Neutral ground resistors offer line-neutral voltage to 8kV
Designed for industrial power systems, the NGR series of neutral ground resistors has been released by Vishay Intertechnology. The devices, which consist of the company's GRE1 high-power, high-current grid resistors mounted in rugged, weather-proof IP23-rated enclosures, combine high line-neutral and system voltages with high-temperature performance of up to +760°C.
Offering a convenient drop-in replacement for competing solutions, the 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 to 8kV, system voltage from 2.4 to 13.8kV, and current ratings from 100 to 1000A. Resistance for the resistors is in the range of 1.39-80Ω with a ±10% tolerance.
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.