China Distribution Box Manufacturers Suppliers Factory - Quotation

What Is a Distribution Box and Why It Matters

A distribution box is the central hub of an electrical system. It receives incoming power from the mains supply or a downstream transformer, divides it into multiple subsidiary circuits, and protects every circuit with a breaker or fuse. In factories, commercial buildings, residential complexes, solar power plants, and street lighting systems, the distribution box decides how safely, reliably, and conveniently power is delivered to the load - and how quickly a fault is localized and isolated.

We designs and builds distribution boxes that go beyond a catalog part number. Every distribution box is engineered to the specific environment (indoor / outdoor / coastal / solar / mining), specific load profile (lighting / motor / PV string), and specific grid standard of the destination market. As a source factory, we control sheet-metal processing, electrostatic powder coating, copper busbar bending, breaker integration, and final routine testing under one roof - giving you factory-direct distribution box prices with full OEM flexibility.

How Does a Distribution Box Work?

The operating principle of every distribution box follows the same power flow - regardless of whether it serves a household lighting circuit or a 100 MW solar plant:

Incoming supply

transformer / utility main

Main switch / isolator

complete shut-off

Main circuit breaker

incomer protection

Copper busbar

power split

Outgoing breakers

MCB / MCCB / RCBO

Load circuits

lighting · motors · sockets · PV

Step by step:

The main feeding cable enters the distribution box and lands on the main switch or main breaker.

From there, power flows onto the busbar - a copper bar that distributes the incoming current to each outgoing way.

Every outgoing circuit has its own breaker sized to the cable it protects, plus optional RCD / RCBO earth-leakage protection and SPD surge protection.

When a fault occurs, only the affected breaker trips; every other circuit keeps running, so a fault is isolated in seconds without blacking out the whole building.

BWX Photovoltaic Grid-Tied Combiner Box
A professional solar PV AC combiner cabinet connecting string inverters to AC distribution cabinets or step-up transformers. Integrates circuit breaker protection, surge protection, energy metering,
XM Electric Energy Meter Box
A durable stainless steel enclosure for residential, commercial, and industrial energy metering. Available in wall-mounted and floor-standing types with overload, short circuit, overvoltage, and
PV Combiner Box
Solar DC combiner box for photovoltaic systems. Consolidates multiple PV string outputs into a single inverter feed with overcurrent protection, surge protection (SPD), and string monitoring. IP65
XL-21 Power Distribution Cabinet
Low voltage AC 500V power distribution cabinet for industrial plants, mining enterprises, and high-rise buildings. IEC 61439-1 compliant, IP30 protection, rated current up to 630A.
Solar Grid Connection Box
PV on-grid distribution box connecting your solar inverter to the utility grid. Features anti-islanding protection, overvoltage/undervoltage monitoring, surge protection, overcurrent protection, and
JP Outdoor Integrated Distribution Box
JP Outdoor distribution box integrating metering, outgoing feeders, and reactive power compensation with short-circuit, overload, overvoltage, and leakage protection. Rated for 30–400 kVA
JXF Low Voltage Distribution Box
Wall-mounted cold-rolled steel enclosure for indoor and outdoor power distribution. Rated up to 400A, IP54 protection, electrostatic epoxy coating, DIN-rail compatible. 40+ standard sizes with full
Power Distribution Box
Factory-direct power distribution boxes rated 16A to 6300A.. IEC 61439 certified, IP54-IP66 protection, fully customizable for your industrial, commercial, or infrastructure project. . Get
Electrical Distribution Box
An Electrical Distribution Box is the heart of any electrical system. It receives power from the main supply and divides it into multiple subsidiary circuits — each protected by a circuit breaker or
Photovoltaic Grid-Connected Cabinet
The Photovoltaic Grid-Connected Cabinet is a critical power distribution unit that connects the solar photovoltaic array to the electrical grid.

Types of Distribution Boxes We Manufacture

Every installation environment demands a different distribution box. As a factory, we build them all under one roof. Below are the seven distribution box families we currently produces for the global market.

JXF Low-Voltage Distribution Box

The workhorse of LV power distribution. Wall-mounted or floor-standing, 380 / 400V three-phase, with main breaker + MCCBs, multifunction meter, and SPD surge protection.

JXF PV Grid-Parallel Distribution Box

Single-phase / three-phase photovoltaic grid-connected distribution box (with meter position). Designed for safe interconnection of rooftop solar to the utility grid, IEC compliant.

GGD Photovoltaic Grid Metering Cabinet

High-power industrial and commercial PV grid-connected metering distribution cabinet. Integrates meter, protection, and anti-backflow control. Cold-rolled steel enclosure.

DFW-35 kV European Cable Junction Box

European-style cable distribution box for 35 kV power distribution networks. Three-phase wall-mounted, IP33, suitable for cable joint + tee-off + branching applications.

