LKB3-100 PV Grid-Tie IoT Circuit Breaker | Full Features & Selection Guide

1. Main Application Scope

1. PV Grid-Tie System: Built-in detection for overvoltage, undervoltage, loss of voltage, phase failure, and power outage. It will automatically reclose when grid parameters return to normal, effectively solving the anti-islanding problem and complying with PV grid connection regulations.
2. General Circuit Protection: It can replace conventional breakers to provide reliable overload and short-circuit protection for power distribution lines, ideal for cabinet retrofitting and replacement of old equipment in PV box substations.
3. Remote O&M: Supported by dual communication interfaces, the breaker can be remotely switched and monitored, realizing unattended automatic management for distributed solar power plants and reducing on-site maintenance costs.

2. Core Product Features

2.1 Comprehensive Electrical Protection & Reliable Performance

• Basic Protection & Structure: Adopts flame-retardant PA66 housing with IP20 protection grade. It integrates overload, short-circuit, phase failure, and Earth Leakage protection, perfectly adapting to standard distribution cabinets and outdoor PV box substations.
• PV-Specific Voltage Protection: Trips at 200V±10V (undervoltage) and 290V±10V (overvoltage). automatic reclosure activates when voltage recovers to 260V±10V. The loss-of-voltage delay is factory set from 2s to 6s and can be customized within 0~10s to avoid false tripping caused by transient grid fluctuation.
• Excellent Operating Performance: Total breaking time ≤ 0.5s. Mechanical endurance: 10,000 operations; Electrical endurance: 6,000 operations. It supports cables up to 35 mm², ensuring stable long-term operation.

2.2 Dual Manual / Automatic Operation with Safety Interlock

• automatic Mode: Works for regular PV grid connection. It trips automatically under abnormal grid conditions and recloses when the grid recovers and accepts remote control commands.
• Manual Mode: For maintenance and inspection. Remote control and auto-reclose functions are disabled; only local operation is allowed to prevent accidental closing and potential safety hazards.
• Status Indicators: Clear LED indicators show closing, opening, and fault status for quick status check and fault location.

2.3 Dual IoT Communication for Intelligent Management

• RS-485 Communication: Enables network connection with distribution monitoring systems and PV central control platforms. Real-time data of voltage, current, and switch status can be collected, and batch remote switching is available for large-scale solar farms.
• Bluetooth Communication: Supports on-site parameter configuration, fault diagnosis, and debugging via mobile devices without opening the unit or rewiring, greatly improving on-site working efficiency.

2.4 Prepaid Meter Compatibility

3. Model Selection Chart

4. Installation & Safety Instructions

4.1 Installation Environment

• Operating temperature: -40℃ ~ +70℃ (stable working range: -25℃ ~ +66℃)
• Altitude: Applicable for areas below 2000m. A custom version is available for high-altitude regions.
• Installation: Standard 35mm DIN rail mounting. Install vertically with inclination angle ≤ 5°. The handle upward means the closed position.
• Compliance: Conforms to GB/T19334.1 standard, direct replacement for traditional breakers.

4.2 Safety Warnings

1. Do not install or maintain the unit while live. Never short-circuit the live wire and the neutral wire for testing, as this will cause permanent damage to internal modules.
2. Always switch to manual mode before maintenance to cut off auto-reclose and remote control circuits.
3. Distinguish live wire (L) and neutral wire (N) correctly. Reversed wiring will lead to protection failure. Do not disassemble or adjust internal settings arbitrarily.
4. Fault interlock design: After tripping due to overload or short circuit, manual reset is required even if the faults are removed.

4.3 Installation & Commissioning Steps

1. Check the rated voltage and current on the nameplate, and set the switch to manual mode before installation.
2. Clip the breaker onto the DIN rail firmly, and connect L & N wires correctly and tightly.
3. Switch to automatic mode after installation. The unit will run a self-check automatically. Test the auto-switch function under simulated overvoltage and undervoltage conditions. Put into formal operation after full inspection.

5. Model Definition & Ordering Guide

5.1 Model Explanation

• LK: Enterprise code
• B: Frame size code
• 3: Design serial number
• 100: Frame-rated current

5.2 Ordering Requirements

6. Product Summary