Intelligent Circuit Breaker

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Intelligent Circuit Breaker LKB3-100

The LKB3-100 is a specialized Photovoltaic Grid-Connection Circuit Breaker designed for safe and intelligent integration of distributed PV systems. It provides comprehensive protection, including overload, short-circuit, over-voltage, under-voltage, and loss-of-voltage protection. A key feature is its auto-reclosing function, which automatically restores power once grid conditions normalize, enabling unattended operation. Rated for 50Hz, 230V/400V AC systems with currents from 6A to 100A, it supports manual/automatic modes and remote control via RS-485/Bluetooth. With a high mechanical endurance of 10,000 cycles and compact DIN rail mounting, it is a robust and essential component for modern solar energy applications

Product Details

Product Descriprion

The LKB3-100 Photovoltaic Grid-Connection Circuit Breaker is an advanced protection device engineered specifically for the demands of distributed solar photovoltaic (PV) systems. Its primary function is to safeguard the electrical line against overloads and short-circuits, while its defining capability lies in managing grid voltage fluctuations critical to PV connectivity.

It integrates multiple protective functions into a single unit: over-voltage protection (trip at 290V±10V), under-voltage protection (trip at 160V±10V), and loss-of-voltage protection. A significant intelligent feature is its auto-reclosing function, which automatically re-engages the circuit after a fault when voltage parameters return to normal, facilitating fully unattended operation. This intelligence is extended through support for remote control, monitoring, and configuration via communication interfaces like RS-485 and Bluetooth.

Electrically, it is rated for 50Hz systems, with options for 1P+N to 4P configurations. The rated current spans from 6A to 100A, with a rated breaking capacity (Ics) of 6kA and both C and D tripping curves. The device offers configurable trip delays for under-voltage/loss-of-voltage conditions (0-10 seconds), allowing for customization based on grid requirements. Its action time is swift at ≤0.5 seconds.

Constructed for durability and reliability, it boasts a mechanical and electrical endurance of 10,000 cycles. It operates effectively within an ambient temperature range of -25°C to +65°C (with limits from -40°C to +70°C) and features a standard 35mm DIN rail mount for easy installation. Combining robust circuit protection with smart grid-interface capabilities, the LKB3-100 is a vital component for ensuring the safety and reliability of residential and commercial PV installations.

Application

Rated Frequency (Hz)	50Hz
Number of Poles	1P+N, 2P, 3P, 3P+N, 4P
Rated Current (A)	6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A, 100A
Rated Voltage (V)	230V AC (1P+N, 2P); 400V AC (3P, 3P+N, 4P)
Short-Circuit Protection (Tripping Curve)	C -Type (5In < I ≤ 10In) D -Type (10In < I ≤ 14In)
Rated Breaking Capacity (Ics)	Icn = Ics = 6kA
Over-Voltage Protection	Trip: 290V ±10V; Restoration: 60V ±10V
Over-Voltage Trip Delay	Trip: 160V ±10V; Restoration: 190V ±10V
Under-Voltage/Loss of Voltage Trip Delay	2 seconds to 10 seconds (Customer configurable: 0s to 10s)
Undervoltage/Loss-of-Voltage Trip Delay (sec)	2 sec ~ 6 sec (Configurable from 0 sec to 10 sec as per customer requirements).
Action Time	≤ 0.5 sec (Excludes delay time)
Operating Ambient Temperature	-25℃ ~ +65℃ Limit operating temperature: -40℃ ~ +70℃
Dielectric Strength	AC 2500V / 1 minute
Rated Impulse Withstand Voltage (Uimp)	4000V
Mechanical and Electrical Endurance	10,000 cycles
Pollution Degree	2
Protection Class (IP Code)	IP20
Tightening Torque	3.5 N·m
Relative Humidity	≤ 90% (at 20℃)
Installation Category	Category II & III

Functional Description

■ Over-load Protection

■ Short-circuit Protection

■ Over-voltage Protection

■ Under-voltage Protection

■ Loss-of-Voltage Protection

■ Auto-Reclosing Function

■ Manual/Automatic Mode

■ Remote Control

■ Indicator Light

Scope of Application

The LKB3-100 Photovoltaic Grid-Connection Circuit Breaker provides overload and short-circuit protection for the line and can also be used for infrequent switching operations. This product is suitable for circuits with a rated frequency of 50Hz, a rated operational voltage of AC 230V/400V, and a rated current from 6A to 100A.

When the voltage returns to normal, the circuit breaker automatically shuts down, enabling unattended, distributed photovoltaic grid integration. Via communication technologies such as RS-485 and Bluetooth allow for remote control of the circuit breaker to automatic closing/power-on and automatic opening/power-off.