power grid, which requires a gradually reduce in grounding resistance.

5. When the transformer winding is a triangular connection and requires independent installation of Z-type winding grounding transformer. When using a voltage regulator, the NR - BNR type neutral point grounding resistance cabinet can use in conjunction with it.

6. The traditional ground resistance cabinet is only a pure hardware protection device in the intelligent control part. Our company has increased the intelligent control part according to the market demand.

  The device is based on industrial single-chip microcomputer platform, and the software uses C language and assembly language.

Language mixed programming, display large LCD Chinese characters in the display section. The intelligent controller works properly. It can monitor the unbalanced current of neutral points, resistance and resistance cabinet temperature, single phase. When a grounding fault occurs, you can record the current of the grounding line, grounding time, and resistance board.

   Check the temperature change and grounding operation of the resistance cabinet, as well as reserved communication ports. The measured and recorded information is transmitted to the main control room so that the operator can obtain the information in time to complete the relevant information.

Various resistors can be designed and manufactured according to user requirements, with resistance values ranging from 1 Q-1000 Ω and allowable current flow of 1 A-2000 A. The design error of the resistance value is ± 3%, and the allowable flow time is10S, 15S, 30S, 60S, 2h.

Hot Tags: grounding resistance cabinet, China grounding resistance cabinet manufacturers, suppliers, factory, grounding resistance cabinet