





EXB3-125 MCB Breaker – Single Pole to 4 Pole, 1A-63A
The EXB3-125 is a MCB breaker with a 125A frame, rated 1A–63A for AC 50/60Hz circuits up to 400V. Overload and short-circuit protection at 10kA Icu / 7.5kA Ics. Meets IEC 60898-1 and GB/T 10963.1. Six pole configurations: 1P, 1P+N, 2P, 3P, 3P+N, 4P. Trip curves: Type B (3In–5In), C (5In–10In), D (10In–20In). Wide operating range: -35°C to +70°C. 6kV impulse withstand. 20,000 mechanical / 10,000 electrical cycles. IP20 direct, IP40 in distribution box. Top or bottom wiring, TH35-7.5 DIN rail. Full accessory support: OF, SD, MX+OF, MN, MV, MVMN, MNs.
Standards: IEC 60898-1, GB/T 10963.1
Frame Size: 125A | Rated Current: 1A – 63A
Breaking Capacity: Icu 10kA / Ics 7.5kA
Pole Configurations: 1P, 1P+N, 2P, 3P, 3P+N, 4P
Trip Curves: Type B (3In–5In), C (5In–10In), D (10In–20In)
Accessories: OF, SD, MX+OF, MN, MV, MVMN, MNs
Mounting: TH35-7.5 DIN Rail
Product Information
EXB3-125 Single Pole & Double Pole AC MCB – 125A Frame, 10kA, Up to 63A
The EXB3-125 AC miniature circuit breaker (MCB) provides superior thermal performance and fault-clearing capacity compared to standard MCBs. Built on a robust 125A frame, this reliable device offers overcurrent protection for circuits rated up to 63A with a breaking capacity of 10kA Icu / 7.5kA Ics. It is ideally suited for commercial and industrial sub-distribution boards, control panels, and outdoor installations designed to handle extreme temperatures and significant fault currents.
Whether you need a single pole MCB for lighting circuits or a double pole MCB for 400V isolation, the EXB3-125 offers versatility with 1P, 1P+N, 2P, 3P, 3P+N, and 4P configurations. Trip curves B (3–5In), C (5–10In), and D (10–20In) are designed to accommodate resistive, inductive, and high inrush loads respectively. Operating within a broad temperature range between -35°C and +70°C, and equipped to withstand 6kV impulses, the device fits applications such as rooftop equipment and factory panels. Snap-on accessories, including auxiliary contact (OF), alarm contact (SD), shunt release (MX+OF), undervoltage release (MN), overvoltage release (MV), and combination releases (MVMN, MNs), make it versatile for both basic protection and advanced control.
HUYU Electric offers the EXB3-125 at factory-direct OEM/ODM pricing with custom laser marking and comprehensive GB/IEC documentation. It serves as an exceptional alternative to brands like Schneider, ABB, Hager, Eaton, and Chint.

Pole Configurations & Trip Curves – One Platform, All Standard Applications
| Pole | Current Range | Curves | Where It’s Used |
|---|---|---|---|
| 1P | 1A – 63A | B, C, D | Residential lighting, socket circuits |
| 1P+N | 1A – 63A | B, C, D | Single-phase circuits requiring neutral switching |
| 2P | 1A – 63A | B, C, D | Double pole AC circuits, 400V isolation |
| 3P | 1A – 63A | B, C, D | Three-phase motors, distribution panels |
| 3P+N | 1A – 63A | B, C, D | Three-phase with neutral disconnect |
| 4P | 1A – 63A | B, C, D | Full four-pole isolation |
All variants share the same 10kA Icu / 7.5kA Ics mechanism. Type B is tailored for resistive loads such as heating and lighting, Type C is optimal for inductive equipment like HVAC systems and pumps, while Type D is best suited for high-inrush loads like large motors and transformers. Whether your project involves residential single pole MCBs or double pole MCBs for commercial panels, the entire EXB3-125 product line delivers consistent performance with fewer stock-keeping units.
Where the EXB3-125 Is Used – Commercial, Industrial & Outdoor Panels
The EXB3-125 series is designed for applications where standard 63A-frame devices may fall short. In commercial sub-distribution boards, the 125A frame supplies added thermal safety when multiple circuits sustain high loads simultaneously. For industrial control panels, it offers 6kV impulse withstand to handle surges and prevent false trips. Furthermore, its -35°C to +70°C temperature range and IP40-rated enclosure make it ideal for rooftop HVAC units and outdoor equipment setups. The optional accessory line, featuring OF, SD, MX+OF, MN, MV, MVMN, and MNs, integrates smoothly into building automation or PLC systems, providing shutdown and alarm capabilities.
Technical Specifications
| Product Model | EXB3-125 |
| Series | EXPLORER |
| Standards | GB/T 10963.1, IEC 60898-1 |
| Frame Size | 125A |
| Poles | 1P, 1P+N, 2P, 3P, 3P+N, 4P |
| Rated Current (A) | 1, 2, 3, 4, 6, 10, 16, 20, 25, 32, 40, 50, 63 |
| Rated Voltage | AC 230V (1P, 1P+N); AC 230/400V (2P); AC 400V (3P, 3P+N, 4P) |
| Frequency | 50/60Hz |
| Icu / Ics | 10,000A / 7,500A |
| Impulse Withstand Uimp | 6kV |
| Dielectric Test | 2,000V (1 min) |
| Tripping Curve | B (3In–5In), C (5In–10In), D (10In–20In) |
| Electrical / Mechanical Life | 10,000 / 20,000 cycles |
| Operating Temperature | -35°C ~ +70°C |
| Anti-Humidity | 28 cycles, RH 90–96% at 55°C |
| Max. Wiring | 25mm² |
| Mounting | TH35-7.5 DIN Rail, top or bottom |
| Protection Degree | IP20 direct / IP40 in distribution box |
| Accessories | OF, SD, MX+OF, MN, MV, MVMN, MNs |
| MOQ | 2,000 pcs per item |

