DC MCB 10kA 1-Pole 300V — DC Miniature Circuit Breaker for Solar PV

DC MCB 10kA 1-Pole 300V — DC Miniature Circuit Breaker for Solar PV, Battery Storage & EV Charging

The DGB3-80DC is a 1-pole DC-rated Miniature Circuit Breaker (MCB) specifically designed for direct current (DC) applications including solar PV string protection, battery energy storage systems (BESS) and EV charging DC infrastructure. Unlike standard AC MCBs, this DC MCB incorporates an arc-extinguishing chamber engineered to safely interrupt DC fault currents — where the absence of a natural current zero crossing makes arc extinction significantly more challenging.

Rated at 300V DC with a 10kA breaking capacity and Type C trip characteristic, the DGB3-80DC provides reliable overcurrent and short-circuit protection on DC circuits from 16A to 80A. It is manufactured to IEC/EN 60947-2 and is suitable for 35mm DIN rail mounting in solar PV combiner boxes, battery storage enclosures, EV charging distribution boards and other DC power distribution equipment.

For solar PV installations, two 1-pole DC MCBs can be connected in series for higher voltage applications (up to 600V DC). The MCB is polarity-sensitive — correct wiring orientation is essential for safe DC arc interruption.

Key Features

• Purpose-built for DC circuits — arc-extinguishing chamber designed for DC fault interruption
• 300V DC rated per pole — suitable for solar PV strings, battery systems and DC EV infrastructure
• 10kA DC breaking capacity — high fault-level protection for commercial and industrial DC systems
• Type C trip curve — suitable for solar inverter input circuits and battery charge/discharge paths
• Full current range: 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A
• 1-pole configuration — series-connectable for higher voltage DC applications (2P for 600V DC)
• 35mm DIN rail mounting — fits standard combiner boxes, enclosures and distribution boards
• Polarity-sensitive design — clearly marked terminals for correct DC wiring
• Contact position indicator — visual on/off and trip status
• IP20 finger-safe terminals — suitable for indoor panel installation

Technical Specification

Applications

• Solar PV string protection — protects individual PV strings in combiner boxes
• Battery energy storage systems (BESS) — overcurrent protection on battery charge/discharge circuits
• EV charging DC infrastructure — protection on DC bus and charge controller circuits
• DC power distribution — general-purpose DC circuit protection in industrial and commercial systems

Compliance & Certification

• Manufactured to IEC/EN 60947-2
• CE certified
• Suitable for solar PV installations compliant with BS 7671 (18th Edition) Section 712
• Suitable for EV charging installations compliant with BS 7671 Section 722

Installation Notes

This DC MCB must be installed by a qualified electrician or solar PV installer. Always isolate the DC supply before installation — DC circuits carry continuous current and do not have a natural zero crossing point, making them more hazardous to work on than AC circuits. This MCB is polarity-sensitive: connect the supply (positive) to the top terminal marked with the incoming arrow, and the load to the bottom terminal. Incorrect polarity will compromise the arc-extinguishing capability. For PV string voltages above 300V DC, connect two 1-pole MCBs in series to achieve 600V DC rating.