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


Customized Load Banks

Load Banks provide electrical loads for testing purposes and reduce undesirable conditions in back-up generating systems. With multiple element types at our disposal, a reliable and efficient product tailored to your needs is always available.  All of the resistors are made in house so they  are not captive to any supplier’s delivery schedule.  The unique ability to design and supply to your specifications is our advantage; a quality product delivered in a timely manner at a reasonable price is yours.

Radiator & Duct Mounted Load Banks: Using the engine’s radiator air flow for cooling the resistor elements, these load banks are suitable for use on stationary and portable generator sets. Dimensions are matched to your core making this a cost effective solution for periodic testing and minimizing “wet· stacking”. Sizes range from 10 to 1500 kW at 208 to 600 VAC. Steps can be configured as required. 

Stationary Load Banks:  Whether indoor or outdoor, purely resistive or resistive/reactive, a solution is readily available. Each model can be modified for a particular application, such as adding iron-core reactors, control power transformers, remote mountable controls, digital metering, lockable access doors, and a host of other possibilities.  Alternatively, these banks may be trailer mounted for increased flexibility.  Available in low and medium voltages, models range from 15 to 4000 kW, with reactive loading possible from 15 to 3000 kVAR. 

Portable Load Banks:  A complete line of portable load banks, ready for shipment when you need them. With their engineering experience and manufacturing capabilities combined with your application, we can have a custom designed product that will meet your particular needs.  Hand carried, on casters or lifting channels, we have a solution for your requirement. AC load banks are available from 120 to 600 VAC, and capacities ranging from 10 to 800 kW (resolution as required for your particular application). DC load banks are rated up to 1000 amps with voltages spanning 24 to 270 VOC.

LOAD BANK models are available in many configurations...


Indoor Ductable or Weatherproof, and Radiator Mounted


Containerized Caster, Fork- Liftable, or Trailer mounted


National Electric Code, NEMA, NFPA 70, 99, 110


120VAC single phase to 25KVAC 3 phase; (DC is available)


Natural-Cooled or Forced Air


20KW to 2MW (Can gang together units to any size)

Filnor has load bank designs for a variety of applications, including:  Fuel cell, UPS and battery system testing; factory or field testing of engine generator sets and turbines; exercising of back-up power systems; and optimizing loads for prime power situations.

· Load Bank General Description:

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


Filnor load banks will be resistive (or resistive/reactive) per the customer’s specification for use as an electrical load for diesel generators or equivalent.  The load bank will be one of several available types: portable, stationary, trailer-mounted or radiator/duct mounted.  While standard designs exist, multiple options are possible for the enclosure style, controls and accessories.

Ratings:  As a manufacturer of power resistors, they are able to offer an infinite range of ratings.  Selection criteria is based on AC or DC use, single or three phase as well as the voltage and current combination.  

Resistors: Filnor resistors are chosen per the particular rating and application of the load bank they are to be used in.  They can be Grid, Helicoil Wirewound, or Smooth Wirewound (as selected for the power steps required).   Wound elements are made of a stainless steel alloy, wound on a ceramic core, suspended on stainless steel rods.  The rods are subsequently mounted within a supportive channel structure.   The Grid elements are a stamped and welded or continuous resistor weave, made of a stainless steel alloy and developed for heavy-duty applications.  The resistor is anchored by high temperature insulators and then mounted in a channel structure.   All resistors are rated for continuous duty and do not require a cool-down period.  Unless otherwise specified, the resistors are connected in a delta scheme.

Cooling: The standard cooling arrangement for non-radiator mount units is for one or multiple fans per section of resistor assemblies. Standard fans are rated 208V, 3 phase, 60Hz for 208VAC load banks, 240V, 3 phase, 60 Hz for 240VAC load banks, or 480V, 3 phase, 60 Hz for either 480VAC or 240/480VAC load banks.  Power to the fan is customer supplied unless otherwise specified.  Please refer to submittal drawings for clarification. Radiator/duct mounted applications are designed to be cooled by an engine mounted generator fan. (All features are quoted upon request, see submittal for details and clarification).

Control equipment: As a standard, load banks are supplied with the controls integral to the resistor assembly enclosure.  Other options exist including a remote cabinet for the main controls (cabling done by the customer between the load bank and remote cabinet).   Control power (120 V) is customer supplied unless a control power transformer is included in the offer. Controls typically consist of a Main Power On/Off switch, Blower On/Off switch with indicator (where appropriate), Voltage selector switch (for dual voltage models) Load Steps On/Off switch and individual step controls with indicating lamps.  Individual step controls are tied to contactors rated in accordance with the step’s particular amperage.  Optional equipment available include: Analog or Digital metering, automatic load leveling, and automatic load dump.

Enclosures: The load bank will consist of an enclosure with resistor assemblies, control circuitry, and ventilation equipment (where applicable). The enclosure will be of type NEMA 1 (unless otherwise specified), Enclosure finishes and materials are also application specific. Options include louvers (NEMA 3R, NEMA 12), protective screening, lifting handles, lugs and/or channels, and casters.  Hot rolled steel with ASA70 gray epoxy powder coat is the Filnor standard with options including mill galvanized, aluminum and stainless steel, or special color. Ventilation will be either horizontal or vertical based on the application and the customer’s specification.  Depending on the application, the load banks are natural convection cooled or forced air-cooled. A host of options are available including high temperature cut-out switches, alarm relaying, RTD’s, and door/panel mounted instrumentation.  Radiator/duct mounted applications are sized to meet the customer’s requirement.  The frame may be lifted with slings, or optionally with lifting lugs if specified.  A removable access plate and conduit entries are provided for the customer’s connections.

Protection equipment: Typical protection equipment includes a differential pressure switch to provide an airflow alarm, (optional on radiator mount units).  Automatic Load Dump Feature: This is typically coupled to an indicating lamp and general-purpose relay to open load step contactors in the event of a failure.  A temperature-sensing switch operates in the same fashion.  Optional equipment includes fusing for the fan, incoming connection and individual load steps.

Documentation: Filnor will provide a general outline drawing and an electrical schematic drawing to the customer for approval within two weeks of receipt of a technically clear and official order.  These drawings must be returned approved prior to manufacturing.  One operation and maintenance manual will be shipped with each load bank and additional copies are available at a nominal adder. (All features are quoted upon request, see submittal for details and clarification).


High Current Load Bank for NYC Transit System

 Load Bank Assembly for Crane



Other Markets: (All features are quoted upon request, see submittal for 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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