Integrated Smart Distribution Box

All-in-one intelligent power distribution box with AC / DC outputs, lithium battery backup (51.2V/100Ah), 1000W inverter, 10-inch split display, 5G / WiFi / CAN / RS485 communication.

PV-DC Photovoltaic Combiner Box

Combines 2–24 PV strings with fusing, surge protection, DC isolator, and optional monitoring. IP65 outdoor rating, lightning protection class I/II as standard.

Main Components Inside a Distribution Box

The exact configuration changes with the application, the installation environment, and the local electrical standard - but these are the twelve components found in almost every distribution box we build:

Component	Typical Rating / Form	Function in the Distribution Box
Enclosure	Cold-rolled steel / SS304 / SS316 / ABS	Protects components from dust, water, impact, and accidental contact; defines the IP rating
Main switch / isolator	63 – 630 A	Disconnects the entire distribution box from the supply for maintenance and emergency shut-off
Main circuit breaker	MCCB, 100 – 630 A	Protects the incomer cable against overload and short circuit
Busbar	Copper, tin-plated	Distributes incoming current to all outgoing ways - we never substitute aluminum or downsize
MCB / MCCB breakers	1 – 630 A per way	Protect each outgoing circuit; MCCBs used for larger motor / feeder loads
RCCB / RCBO	30 / 100 / 300 mA	Residual-current (earth-leakage) protection against electric shock; RCBO combines leakage + overcurrent in one way
Surge protective device (SPD)	Class I / II / III	Clamps lightning and switching transients - essential for outdoor and PV distribution boxes
Neutral bar & earth bar	Copper	Termination points for neutral and protective-earth conductors of every circuit
Metering & monitoring	Multifunction meter / CTs	Voltage, current, power, energy reading; optional RS485 / Modbus for remote monitoring
Contactors & relays	Per motor way	Motor starting / stopping, interlocks, and automated control circuits
DIN rail & mounting plate	35 mm DIN	Standardized mounting for MCBs, RCBOs, meters, and terminal blocks
Terminal blocks & glands	Per cable size	Organize incoming / outgoing wiring and match conduit or cable entry sizes

Types of Distribution Boxes - The Complete Classification

Distribution boxes are classified along three dimensions: their position in the electrical system, their application, and their material & installation method. In real projects the categories overlap - a JP outdoor distribution box, for example, is simultaneously an outdoor box, a steel box, and a main/sub distribution box. Here is the full picture:

1. By Position in the Electrical System

Type	Role in the system
Main distribution box (MDB)	Receives the main low-voltage supply from the transformer or switchgear and distributes it to sub-distribution boxes, large equipment, or major building zones. Highest current rating in the chain (up to 630 A+).
Sub distribution box (SDB)	Sits downstream of the MDB and feeds one floor, workshop, zone, or equipment group. Often a main-lug panel protected by the upstream breaker.
Final distribution box	The last stage before the load - home consumer units, lighting distribution boxes, and socket boxes. Typically 4 – 24 ways of MCB / RCBO.

2. By Application

Residential

Lighting & Socket Distribution Box

4 – 24 ways for lighting, sockets, and household appliances. MCB + RCBO per circuit, compact surface or flush-mount enclosure, IP30 – IP40.

Commercial

Commercial Distribution Box

Offices, retail, hotels, schools: zone-based lighting, HVAC, and socket circuits with metering and scheduled control via contactors or lighting relays.

Industrial

Motor Control Distribution Box

Combines distribution with motor starting: contactors, thermal overloads, MPCBs, star-delta or soft-start circuits, local / remote control, and status indication.

Outdoor

Outdoor Distribution Box

JP-style integrated boxes for street lighting, irrigation, and rural distribution. IP54 – IP65, SS304 or galvanized enclosure, rain canopy, anti-condensation heater.

Solar

PV Combiner & Grid-Tie Box

DC combiner (1000 / 1500 V, 2 – 24 strings) plus AC grid-connection cabinet with anti-backflow and metering - the solar-specific distribution box family.

Temporary

Site / Temporary Power Distribution Box

Construction-site and event distribution: rugged enclosure, socket outlets, RCD protection on every way, portable or skid-mounted.

Distribution Box Specifications at a Glance

All distribution boxes are routine-tested before shipment. Material certificates (cold-rolled steel, SS304, copper busbar) and routine test reports ship with every order. Third-party inspection (SGS / BV / TÜV) is welcome before delivery.

