As construction sites, outdoor event venues, commercial buildings, industrial plants, and temporary power installations demand robust electrical distribution solutions, 400A Distribution Boxes have become an essential product for managing medium‑to‑high electrical loads. A 400A Distribution Box is an electrical panel designed to distribute incoming electrical power at 400 amps to multiple outgoing circuits while providing protection against overload, short circuits, and electrical faults through integrated protection devices. These systems are configured to support power distribution for heavy machinery, lighting arrays, motor drives, welding systems, heating elements, and temporary power connections in complex installations.
Unlike smaller distribution panels, 400A Distribution Boxes must handle higher current capacity and often incorporate advanced protection elements, busbar systems, surge protection devices, and modular components to adapt to specific project requirements. Enclosure materials vary from powder‑coated mild steel, galvanized steel, aluminum alloy, to SUS304 stainless steel. The latter offers approximately 18% chromium and 8% nickel in composition, providing corrosion resistance and mechanical strength for installations exposed to moisture or harsh environments, such as outdoor construction sites and coastal project locations.
Industry professionals source 400A Distribution Boxes for applications such as temporary power delivery on construction sites, main service distribution panels in commercial buildings, generator power distribution for backup systems, electrical projects requiring portable power modules, and industrial equipment installations requiring segmented power control.
Below is a list of ten notable 400A Distribution Box suppliers in China, along with detailed descriptions of their product offerings, engineering capabilities, and application scenarios.In No Particular Order
APEKS ELECTRIC CO., Ltd.
APEKS ELECTRIC CO., Ltd. is a supplier of electrical distribution equipment focusing on medium‑to‑high load systems such as 400A Distribution Boxes. The company's distribution boxes are engineered to deliver electrical power from a primary supply panel, transformer output, or generator source to multiple protected circuits using modular protection devices such as MCCBs (Molded Case Circuit Breakers), RCBOs (Residual Current Breaker with Overload), RCCBs (Residual Current Circuit Breakers), surge protection modules, and integrated metering systems.
Enclosures are fabricated from powder‑coated steel, galvanized steel, aluminum alloy, and optionally SUS304 stainless steel depending on project requirements. A powder‑coated steel box might be specified for indoor electrical rooms and semi‑protected environments, while stainless steel enclosures are specified for coastal outdoor installations, industrial washdown areas, and locations prone to moisture exposure. Enclosure protection ratings can include IP44, IP54, IP65, and IP66 depending on the degree of dust and water ingress protection required for the site conditions.
The internal configuration of a 400A Distribution Box from Jiaxing Huizhi can include:
Main 400A MCCB as the incoming feed connector
Individual outgoing MCCBs or RCBOs for sub‑circuit protection
Residual current protection devices for personnel safety
Surge protection devices to protect against transient overvoltages
Digital voltmeters and ammeters for real‑time monitoring
Neutral and earth busbars sized for 400A load capacity
Cable entry glands and strain relief assemblies designed for heavy‑gauge cable routing
The company's 400A Distribution Boxes are used in specific electrical workflows such as:
Construction Site Temporary Power Distribution: Boxes receive power from a main utility feed or generator and distribute to site lighting, welding equipment, hoists, and portable compressors.
Commercial Building Electrical Rooms: Distribution of service entrance power to sub‑panels serving HVAC units, escalators, elevators, and tenant power systems.
Generator Backup Power Systems: Integration with backup generator sets to provide protected power distribution for critical loads during mains interruptions.
Industrial Machinery Installations: Distribution of medium‑voltage panel output to motor drives, pump systems, heating loads, and control panels.
APEKS ELECTRICsupports OEM and ODM solutions, allowing customers such as electrical contractors, rental equipment companies, project developers, and systems integrators to specify panel layouts, protection device types, interconnection wiring standards, and labeling schemes. The company's engineering team assists with load calculations, protection coordination studies, schematic design, and enclosure selection based on environmental conditions. Before shipment, products undergo electrical testing including insulation resistance measurement, continuity verification, functional testing of breakers and protective devices, and mechanical inspection to ensure compliance with project documentation.
Jiangsu PTh
Jiangsu PTh manufactures 400A Distribution Boxes intended for commercial and industrial power distribution. Panels are designed with powder‑coated steel enclosures and modular busbar systems. Protection configurations include MCCBs, RCBOs, and surge modules. Typical applications include construction site power management, temporary power feeds for industrial shutdowns, and commercial building service distribution.
