Schneider MC-4/11/03/400 is a 4-pole miniature circuit breaker (MCB) developed by Schneider Electric, specifically engineered for low-voltage three-phase four-wire power distribution systems.

 It is widely used in industrial machinery power circuits, commercial building auxiliary power loops, and small-scale three-phase electrical equipment protection, focusing on safeguarding branch circuits against overloads and short circuits.

The model’s coding carries key technical specifications: “4” indicates 4 poles (compatible with three-phase live wires + neutral wire), 

“03” corresponds to a rated current of 10A (a common rating for medium-load branch circuits), and “400” represents a rated breaking capacity of 400A—ensuring it can safely interrupt fault currents without structural damage.

 It adopts Schneider’s mature thermal-magnetic tripping mechanism: thermal elements trigger delayed tripping during overloads (preventing long-term circuit overheating), 

while magnetic elements achieve instantaneous tripping during short circuits (quickly cutting off high fault currents to avoid equipment burnout or fire hazards).

In terms of installation and compliance, the MCB features a compact DIN rail-mountable design, enabling easy integration into standard low-voltage distribution cabinets and reducing space occupation. 

It meets international safety standards such as IEC 60898-1, with a flame-retardant PC housing that enhances fire resistance in electrical fault scenarios. Additionally, 

it maintains stable performance across an operating temperature range of -25°C to +60°C, adapting to harsh industrial or variable commercial environments, and ensuring long-term reliable protection for low-voltage power distribution systems.

中文产品描述

其型号编码蕴含关键技术参数：“4” 代表 4 极结构（适配三相火线 + 零线的三相四线系统），“03” 对应 10A 额定电流（适配中负载分支回路，如小型三相电机、多组单相设备组合供电等场景），“400” 则表示 400A 额定分断能力 ——

 可在故障电流产生时安全分断电路，避免自身损坏或故障扩大。

该断路器采用施耐德成熟的热磁脱扣机制：过载时，热元件通过受热形变触发延时脱扣，防止电路长期过热导致绝缘老化；短路时，磁元件在强电流磁场作用下瞬时动作，快速切断故障回路，避免设备烧毁或引发火灾。

在安装与合规性上，这款 MCB 采用紧凑的 DIN 导轨安装设计，可轻松嵌入标准低压配电柜，减少空间占用；产品符合 IEC 60898-1 等国际安全标准，外壳采用阻燃 PC 材质，在电气故障时能有效阻火，提升配电系统安全性。

此外，它可在 - 25°C 至 + 60°C 的宽温范围内稳定工作，既能适应工业车间的温差环境，也能满足商业场所的多变工况，为低压配电网络提供长期可靠的保护。