Parameter	JXF LV Box	GGD PV Metering	JP Outdoor Box	PV Combiner Box	DFW-35kV Junction
Rated voltage	380 V / 400 V	AC 380V	380 V	1000 V / 1500 V DC	35 kV
Rated current	63 – 630 A	250 – 800 A	63 – 400 A	per string 15 – 20 A	630 A
Short-time withstand	10 – 50 kA / 1s	15 – 30 kA / 1s	10 – 30 kA / 1s	-	20 kA / 2s
Protection degree	IP30 – IP54	IP30 – IP54	IP54 – IP65	IP65	IP33
Enclosure	Cold-rolled steel / SS304	Cold-rolled steel	SS304 / galvanized steel	Cold-rolled steel / SS304	Cold-rolled steel
Surface treatment	RAL 7035 powder coating	RAL 7035 powder coating	RAL 7035 / SS natural	RAL 7035 powder coating	RAL 7035 powder coating
Busbar	Copper (tin-plated)	Copper (tin-plated)	Copper (tin-plated)	- (fused)	Copper (tin-plated)
Ambient temperature	-25 to +40 °C	-25 to +40 °C	-40 to +60 °C	-25 to +60 °C	-40 to +40 °C
Humidity	≤ 90% (no condensation)	≤ 90% (no condensation)	≤ 95% (no condensation)	0 – 95%	≤ 95% (daily avg ≤ 90%)
Altitude	≤ 2000 m	≤ 2000 m	≤ 2000 m	≤ 2000 m	≤ 1000 m
Standards	IEC 61439, GB 7251	IEC 61439, GB 7251	IEC 61439, GB 7251	IEC 61439, GB/T 34936	IEC / GB 35kV standard
Certifications	CE, ISO 9001	CE, ISO 9001	CE, ISO 9001	CE, ISO 9001	CE, ISO 9001, type test

Choosing the Right Distribution Box by Environment

A wrong distribution box selection is the #1 cause of premature failure. Use this decision matrix to match your installation environment to the right distribution box family.

Indoor-Factories, Commercial Buildings, Residential

Recommended: JXF wall-mounted distribution box or XL-21 floor-standing
Protection: IP30 – IP54 is sufficient
Enclosure: cold-rolled steel with RAL 7035 powder coating
Key features: clear circuit labeling, neat wiring, breaker accessibility, multi-function meter

Outdoor-Coastal, Desert, High-Humidity

Recommended: JP integrated distribution box with rain canopy
Protection: IP54 – IP65 (mandatory for outdoor)
Enclosure: SS304 / galvanized steel, double-door sealing, anti-condensation heater
Key features: salt-fog resistance, UV-resistant paint, vent plug, drainage hole

Solar PV-Utility-Scale & Commercial Rooftop

DC side: PV combiner box (1000V / 1500V), 2–24 strings, SPD Class I/II
AC side: PV grid connection cabinet with anti-backflow and metering
Protection: IP65 outdoor rating mandatory
Key features: DC isolator switch, string monitoring, lightning protection, RS485 / Modbus

Utility & Rural Grid-35 kV Cable Networks

Recommended: DFW-35 kV European-style cable junction box
Function: cable joint, tee-off, branching for 35 kV power distribution
Protection: IP33 indoor/outdoor
Key features: rated current 630A, short-time withstand 20 kA / 2s, suitable for wall-mounted installation

Distribution Box Standards We Comply With

International (IEC)

IEC 61439-1 - Low-voltage switchgear and controlgear assemblies: General rules (the core distribution box standard)
IEC 61439-2 - Power switchgear and controlgear assemblies
IEC 61439-3 - Distribution boards intended to be operated by ordinary persons (DBO)
IEC 61439-4 - Assemblies for construction sites (ACS)
IEC 61439-5 - Assemblies for power distribution in public networks (PBD)
IEC 60529 - Degrees of protection provided by enclosures (IP code)
IEC 62208 - Empty enclosures for low-voltage switchgear and controlgear assemblies

Chinese National (GB / GB-T)

GB 7251.1 - Low-voltage switchgear and controlgear assemblies: General rules

GB 7251.3 - Distribution boards (DBO)

GB/T 34936 - Photovoltaic DC combiner-box technical specification

GB 4208 - Degrees of protection provided by enclosures (IP code)

GB/T 20641 - Empty enclosures for low-voltage switchgear

Distribution Box vs Distribution Board vs Electrical Panel vs Junction Box

Buyers from different regions use different words for the same equipment - and some words that sound similar are not interchangeable. This table clarifies the terminology before you send us an inquiry:

Term	What it means
Distribution box / DB box	The enclosure that splits one incoming supply into multiple protected outgoing circuits. The standard term in IEC markets and the one we use throughout this page.
Distribution board	Functionally identical to a distribution box - "DB" or "distribution board" is simply more common in UK / Commonwealth / IEC-market specifications.
Electrical panel / breaker panel	A broader North-American term covering distribution, protection, and control assemblies. A distribution box is one type of electrical panel.
Consumer unit / fuse box	Residential distribution box terminology (UK / older installations) - the final distribution box feeding home lighting and socket circuits.
Junction box	Protects cable joints and tee-offs only - it contains no breakers and cannot replace a distribution box. (We supply these too: IP65 SS304 / SS316.)
Terminal box	Provides termination points for motor or instrument wiring; no circuit-protection function.
Switchgear cabinet	The higher-rated upstream assembly (typically 12 – 40.5 kV) at the transformer output. See our switchgear cabinet range - the natural upstream partner of every distribution box.

