FUNCTION

Neutral Grounding Resistors are used to protect power transformers, power generators, and other associated equipment in your power systems against 50/60 Hz faults (short circuit) and transient phenomena (lightning).

SPECIFICATIONS

There are three parameters needed to specify the neutral grounding resistor:

  • Rated voltage line to neutral or system voltage
  • Rated fault current
  • Rated “time on” of the line to neutral voltage not exceeding the allowable temperature rise.

RANGE

  •  Rated current: from 1 amp to 5000 A
  • Rated voltage: from 0.38 to 34.5kV
  • Rated time: 1 sec to continuous time rating

TESTING AND QUALITY

All Filnor Neutral Grounding Resistors are designed, rated, manufactured, and tested in strict compliance with IEEE-32.

Routine tests performed on each Neutral Grounding Resistor are measurement of resistance, high voltage power frequency, insulation measurement, aspect verification, dimensional control.

Filnor’s internal quality system has been developed and certified under ISO 9001 quality system.

CONSTRUCTION

A standard unit includes the stainless steel resistor assembly, the required insulators, internal connections and hardware installed in a standard safety enclosure.

Neutral Grounding Resistor units are completely assembled, pre-wired, and tested at our facility. For shipping all units are crated for added protection and ease of handling.

ENCLOSURE FEATURES

  • Solid overhung top slightly sloped to prevent standing water and will support heavy ice and snow.
  • Forged eyebolts in all four corners for easy hoisting.
  • Removable front and rear louvered covers for easy access for connection and inspection.
  • Corrosion resistant nameplate provides complete ratings and manufacturers information.
  • Mill galvanized finish provides maximum protection.
  • Bottom screening prevents the entry of birds and rodents while providing maximum cooling for the resistors.

ENCLOSURE OPTIONS

  •  Mill galvanized, aluminum, stainless steel and hot-dipped galvanized construction. Custom paint finish is available.
  • Top or side mounted entrance bushing(s).
  • Screened covers for indoor applications.
  • Support stands for elevating the enclosure above ground.

OPTIONS

  • Current or potential transformers mounted and prewired at our facility
  • ON or OFF Load disconnecting switches
  • Space heater with thermal switch
  • Specially designed units for hazardous or high altitude locations

Standard Units:

  • Designed and Tested to IEEE-32 Standard
  • Space for Current Transformer
  • Enclosure: Nema 3R Outdoor Mill Galvinized Finish
  • Internal Terminal Connections

Examples of Our Work:

  • FNG20000-200-10 Neutral Grounding Resistor
    • 20000 Volt System
    • 11600 Volt Line to Neutral
    • 200 Ampere
    • 10 Second
    • 200:5 CT Option with Dust Filters and Side Neutral Bushing
  • FNG13800-50-10 Neutral Grounding Resistor
    • 13800 Volt System
    • 8000 Volt Line to Neutral
    • 50 Ampere
    • 10 Second
    • 50:1 CT Option
  • FNG4160-25-C Neutral Grounding Resistor
    • 4160 Volt System
    • 2400 V Line to Neutral
    • 25 Ampere
    • Continuous
    • 200:5 CT Option with Support Stand
  • FNG4160-800-10 Neutral Grounding Resistor
    • 4160 Volt System
    • 2400 Volt Line to Neutral
    • 800 Ampere
    • 10 Seconds
  • High Resistance Neutral Grounding Detection System
    • 480 Volt AC
    • 5 Ampere Maximum
  • FNG13800-400-10 Neutral Grounding Resistor
    • 13800 Volt System
    • 8000 Volt Line to Neutral
    • 400 Ampere
    • 10 Second, with Zig Zag Transformer
    • Severe Weather Enclosure
  • Neutral Grounding Resistor
    • 13.8kV System
    • 8kV Line to Neutral
    • 400 Ampere
    • 10 Second, with Side Neutral & Ground Bushings
  • REQUIRED FOR NEUTRAL GROUNDING RESISTORS
    • Rated voltage line to neutral or system voltage
    • Rated fault current
    • Rated “time on” of the line to neutral voltage
    • Enclosure type (NEMA 1 or NEMA 3R)