The 40D series zinc oxide varistors are designed for high-energy surge protection. Their zinc oxide particle matrix structure provides bidirectional nonlinear overvoltage protection. Their varistor voltage ranges from 200V to 1800V, with a tight tolerance of ±10%. They offer a maximum current capacity of 6500A based on an 8/20μs waveform and an energy absorption rating of up to 1080J based on a 2ms square wave. They support a four-level protection system. Standard models offer currents from 400A to 6500A, while enhanced versions (KJ) increase current capacity by 250% to 150%, such as the 20D model, which achieves a peak of 10kA. The KH model complies with IEC61000-4-5 and can withstand 40 surges of a 6kV/3kA combined wave. The KX customizable model supports a single 10kA surge or 500 repetitive surges.
The cylindrical structure has a diameter of 20mm and a thickness range of 7.5mm to 16mm, and operates over a wide operating temperature range of -45°C to 125°C. The varistor voltage temperature coefficient is less than 0.05%/°C, and the static power consumption is only 1.4W. Certified by UL1449, IEC61051, and GB/T10193, it is suitable for high-intensity surge protection scenarios such as communication base station power supplies, railway signaling systems, low-voltage distribution equipment below 1000V, and industrial welding machines.