Compare Our 10kA AC MCB Price & Lead Time
Single pole, double pole, 3P, and 4P options from 1A to 63A, with a full accessory range. GB/IEC certified, 125A frame for thermal margin. Request a wholesale quotation and see how our factory-direct pricing and OEM terms compare to your current MCB supplier.
MOQ 2,000 pcs • GB/T 10963.1 / IEC 60898-1 • Worldwide Shipping
Factory-Direct OEM/ODM Supply – Alternatives to Major Brands
EXB3-125 – A Practical Alternative for Distributors
Brands like Schneider, ABB, Hager, Eaton, Siemens, Legrand, and Chint dominate the MCB market, but their lead times and minimum order conditions don’t always fit every project. The EXB3-125 bridges that gap with an IEC 60898-1 and GB/T 10963.1 compliant design, providing 10kA breaking capacity, a 125A frame for enhanced thermal performance, and seven accessory options. It’s available with private labeling and custom packaging at competitive factory-direct terms.
How to Choose the Right AC MCB – Current, Curve & Accessories
A practical reference for specifying the correct EXB3‑125 configuration.

1. Which Current Rating Fits Your Load?
For residential lighting and small appliances, a 6A–10A single pole MCB is typical. Socket outlets and general circuits use 16A–20A. Air conditioners, water heaters, and small motors need 25A–40A. For feeder circuits or larger equipment, 50A–63A is appropriate. Because the EXB3‑125 uses a 125A frame, even a fully loaded 63A circuit runs with less thermal stress than in a standard 63A‑frame breaker.
2. B, C, or D Curve?
Type B (3–5In): resistive loads only — incandescent lighting, electric heating, cooktops. Type C (5–10In): the correct choice for most commercial and industrial circuits with motors, compressors, or fluorescent lighting. Type D (10–20In): select this for transformers, large motors, welding equipment, or any load with a significant inrush current. The tripping curve chart above shows the exact time‑current behavior for each curve.
3. Single Pole, Double Pole, or Three Phase?
Use a single pole MCB (1P) for 230V lighting or socket circuits. Choose a double pole MCB (2P) when you need 400V isolation or disconnected neutral. For three‑phase systems, 3P protects motors and main distribution, 3P+N adds neutral switching, and 4P provides complete isolation. All pole variants share the same 125A frame and 10kA rating.
4. Adding Remote Control & Monitoring
The EXB3‑125 accepts seven snap‑on accessories without tools. An OF auxiliary contact reports the breaker’s open/closed status. An SD alarm contact signals a trip event. A shunt release (MX+OF) allows remote tripping. Undervoltage (MN), overvoltage (MV), and combination releases (MVMN, MNs) protect connected equipment from voltage anomalies. These functions turn a standalone circuit breaker into an active part of a building management or PLC system.




Frequently Asked Questions
What is MCB in breaker?
MCB stands for Miniature Circuit Breaker. It automatically disconnects a circuit during overload or short-circuit, and can be reset by switching it back on — unlike a fuse, which must be replaced.
What is MCB, MCCB, ELCB, and RCCB?
MCB protects against overcurrent up to 125A. MCCB handles higher currents with adjustable trip settings. ELCB (Earth Leakage Circuit Breaker) is an older earth‑fault device. RCCB (Residual Current Circuit Breaker) detects leakage current for shock protection. The EXB3‑125 is an MCB; pair it with an RCCB for combined overcurrent and earth‑leakage protection.
What is the difference between MCB and MCB?
Two MCBs can differ in trip curve (B vs C vs D), breaking capacity (6kA vs 10kA), and frame size (63A vs 125A). A 125A‑frame, 10kA MCB will run cooler and clear higher faults than a standard 63A‑frame, 6kA model — important for heavily loaded commercial panels.
What is the difference between MCB and RCD breakers?
An MCB protects against too much current. An RCD protects against current leaking to earth. They serve different safety purposes. A combined device is called an RCBO. The EXB3‑125 is a pure overcurrent MCB; use it alongside an RCCB or RCBO for complete protection.
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