Ground Fault Relays

To service the special needs of the mining industry I-Gard has developed the GCHK-100 ground fault relay to improve safety for personnel and equipment in underground or above ground applications. Detection of ground faults is important where safety from electric shock and fire risk can occur and cause serious equipment and personnel hazards. The relay is designed for use with Resistance-Grounded systems up to 4160V but could be used with Grounded Systems in branch circuit applications where Load current is limited to 800 Amps.

DSP Ohmni

The DSP system is designed to detect the event of a single ground fault, signal an alarm, and point to the affected branch or feeder. Thus maintenance can be immediately alerted to the problem and an operator dispatched to locate the fault to isolate it promptly. The DSP system can assist in locating the fault with a pulsing fault location circuit. In the event of a second ground fault, the DSP acts quickly to prevent loss of two feeders by selectively tripping the lower priority feeder only.

Neutral Grounding Resistors (NGR)

I-Gard offers a complete range of Neutral Grounding Resistors from 277V to 69,000 volts and these are used for resistance grounding of industrial power systems and are usually connected between earth ground and the neutral of power transformers, power generators or artificial neutral transformers. Neutral Grounding resistors are similar to fuses in that they do nothing until something in the system goes wrong. Then, like fuses, they protect personnel and equipment from damage. Damage comes from two factors, how long the fault lasts and how large the fault is.Ground fault relays trip breakers and limit how long a fault lasts. Neutral grounding resistors limit how large the fault is.

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Dynamic Braking Resistors

Dynamic Braking Resistors are used with AC Variable Frequency Drives to produce a braking torque in the motor during overhauling load conditions. They are double insulated rated at 1000 volts. The resistance value in ohms determines the amount of braking torque produced, and thus the rate at which the motor will stop. The resistor wattage is sized to prevent overheating during normal braking cycles. Dynamic Braking Resistors are often added to prevent over-voltage trips on the drive when stopping the motor.

Harmonic Filters

I-GARD is the leading manufacturer of custom resistor assemblies for harmonic resistor banks, offering a range from single, low wattage, high resistance elements, to large, multi element, 150kW banks. Our in-house, skilled engineering allows precision designs, including challenging or special requirements such as low inductance designs, and impulse withstand and testing. All products are produced within I-GARD's certified ISO 9001 quality assurance program. Our wide range of resistor components provides the flexibility to manufacture a wide range of harmonic filter resistors to suit your requirements.