The QKM5L series Residual Current Operated Circuit Breakers (here in after referred to as the circuit breakers) are products developed by our company to meet the requirements of urban and rural power grids and other applications needing residual current reclosing functionality. This series of circuit breakers is suitable for three-phase four-wire low-voltage grids with a directly grounded neutral point, operating at an AC frequency of 50 Hz, a rated voltage of up to 400 V, and a rated insulation voltage of 1000 V. The circuit breakers are available in three frame sizes: 125 A, 250 A, and 630 A, with rated currents ranging from 50 A to 630 A and rated residual operating currents ranging from 50 mA to 1000 mA. They feature overload protection, short-circuit protection, residual current protection, overvoltage protection, undervoltage protection, phase-loss protection, mutation protection, harmonic protection, zero-loss protection, and reclosing functions. The communication functions include power line carrier (HPLC), Bluetooth, infrared, and RS-485 ports. The energy metering functions cover both active and reactive power, with high-precision voltage and current detection, enabling remote signaling, remote measurement, remote regulation, and remote control. The products are compact in size, meeting the dimensional requirements of meter boxes.
The circuit breakers comply with the following standards: GB/T 14048.2 “Low-voltage switchgear and controlgear – Part 2: Circuit-breakers”; GB/T 32902 “Residual Current Operated Circuit-Breakers with Automatic Reclosing Function (CBAR)”; and Q/GDW 1365 “Technical Specification for Security Authentication of Smart Energy Meter Information Exchange.”