Zhejiang ECl
Zhejiang ECl supplies portable 400A Distribution Boxes used in event power systems, outdoor concerts, exhibition centers, sports event venues, and mobile power installations. Enclosures include powder‑coated steel options with IP54 ratings. Protection components include residual current devices and molded case breakers.
Shanghai Etpl
Shanghai Etpl offers medium to high amperage power distribution solutions including 400A Distribution Boxes customized with metering systems, breaker panels, and cable management features. Panels serve trade show installations, mobile generator hookups, and temporary power infrastructures.
Wenzhou PSyts
Wenzhou PSyts produces IP65‑rated 400A Distribution Boxes equipped with industrial sockets, main breakers, and surge protection. Products are used for multi‑machine power feeds on sites such as construction projects, testing facilities, and industrial maintenance shutdowns where multiple circuits must be powered simultaneously.
Nanjing SfPr
Nanjing SfPr manufactures distribution panels including 400A systems with configurable outgoing breaker arrangements. Panels are suitable for factory maintenance power distribution, generator backup systems, and temporary power networks for construction.
Guangzhou ETh
Guangzhou ETh focuses on power distribution solutions for entertainment industry applications such as outdoor concerts, festival power infrastructure, broadcast site power management, and temporary stage installations. 400A boxes can be configured with multiple circuit protection devices and digital monitoring.
Kunshan PFlow
Kunshan PFlow supplies 400A Distribution Boxes with galvanized steel and aluminum alloy enclosures designed for mobile power systems, industrial facilities, and construction projects. Custom internal layouts support breaker placement and cable routing.
Tianjin ElSf
Tianjin ElSf produces portable distribution systems designed for electrical contractors and rental applications. Its 400A Distribution Boxes incorporate molded case breakers, surge protection, and cable entry systems suited for outdoor installation and temporary power applications.
Shandong ClPr
Shandong ClPr supplies 400A Distribution Boxes engineered for project power distribution including generator hookups, site power management, and industrial panel feeds. Panels support configurable outgoing circuits and surge protection devices.
Understanding 400A Distribution Boxes
A 400A Distribution Box functions as a centralized power management system that receives a 400A feeder supply and distributes electrical power to sub‑circuits through protective devices. Primary components typically include:
Incoming 400A MCCB or main switch
Copper busbar system sized for 400 amps
Outgoing MCCBs or RCBOs configured for sub‑circuits
Residual current protection for personnel safety
Surge protection modules for transient control
Industrial sockets or panel outlets
Digital voltmeters and ammeters for monitoring
Cable glands with strain relief for heavy gauge cables
The 400 amp rating allows the system to handle multiple load centers simultaneously. Actual capacity and configuration depend on voltage level, cable sizing, protection coordination, and local electrical standards.
In construction environments, distribution boxes receive utility or generator power and distribute to equipment such as welding rigs, concrete mixers, cranes, lighting circuits, and site offices. In commercial buildings, they serve as service entrance distribution points feeding sub‑panels for HVAC units, elevators, and tenant power feeds. In industrial settings, distribution boxes support maintenance power, temporary installations for commissioning tests, and segmented power delivery for process units.
Why APEKS ELECTRIC CO., Ltd. Should Be Considered
APEKS ELECTRIC CO., Ltd.differentiates itself by providing project‑oriented distribution solutions tailored to specific load requirements, environmental conditions, and protection needs. Its engineering consultation services assist clients with load calculations, breaker selection, panel layout, enclosure protection rating, and compliance documentation. Through OEM and ODM programs, the company supports custom branding, labeling, panel configuration, and cabling layouts according to client specifications. The company also provides technical support during installation, commissioning, and post‑deployment troubleshooting.
By integrating electrical design, production planning, quality control, and customer support, APEKS ELECTRIC ensures that its 400A Distribution Boxes are aligned with the requirements of construction site temporary power, commercial building service distribution, and industrial power management systems. The company also supports export preparation, documentation, and logistics coordination to facilitate international project deployments.
This article serves as a comprehensive overview of 400A Distribution Box suppliers in China for buyers seeking medium‑to‑high amperage power distribution solutions in 2026 and beyond.
