DC Moulded Case Circuit Breaker

Critical Technical Parameters for DC Circuit Protection

Rated Operating Voltage (Ue) & Arc Extinguishing Technology: Ensure the breaker matches system DC voltages (e.g., 250V, 500V, 750V, 1000V, or 1500V DC). NUOMAK DC MCCBs feature specialized magnetic blow-out arc chutes and extended contact gaps that rapidly stretch and extinguish continuous DC arcs.

Polarity Requirements (Non-Polarized vs. Polarized): For battery storage systems (BESS) where current flows in both charging and discharging directions, non-polarized DC MCCBs are essential to prevent breaker damage under reverse current flow.

Frame Sizes & Pole Configurations: Available in 1P, 2P, 3P, and 4P series configurations across current ratings from 16A up to 1600A, allowing flexible series wiring to increase voltage withstand capacity.

Breaking Capacity (Icu/Ics): Evaluate ultimate short-circuit breaking capacity (Icu) up to 50kA at high DC voltages to ensure full system protection during catastrophic short circuits.

Quality Standards & Factory Testing Compliance

All NUOMAK DC Moulded Case Circuit Breakers are manufactured under ISO9001 certified processes and strictly comply with IEC/EN 60947-2 standards for DC low-voltage switchgear. Every DC breaker undergoes 100% routine factory inspection—including high-voltage dielectric withstand, DC thermal calibration, and mechanical switching endurance trials—guaranteeing smooth import compliance for distribution in European, Asian, Middle Eastern, and American markets.

Key Target Applications

Solar Photovoltaic (PV) Systems: Main DC isolation and short-circuit protection between PV combiner boxes, solar string arrays, and central/string inverters.

Battery Energy Storage Systems (BESS): Bi-directional overload and fault protection for commercial and utility-scale lithium battery racks and uninterruptible power supplies (UPS).

EV Charging Infrastructure & DC Microgrids: High-voltage DC feeder protection for fast-charging stations and industrial DC distribution networks.

What is the primary difference between an AC MCCB and a DC MCCB?

AC current naturally passes through a zero-voltage point 100 or 120 times per second, making arc extinguishing relatively easy. DC current maintains constant voltage without zero-crossing points, producing persistent, intense electrical arcs during trip clearance. DC MCCBs feature specialized internal magnetic arc chutes and wider contact gaps specifically engineered to stretch and break DC arcs safely. Standard AC MCCBs cannot be used in high-voltage DC applications without derating or risk of fire.

Are NUOMAK DC MCCBs non-polarized for bi-directional battery storage systems (BESS)?

Yes. NUOMAK provides non-polarized DC MCCB models specifically engineered for energy storage systems (BESS) and bi-directional DC microgrids. Non-polarized DC MCCBs maintain full breaking capacity and arc-extinguishing performance regardless of whether current flows from charger-to-battery or battery-to-load.

What is the Minimum Order Quantity (MOQ) and lead time for wholesale DC MCCB orders?

For standard catalog models, our MOQ starts as low as 10 to 30 units per frame size to support trial orders. For custom OEM orders (including private label branding, custom casing colors, and special DC voltage ratings), the MOQ is typically 100 units. Standard factory production lead times range from 15 to 25 business days, backed by full ISO9001 quality certificates and CE test reports.