English
The Grounding Resistor from RST Electric serves as the cornerstone of safety in medium-voltage electrical systems. When a ground fault occurs in ungrounded or solidly grounded systems, fault currents can reach destructive levels, endangering personnel and damaging transformers, cables, and rotating machinery. This Neutral Earthing Resistor addresses this risk by inserting a carefully calculated resistance between the system neutral and earth, limiting ground fault current to a predetermined value – typically between 10A and 2000A – while still allowing sufficient current for protective relays to detect and isolate the fault.
The construction of this Power System Resistor emphasizes durability and long-term reliability in harsh environments. The resistor elements utilize grid-type design fabricated from high-grade stainless steel (SUS430 and SUS304), selected for their excellent corrosion resistance, stable temperature coefficient, and ability to withstand repeated fault cycles without degradation. These elements are housed within robust enclosures available in SUS304 stainless steel, SUS316 for marine applications, or painted galvanized sheet steel, all designed to provide IP protection appropriate for indoor or outdoor installation.
Electrical performance is validated through rigorous testing: insulation resistance exceeds 100MΩ, and dielectric withstand is verified at levels from 32kV to 95kV for one minute. Basic Impulse Levels (BIL) range from 60kV to 170kV, ensuring the resistor can survive lightning strikes and switching surges. Time ratings from 5 seconds to 60 seconds accommodate various fault clearing scenarios, with the resistor designed to absorb the full fault energy without exceeding temperature limits.
As a trusted Neutral Grounding Resistor manufacturer in China, RST Electric combines over 10 years of power resistor engineering expertise with deep understanding of medium-voltage system protection to deliver components that meet the stringent requirements of utilities, industrial plants, and renewable energy facilities worldwide.
|
Parameter |
Specification |
|
Model |
NGR/NER |
|
Rated System Voltage |
6.3kV – 35kV |
|
Rated Fault Current |
10A – 2000A |
|
Rated Time |
5 seconds – 60 seconds |
|
Resistance Range |
1Ω – 9999Ω (custom values available) |
|
Withstanding Voltage |
32kV – 95kV / 1 minute |
|
Basic Impulse Level (BIL) |
60kV – 170kV |
|
Insulation Resistance |
≥ 100MΩ |
|
Temperature Coefficient (TCR) |
Low TCR design for stability under fault conditions |
|
Resistor Element Type |
Grid type (SUS430 / SUS304 stainless steel) |
|
Enclosure Material |
SUS304, SUS316, or Painted Galvanized Sheet Steel |
|
Mounting |
Outdoor / Indoor floor mount |
|
Termination |
High-voltage bushings / Cable entry |
|
Compliance |
IEEE32, RoHS, CE |
|
Optional Monitoring |
Current transformers, thermal protection, alarm contacts |
1.High Temperature Resistance – Stainless steel grid elements withstand the extreme thermal stress of fault current conditions without deformation or resistance drift.
2.Stable Resistance & Low TCR – Specially selected alloys ensure minimal resistance change during fault cycles, maintaining accurate current limitation.
3.Robust & Durable Construction – Heavy-duty enclosures and grid assemblies designed for decades of service in utility and industrial environments.
4.Integrated Monitoring Options – Available with current transformers, thermal sensors, and alarm contacts for remote status indication.
5.Standard Compliance (IEEE32) – Designed and tested to meet IEEE32 requirements for neutral grounding devices, ensuring reliable performance.
6.Wide Voltage & Current Range – From 6.3kV to 35kV and 10A to 2000A, covering diverse applications from small industrial generators to large substations.
7.Flexible Time Ratings – Available from 5 seconds to 60 seconds to match specific protection schemes and fault clearing times.
8.Corrosion-Resistant Enclosures – SUS304, SUS316, or painted galvanized steel options for indoor, outdoor, or marine environments.
9.High Insulation & BIL Levels – Withstanding voltages to 95kV and BIL to 170kV ensure survival of lightning strikes and switching surges.
