Filnor has been one of Americas leading specialists in the design, manufacture and supply of high quality resistor products since 1970 and is ISO9001 certified.

Their products encompass a variety of areas including Load Banks, Neutral Grounding systems, Disconnect Switches, Motion & Crane controls, Harmonic Filters & Damping Resistors, and Dynamic Braking resistors.  

Do you have any faults?..........Let Filnor furnish your Neutral Grounding or Harmonic protection! We have the quality and pricing you can not RESIST OR be without!


Filnor specializes in Neutral Grounding Resistors.


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). All Filnor Neutral Grounding Resistors are designed, rated, manufactured and tested in strict compliance with IEEE-32. They have been at the forefront of innovative resistor design and have built a solid reputation as a high  quality manufacturer of durable, competitively priced resistors for the power generation industry.  In addition to their standard line resistors, they have a large engineering department of experienced resistor designers, which can provide custom engineered units to meet your specific requirements.



Load Bank

Neutral Grounding Resistor

Special Neutral Grounding

DC Crane Resistors Harmonic Filter Harmonic Resistor


Filnor offers a full range of quality products, designed to meet virtually all your power resistor needs.  Their experience and expertise allows them to meet the differing needs of the international market place with custom made resistors at competitive prices, and quick turnaround times. The maximum power ratings specified are for resistors mounted in an open air atmosphere. If units are to be mounted closer together or in a restricted ventilation condition, the maximum power rating should be derated as follows. Resistors in a well ventilated enclosure should be rated at approximately 82% and in and unventilated enclosure at approximately 67% of their maximum power rating.


Bolted Pressure Contact, Medium Voltage, High Current, & Knife Disconnect Switches are designed for ease of operation, low maintenance, dependability, and safety.  They manufacturer economical switches for many industries including utility, telecommunications, marine, mining, chemical, transit, and construction. A large variety of manual, pneumatic, and electrical Switches are available and produced in house.

Typical Applications: Generator, Battery, or Rectifier Disconnects, Transfer Switches, UPS Systems, Crane Rail Isolation, Transit Third Rail Disconnects, and other applications. 

Switch Capabilities:  Bolted Pressure Contact Switches, Grounding Switches, Hook Stick Switches, Knife Switches, Special Design Switches, Transfer Switches, High Current Switches, Test Switches, etc.  


Generator or Battery Disconnect Grounding Switch Master Control Switch
Disconnect Switch 4160VAC Knife Switch Pneumatic Disconnect Switch
High Current Switch Knife Switch Special Disconnect Switch 


Filnor designs and manufactures AC/DC electric motor controls and related accessories including pilot control devices, festoon systems and magnet controls. Class 3010 and Class 3011 AC Magnetic Heavy Duty Crane Control for Hoist, Trolley and Bridge Service. NEMA Class I Service, CMAA Classification D, E, & F Service. Pendant Station & Two motion (Joy Stick) Master Switches can be furnished with or without spring return, for AC or DC service, in floor mounting stand or for mounting in console.


Custom and Commercial Power Distribution Equipment:


CDP     Panelboards (Convertible Distribution Panelboard)

FDP     Panelboards (Fusible Distribution Panelboard)

NTCII  Panelboards (Fuse Switch Panelboards)

NLAB   Panelboards (Narrow Box Lighting Appliance Bolted Circuit Breaker)


AC Switchboards & Power Distribution Controls

DC Switchboards & Power Distribution Controls


Custom Cabinet Boxes


Manual Bus Disconnect DC Controls Hand Held Controller
Fuses, Fuse Blocks & Clips



Grid Resistors:

Reliable stainless steel resistor elements and terminals:  All units are triple insulated for 1000Volts AC or DC.  Standard grid resistors in stock to reduce costly downtime.   Stable resistance over wide temperature ranges. High wattage saves space, weight and cost. Standard 26.5" dimensions for quick replacement of other brands.  Custom grids are available.

Helicoil Wirewound:

Applications including: Resistance Neutral Grounding, Braking for AC/DC drives,  


Other uses include Starting and Speed Regulation Uses, Ballast Resistors and Heaters.


Smooth Wirewound:

Applications including: Resistance Neutral Grounding, Braking for AC/DC drives, Starting and Speed Regulation Uses, Ballast Resistors and Heaters.


Neutral Grounding:  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). Whether protecting your equipment or lowering system fault levels, Filnor neutral grounding resistors come in a range of configurations to meet your needs.  Coupled with your generators and transformers, neutral grounding resistors limit ground faults and protect against potentially damaging over-voltages.  Designed for your particular application, we can meet your needs for time rating (5 second to continuous), enclosure style (painted, aluminum, stainless steel, hot-dipped galvanized, etc.) and other options (instrument transformers, elevating stands, bushings, switchgear, controls, etc.).  When shutting down your production is not a cost-effective solution, High-resistance grounding systems allow money to be made while allowing faults are being located and repaired. A range of options is offered to provide the protection and piece of mind you need to keep producing. (All features are quoted upon request, see submittal for details and clarification).

There are three parameters needed to specify the neutral grounding resistor.
1. Rated voltage line to neutral or system voltage
2. Rated fault current
3. Rated “time on” of the line to neutral voltage not exceeding the allowable temperature rise.

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

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.

Standard unit includes the stainless steel resistor assembly plus all the required insulators, internal connections and hardware installed in a standard safety enclosure. Neutral Grounding Resistor units are completely assembled, prewired, and tested at our facility. For shipping all units are crated for added protection and ease of handling.

• 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.
• Heavy powder coat ASA 70 Grey finish provides maximum protection.
• Bottom screening prevents the entry of birds and rodents while providing maximum cooling for the resistors.

• Aluminum, mill galvanized, 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.

• Current or potential transformers mounted and pre-wired at our facility
• ON or OFF Load disconnecting switches
• Space heater
• Specially designed units for hazardous or high altitude locations


Other Markets:  

(All features are quoted upon request, see the submittal for all details and clarification).

  • Harmonic Filters and Damping Resistors:  To be used in conjunction with capacitors and inductors, harmonic filter resistors must dissipate continuous loads and fit easily in the system. Their range of enclosure designs and resistor styles allows for compact assemblies and low induction designs to meet the needs of industrial and utility applications alike. Our engineering staff understands your requirements and will provide service and product with unsurpassed expertise.

  • Dynamic Braking Resistors are used with AC Variable Frequency Drives to produce a braking torque in the motor during overhauling load conditions. The dynamic braking resistor is connected across the DC bus and can see voltages as high as 800 volts (DB Resistors are double insulated and rated for 1,000 volts). The resistance value in Ohms determines the amount of braking torque produced and thus the rate at which the motor will stop. This value must be within acceptable limits for the particular drive and application. The resistor wattage is sized to prevent overheating during normal braking cycles. High duty applications require larger (higher wattage rated) resistors. DB resistors are often added to prevent over-voltage trips on the drive when stopping the motor.

  • Motion & Crane Controls:  Safe and precise starting and stopping of electric motors isn’t a luxury -  it’s a necessity. Their resistors for motor control have been tried and proven to give the long-life and specific ratings needed for your materials handling systems, cranes and hoists. Filnor resistor solutions can be found in mining, pulp and paper, metals refining and ship loading facilities, to name just a few application areas.   

  • Festoon Systems:  Festoon Systems provide a simple, inexpensive method of handling cables and hoses.



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