Zero-sequence current transformers are used in conjunction with relay protection devices or signals when zero-sequence grounding currents are generated in the power system, causing the device components to operate, thereby achieving protection or monitoring.

Our BHG-LJ series residual current transformers (cable type) are high-precision devices with various capacities, turns ratios, and accuracy limit factors. They include high-sensitivity versions for low current grounding selection and relays. These transformers are housed in an ABS engineering plastic shell, fully sealed with resin, ensuring good insulation and aesthetic appearance. They boast high sensitivity, good linearity, reliable operation, and easy installation. Their performance surpasses that of general residual current transformers and have a wide range of applications, accommodating electromagnetic relay protection as well as electronic and microcomputer-based protection devices. Users can select the appropriate residual current transformer based on the system's operating mode (neutral grounding or ungrounded, grounded through a large resistor, grounded through a small resistor, or grounded through an arc suppression coil).