JDR Neutral Grounding Resistance Box Instructions

Add time:

2018-03-21 10:02

Product Description:

In order to prevent and reduce the overvoltage caused by sudden single-phase grounding, intermittent arc grounding, system operation, and system resonance in the power supply network below 35kV of the three-phase three-wire system, resistance grounding is the most effective method at the neutral point of the power supply network, which can eliminate over-voltage hazards to generators, transformers, and other electrical equipment, increase the sensitivity of ground protection, and can selectively and automatically remove ground fault lines in a short period of time.

In order to meet the needs of development, we have developed a variety of specifications of neutral grounding resistance boxes for the electric power system, which feature high quality, beautiful appearance, good ventilation and heat dissipation, splash-proof and moisture-proof, and can meet the needs of customers.

I. Environmental Conditions for Product Use

1. The altitude does not exceed 2000 m

2. Ambient Temperature: -40°C to +50°C

3. Relative Humidity: The ambient humidity can reach 90% at 20±5°C

4. Installation Site: Indoor and outdoor

Product Technical Performance

1. Neutral Point Rated Grounding Resistance

Re= (Ue/ ×Ie) ×103

Re: Neutral Grounding Resistance (Ω)

Ue: Grid Rated Voltage (35 KV, 22 KV, 10 KV, 6.3 KV, 0.4 KV)

Ue: Neutral Point Rated Current (A)

2. The maximum withstand voltage of the resistor is 1.15 times Ue/KV

3. Resistance Error ≤ ±5% (Ambient Temperature 20±5°C)

4. Resistance Temperature Rise ≤ 380°C

5. Withstand Ground Current Duration: Allow long-term operation at10A and below, and 10s at 10-400A

6. Insulation Level: Power Frequency Withstand Voltage 35KV class 42 KV / min

22KV class 42 KV / min

10KV class 42 KV / min

6.3KV 32 KV / min

0.4KV level 3 KV / min

7. Box Protection Class: Indoor IP30 Outdoor IP54

8. According to the user’s needs, linear signals acquiring ground current can be provided in the box. The sampling signal can be:

Current 0～5 A, voltage 0～100 V

9. The incoming line of the medium voltage resistance box can be divided into various ways: upper in and lower out, lower in and lower out, and side in and lower out.

10. Material: Nichrome Ni80Cr20

Product Application Scope

1. City distribution network with cable circuit mainly within 0.4~35KV

2. Power distribution network systems such as power plants, power stations, airports, ports, subways, and large industrial and mining enterprises

3. Power plant distribution system

4. Neutral grounding resistance of large generators

Product Standards

DL/T620-1997 Overvoltage Protection and Insulation Coordination of AC Electrical Installations

DL/T780-2001 Distribution System Neutral Grounding Resistor

GB/T16927-1997 High Voltage Test Technology

GB/11.1-1997 Insulation Coordination of High-Voltage Transmission and Transformation Equipment

GB4208-93 Housing Protection Grade