SGB5-40P is a professional DC miniature circuit breaker designed for photovoltaic systems. It adopts double breakpoint structure and UC control technology, supports 500V–1500V DC voltage levels, and provides reliable overcurrent and short-circuit protection for solar PV arrays and combiner boxes.
Key Features
- Double breakpoint arc extinguishing structure
- UC control for stable DC protection
- 1P / 2P / 3P / 4P pole options
- Wide DC voltage range: 500V–1500V
- Rated current: 6A–40A
- 1500A breaking capacity
- Compliant with GB/T 14048.2 & IEC/EN 60947-2
- DIN‑rail mounting for easy installation
- Specially designed for PV DC circuits
Technical Parameters
| Rated Voltage(V) | Pole | Rated Current
(A) | Breaking Capacity
Icn (A) | Executive Standards |
| DC 500V | 1P | 6.10.16.20.25.
32.40A | 1500A | GB/T 14048.2
IEC/EN 60947-2 |
| DC 1000V | 2P |
| DC 1500V | 3P |
| DC 1500V | 4P |
Application Scenarios
- PV Solar Systems: DC string and combiner box protection
- Solar Power Stations: Utility and commercial PV plants
- PV Inverters: DC input side protection
- Off‑grid Solar Systems: Battery and solar circuit safety
- Industrial DC Distribution: Stable DC load protection
- New Energy Equipment: DC power control and safety
Company Introduction
Zhejiang Singi Electrical LLC
SINGI is a professional manufacturer of DC circuit breakers and PV protection devices. We focus on photovoltaic, energy storage, and new energy circuit protection solutions. Our products comply with international IEC, EN, and national GB standards, featuring stable performance, high safety, and strong adaptability. SINGI provides reliable protection for solar power systems, industrial DC power, and global new energy projects.
FAQ
Q: What is the advantage of double breakpoint structure in SGB5‑40P DC MCB?A: Double breakpoint uses two separate contact gaps to extinguish DC arcs. Compared with single breakpoint, it provides stronger arc extinguishing capability, higher voltage resistance, and faster breaking speed, making it much safer for high‑voltage DC PV systems up to 1500V.
Q: Why is SGB5‑40P more suitable for PV systems than general DC breakers?A: PV systems produce unstable DC current with strong arc generation risks. SGB5‑40P uses double breakpoint and UC control to suppress arcs effectively, ensuring stable protection in long‑string, high‑voltage solar applications where ordinary breakers may fail.
Q: What does “UC control” mean in this DC MCB, and how does it improve performance?A: UC control refers to under‑voltage and over‑voltage integrated protection logic. It stabilizes tripping characteristics under fluctuating DC voltage in PV systems, preventing malfunction tripping or delayed protection, ensuring stable operation in outdoor solar environments.
Q: Why can this MCB support from 500V up to 1500V DC with different pole configurations?A: Voltage level is matched with the number of poles: 1P for 500V, 2P for 1000V, 3P/4P for 1500V. Each pole unit shares the arc extinguishing load, so the breaker can safely adapt to different PV system voltage levels without changing core structure.
Q: Is 1500A breaking capacity sufficient for PV string protection?A: Yes. PV strings typically have limited short‑circuit current. 1500A breaking capacity is fully sufficient to safely disconnect string faults while ensuring compact size, cost efficiency, and long service life for string‑level protection.
