NEUTRAL GROUNDING RESISTORS
Where continuity of service is a high priority, high-resistance grounding provides the safety benefits of a grounded system while minimizing the risk of service interruptions caused by ground faults. The concept is simple: provide a path for ground current through a resistance that limits the current magnitude and continuously monitor the system to determine when an abnormal condition exists. This provides maximum continuity of service because no tripping occurs for resistance-limited ground faults.
The ground current path is provided at the point where the service begins by placing resistance in the connection between the system neutral and ground. Control equipment continuously measures the ground current, and a relay detects when the current exceeds a predetermined level. An alarm alerts building personnel when a ground fault is detected. The system has built-in fault-tracing facilities to assist in locating the source of the ground fault. An integral transformer provides control power from the primary source.
The pulser circuit provides a convenient method to locate the faulted feeder and trace the fault to its origin. The pulser is available whenever a fault has been detected. The pulse intervals are controlled by an adjustable recycle timer. The "Pulse" light flashes ON and OFF, corresponding to the ON/OFF cycles of the pulser contactor.
The pulser contactor switches a bank of resistors ON and OFF, allowing a momentary increase in ground current, typically approximately 5A above the existing ground current.
The current pulses can be detected using a clamp-on ammeter placed around the cables or conduit feeding the fault. The operator tests each conduit or set of cables until the pulsing current is detected. By moving the ammeter along the conduit or checking the conduit periodically along its length, the fault can be traced to its origin. The fault may be located at the point where the pulsing current drops off or stops.
Application - Neutral Grounding of LV System
Usage - Other (Oil Industry)
Resistance - As per customer requirement/as per calculations
Brand - National Resistors
Part Number - NA
Mounting Type - Through Hole
Wattage - As per customer requirement/as per calculations
Country of Origin - India
Shape - Other (As per Customer Requirement)
Max. Power Dissipation - As per design/customer rating
Max. Resistance - As per design/customer rating
Size - As per design/customer rating
Max. Overload Voltage - 10%
Max. Current Rating - As per customer requirement/as per calculations
Weight - As per design/customer rating
Warranty - 12 months from commissioning or 18 months from supply, whichever is earlier
Minimum Order Quantity - 1 No.
Production Capacity - 25 Nos./Month
Product/Service Code -
Delivery Time - 8 weeks from Manufacturing Clearance
Packaging Details - Indian Roadworthy Packing / Export Seaworthy Packing
SPECIFICATIONS
NGR WITH PULSATING CIRCUIT
DESCRIPTION
22KV NGR PANEL
SPECIFICATIONS
Neutral Grounding Resistors (NGRs) are designed to limit fault current and enhance the safety of equipment and personnel in industrial electrical systems.
NGR systems are connected between the system neutral and ground to provide ground-fault protection through controlled resistance. The primary purpose of a Neutral Grounding Resistor (NGR) is to limit ground-fault current to safe levels, enabling sensitive and selective earth-fault protection relays to operate effectively while protecting electrical equipment throughout the power system.
Neutral Grounding Resistors are also commonly known as Neutral Earthing Resistors and Earth Fault Protection Resistors.
Technical Specifications
• Operating Voltage - 22 kV Line-to-Line System
• Rated Current - Up to 5000A
• Ambient Temperature - Up to 50°C (For higher ambient temperatures, consult the factory)
• Resistance Alloy - Stainless Steel (AISI-304), AISI-430 FeCrAl, Cu-Ni, Ni-Cr, Cast Iron
• Protection Degree - IP33 (Outdoor) and others on demand
• Standards - IEEE 32, IEC 60529
Application - Neutral Grounding of Transformer/Generator
Material - AISI 304 / AISI 430 / AISI 410
Surface Treatment - B2B
Thickness - As per customer rating
Washers - Mica
Zinc Coating - ---
Usage - Other (Mines, Steel Industry, Power Plants, Substations, Transformers, Generators)
Resistance - As per customer requirement/as per calculations
Brand - National Resistors
Part Number - NA
Mounting Type - Through Hole
Wattage - As per customer requirement/as per calculations
Country of Origin - India
Shape - Other (Rod, Sheet)
Max. Power Dissipation - As per design/customer rating
Max. Resistance - As per design/customer rating
Size - As per design/customer rating
Max. Overload Voltage - 10%
Max. Current Rating - As per customer requirement/as per calculations
Weight - As per design/customer rating
Warranty - 12 months from commissioning or 18 months from supply, whichever is earlier
Range - 22 kV
Minimum Order Quantity - 1 No.
Production Capacity - 25 Nos./Month
Product/Service Code -
Delivery Time - 8 weeks from manufacturing clearance
Packaging Details - Indian Roadworthy Packing / Export Seaworthy Packing
DESCRIPTION
33KV NGR PANEL
SPECIFICATIONS
Neutral Grounding Resistors (NGRs) are designed to limit fault current and enhance the safety of equipment and personnel in industrial electrical systems.
Neutral Grounding Resistor systems are connected between the system neutral and ground to provide ground-fault protection through controlled resistance. The fundamental purpose of a Neutral Grounding Resistor (NGR) is to limit ground-fault currents to safe levels, allowing sensitive and selective earth-fault protection relays to operate effectively while protecting electrical equipment throughout the power system.
Neutral Grounding Resistors are also commonly referred to as Neutral Earthing Resistors and Earth Fault Protection Resistors.
Technical Specifications
• Operating Voltage - 33 kV Line-to-Line System
• Rated Current - Up to 2000A
• Ambient Temperature - Up to 50°C (For higher ambient temperatures, consult the factory)
• Resistance Alloy - Stainless Steel (AISI-304), AISI-430 FeCrAl, Cu-Ni, Ni-Cr, Cast Iron
• Protection Degree - IP33 (Outdoor) and others on demand
• Standards - IEEE 32, IEC 60529
Application - Neutral Grounding of Transformer/Generator
Material - AISI-304 / AISI-430 / AISI-410
Surface Treatment - B2B
Thickness - As per customer rating
Washers - Mica
Zinc Coating - ---
Usage - Other (Mines, Steel Industry, Power Plants, Substations, Transformer, Generators)
Resistance - As per customer requirement/as per calculations
Brand - National Resistors
Part Number - NA
Mounting Type - Through Hole
Wattage - As per customer requirement/as per calculations
Country of Origin - India
Shape - Other (Rod, Sheet, Wire)
Max. Power Dissipation - As per design/customer rating
Max. Resistance - As per design/customer rating
Size - As per design/customer rating
Max. Overload Voltage - 10%
Max. Current Rating - As per customer requirement/as per calculations
Weight - As per design/customer rating
Warranty - 12 months from commissioning or 18 months from supply, whichever is earlier
Range - 33kV
Minimum Order Quantity - 1 No.
Production Capacity - 25 Nos./Month
Product/Service Code -
Delivery Time - 10 weeks from Manufacturing Clearance
Packaging Details - Indian Roadworthy Packing / Export Seaworthy Packing