10.Custom Design Capability – Special voltage ratings, resistance values, enclosure configurations, and monitoring packages available
|
Industry |
Specific Application |
Description |
|
Power Generation |
Generator Neutral Grounding |
Limits fault currents in generator windings, protecting the stator from damage during ground faults . |
|
Transformer Grounding |
Provides neutral grounding for step-up and station service transformers in power plants . |
|
|
Industrial & Mining |
Medium-Voltage Distribution |
Grounding for 6.6kV to 36kV industrial power systems in mines, factories, and processing plants . |
|
Motor Grounding |
Protects large medium-voltage motors from damage during ground faults . |
|
|
Marine & Offshore |
Shipboard Power Systems |
Corrosion-resistant NGRs for vessel electrical systems requiring saltwater environment durability . |
|
Platform Electrical Networks |
Grounding for offshore oil and gas platform power distribution . |
|
|
Renewable Energy |
Wind Farm Substations |
Neutral grounding for collector system transformers in wind power plants . |
|
Solar Farm Inverters |
Grounding for medium-voltage inverters and step-up transformers in PV installations . |
|
|
Utilities |
Substation Grounding |
Distribution and transmission substation neutral grounding for fault current control . |
|
Urban Power Networks |
Grounding for underground cable distribution systems in cities . |
|
Spec |
L(mm) |
W(mm) |
H(mm) |
Weight(KG) |
|
6.3&10kv-10~200A |
800 |
800 |
2200 |
300 |
|
10kv-400A |
1000 |
1000 |
1800 |
400 |
|
10kv-800A |
1200 |
1200 |
1800 |
600 |
|
10kv-1000A |
1200 |
1200 |
2200 |
700 |
|
21KV-300A |
1000 |
1000 |
1800 |
500 |
|
35KV-200A |
1600 |
2400 |
2200 |
1200 |
|
35KV-400A |
1800 |
1500 |
2300 |
1300 |
RST Electric ensures safe delivery of every Neutral Grounding Resistor:
● Heavy-Duty Crating: Each NGR is securely mounted on a reinforced steel skid and enclosed in a custom plywood crate designed for international shipping.
● Weather Protection: Units are wrapped in waterproof VCI film with desiccant packs to prevent moisture ingress during sea freight.
● Lifting Provisions: Clear labeling of lifting points and center of gravity; shipping brackets included for secure tie-down.
● Terminal Protection: High-voltage bushings are protected with weather caps during transit.
● Documentation: Comprehensive shipping documents include packing lists, certified test reports, material certifications, and customs clearance support.
● Freight Options: We coordinate with specialized heavy-lift freight forwarders for FCL sea freight, project cargo, or air freight as required.
All units undergo full factory acceptance testing (FAT) including resistance measurement, insulation resistance, dielectric withstand, and visual inspection before packaging.
When system protection demands uncompromising quality, RST Electric delivers.
● We are a certified Manufacturer based in China, specializing in Neutral Grounding Resistor production for over 10 years.
● Complete in-house control over grid element fabrication, enclosure manufacturing, assembly, and testing – ensuring consistent quality.
● Factory-direct pricing on every NGR, with transparent cost structure and no middlemen.
● ISO 9001 certified facilities with dedicated production lines for stainless steel grid resistors.
● 100% electrical testing (resistance, insulation, dielectric, BIL sample testing) performed on every unit.
● Thermal imaging validation ensures even heat distribution during fault simulation.
● Experienced engineering team specializing in medium-voltage system protection and IEEE32 compliance.
● Proven Supplier to utility companies, EPC firms, mining operators, and renewable energy developers worldwide.
● Export track record to over 40 countries, including USA, Canada, Australia, Germany, Saudi Arabia, and Singapore.
● Deep domain expertise in neutral grounding applications across power generation, distribution, and industrial sectors.
● System voltages: 6.3kV to 35kV (higher available with custom design).
● Fault currents: 10A to 2000A (special ratings available).
● Time ratings: 5 seconds to 60 seconds (custom durations available).
● Resistance values: 1Ω to 9999Ω (calculated per application).
● Enclosure materials: SUS304 / SUS316 / Painted steel / Custom.
● Monitoring options: CTs / Thermal sensors / Alarm contacts / Remote monitoring.
● Terminations: High-voltage bushings / Cable boxes / Custom.
● Standard lead time: 15-20 days for standard ratings; 20-25 days for customization.
● Comprehensive documentation: Test reports, material certifications, IEEE32 compliance statements, CE declarations.
● 12-month warranty with remote troubleshooting and spare parts dispatch.
● Technical support available for system integration, relay coordination, and on-site commissioning.
Address
No. 13, North Shore Road, Huangjiang Town, Dongguan City, Guangdong Province, China
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