Sizing a Distribution Box - Circuits, Ways, and Future Expansion

Beyond the environment, three numbers decide your distribution box size:

Decision	Rule of thumb
Number of ways (circuits)	Count your load circuits, then add 20 – 30% spare ways for future expansion. Standard ways: 4 / 6 / 8 / 12 / 18 / 24 / 30 / 36+ (JXF / XL-21 enclosures grow with way count).
Incomer rating	Sum of all outgoing circuits × diversity factor (typically 0.7 – 0.9), rounded up to the next standard MCCB rating: 63 / 100 / 160 / 250 / 400 / 630 A.
Protection level per way	MCB only for lighting / socket ways; RCBO where personnel contact the equipment (30 mA); MCCB + contactor + thermal overload for motor ways; SPD Type 1+2 at the incomer for outdoor / PV distribution boxes.

Not sure how to size it? Send your load list - even a rough one - and our engineers will return a complete distribution box configuration (ways, breaker ratings, busbar size, enclosure dimensions) within 24 hours, free of charge.

Why Choose us?

Factory-Direct Pricing

We manufacture the enclosure, bend the copper busbar, and assemble the distribution box - all in one factory. No trading-company markup.

Full OEM / ODM

Non-standard dimensions, custom circuits, your brand and labeling. We adapt the distribution box to your drawing, not the other way around.

Copper Busbar & Branded Components

No aluminum or downsizing. 100% copper busbar as standard. Branded breakers / meters (CHINT, Delixi, ABB, Schneider optional).

Multi-Environment Expertise

Indoor, outdoor, coastal, solar, mining, tropical, desert - we have shipped to all of them and know what fails first in each.

One-Stop Electrical Supplier

Pair your distribution box with our switchgear cabinet and transformer from the same factory - single PO, single FAT, single freight.

Seaworthy Packing & Fast Delivery

Export-standard plywood cases, reinforced brackets, vacuum packaging. Door-to-door logistics with 30+ established freight forwarders.

Need a Distribution Box Price List Today?

Send us your schematic drawing, required quantity, and destination port. Our sales engineer will reply with a complete quotation within 24 hours - including FAT plan, packing list, and sea freight estimate. Free wiring review by our engineers included.

Email Our Distribution Box Team

FAQ

1. What is the difference between a distribution box and a switchgear cabinet?

A distribution box is the final, end-of-line enclosure that distributes power to specific loads (lighting circuits, motor starters, PV strings, etc.) - typically rated 380 / 400V and below 1000A. A switchgear cabinet is a higher-rated assembly (often 12kV+) used at the transformer output or upstream of the distribution box. They are complementary products in the same power distribution chain.

2. What is a PV combiner box, and how many strings can it combine?

A PV combiner box is a DC-side distribution box used in solar power plants. It combines 2 to 24 PV strings (typical configurations: 8 / 12 / 16 / 20 / 24-in / 1-out), with DC fuse protection, surge protection, DC isolator, and optional string monitoring. Ratings: 1000V DC (residential / commercial) and 1500V DC (utility-scale).

3. Can I use a JXF distribution box outdoors?

A standard JXF is rated IP30 – IP54 and is intended for indoor / sheltered installation. For outdoor or wet environments, choose the JP integrated distribution box (IP54 – IP65) with rain canopy, double-door sealing, and SS304 enclosure. We also offer IP65 stainless-steel weatherproof junction boxes for cable termination in coastal sites.

4. What is a JP outdoor integrated distribution box?

The JP distribution box integrates metering, distribution, protection, and reactive power compensation in one outdoor-rated enclosure. It is widely used in rural grid upgrading, agricultural irrigation, and street lighting systems. Standard rating: 380V, 63–400A, IP54 – IP65, with options for SS304 enclosure.

5. What is the difference between DFW-12 and DFW-35 kV cable junction boxes?

DFW-12 is a 12 kV European-style cable junction box for medium-voltage cable networks. DFW-35 is rated 35 kV and is used in 35 kV primary distribution networks. Both are wall-mounted, use European-style bolted cable connectors, and conform to DIN47636 / equivalent standards. Rated current 630A, short-time withstand 20 kA / 2s.

Henan GNEE Electric Co., Ltd. is one of the most professional distribution box manufacturers and suppliers in China, also supports customized service. Welcome to buy durable distribution box in stock here and get pricelist from our factory. We also accept customized orders.

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