Vishay Intertechnology, Inc. has introduced a series of neutral ground resistors for industrial power systems. Consisting of the company's GRE1 high-power, high-current grid resistors mounted in rugged, weatherproof IP23-rated enclosures with extremely high voltage insulation, Milwaukee Resistors (a product line of Vishay Dale Resistors) NGR series devices combine high line-neutral and system voltages with high-temperature performance to +760 °C.
Offering a convenient drop-in replacement for competing solutions, NGR series resistors are designed to provide ground fault, overvoltage, and short circuit protection for generators and transformers in wye (star) configurations without exceeding the temperature limitations outlined by IEEE-32. The devices offer line-neutral voltage from 1.39 kV to 8 kV, system voltage from 2.4 kV to 13.8 kV, and current ratings from 100 A to 1000 A. Resistance for the resistors ranges from 1.39 W to 80 W with tolerance of ± 10 %.
The RoHS-compliant resistors offer a tied live design to eliminate floating voltages in the assembly and lifting eyes for safe and easy installations. Featuring a stainless steel element, ceramic insulators, and multiple taps, the NGR series provides high reliability with a welded construction. Additionally, the devices' open design allows for maximum cooling efficiency. The units are offered in modular or custom designs. Production quantities of the NGR series are available now, with lead times starting at five to six weeks.