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🏭 Verified Combiner Box Manufacturer & Supplier

Solar Combiner Box
Manufacturer
& Factory

ShineTong designs and manufactures a complete line of PV combiner boxes — DC string boxes (1000V / 1500V), AC distribution boxes, integrated DC&AC combined boxes, and EPS battery boxes — for residential, C&I, and utility-scale solar projects in 70+ countries. CE/UL/TÜV certified, OEM/ODM available.

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15+
Years Manufacturing
2–36
String Ways Covered
1500V
Max DC System Voltage
IP65
Weatherproof Standard
ShineTong solar PV combiner box installed at utility-scale ground mount array
1000V / 1500V DC System Voltage
Technology Overview

What Is a Solar Combiner Box? The Complete B2B Primer

A solar combiner box — also called a PV string box, array junction box (AJB), or DC combiner — is an enclosure installed between the PV array strings and the inverter's DC input. Its fundamental job is to aggregate multiple parallel strings of solar panels into one or more combined DC outputs, reducing the number of cables running to the inverter and providing a single, protected interface point for the entire array.

Inside a well-engineered combiner box you find string-level overcurrent protection (DC fuses or DC MCBs), a Type 2 DC surge protective device (SPD) to handle lightning transients, a main DC disconnect switch or MCCB, a copper busbar system for string consolidation, and — in monitoring-equipped models — a current measurement board with RS485 Modbus communication to report per-string production data to the inverter or plant SCADA system.

For B2B buyers — EPC contractors, solar distributors, and system integrators — choosing the right combiner box specification (voltage class, string count, fuse vs. MCB, monitored vs. unmonitored) significantly impacts system BOS cost, O&M efficiency, and long-term yield assurance. ShineTong's modular product range covers every project size from a 6-string residential system to a 36-string utility-scale block.

⚡DC String Fuses (IEC 60269-6)
🛡️Type 2 DC SPD (IEC 61643-31)
🔌DC MCB / Disconnect Switch
📊String Monitoring (RS485)
🔧Copper Busbar Assembly
🔒MC4 / Cable Gland Entry
System Architecture

How a PV Combiner Box Works in a Solar Array

Understanding the signal and power flow through the combiner box helps you specify the correct ShineTong model and communicate its value to your EPC and O&M customers.

String DC Input

Each PV string — a series chain of panels — connects to its dedicated input terminal via MC4 connectors or cable glands. Voltage depends on string length; current depends on irradiance and panel Isc.

Fuse / MCB Protection

Each string passes through an individual DC-rated fuse (IEC 60269-6) or resettable MCB. If a string fault, reverse current, or ground fault occurs, only that string is isolated — protecting panels, cables, and the inverter from damage.

Busbar Aggregation & SPD Clamping

Protected strings connect to copper positive and negative busbars, combining current from all strings into a single output. The Type 2 DC SPD monitors across the busbars and clamps any lightning-induced voltage spike to a safe level (Up ≤ 4.0 kV), diverting surge energy to the PE ground rail.

Output to Inverter & Monitoring

Combined DC power passes through the main disconnect/MCCB to the inverter input. In monitored models, a current board measures per-string Idc via Hall sensors and transmits data via RS485 Modbus to the inverter or external SCADA for real-time fault detection and yield analysis.

Product Catalog

ShineTong Combiner Box Series

Our combiner box range addresses every PV system topology — from small residential DC string boxes to three-phase commercial AC distribution and fully integrated DC&AC units. All models carry IP65, Anti-fire, Anti-UV, Anti-impact, and Anti-corrosion ratings, manufactured in our ISO-certified Guangdong factory.

ShineTong ST-DCJB DC combiner box 1000V string box
DC Combiner
Residential & C&I · 1000V / 1500V DC
ST-DCJB Series
1–6 string inputs, 1–2 outputs. Fuse or MCB equipped. Optional string monitoring via RS485 Modbus.
System Voltage
1000V / 1500V DC
String Ways
1–6 In / 1–2 Out
Fuse Rating
10A / 15A DC
Protection
IP65
CEULTÜVSAA
Inquire →
ShineTong ST-DCJB-L large combiner box 16-36 string utility scale
DC Multi-String
C&I & Utility Scale · 1000V / 1500V DC
ST-DCJB-L Series
Up to 36 string inputs. Integrated SPD 40kA Type 2. Main MCB 63A–125A. Wall or pole mount.
String Ways
Up to 36 Strings
SPD
40kA Type 2
Main MCB
63A / 125A
Monitoring
RS485 Modbus opt.
CEULTÜV
Inquire →
ShineTong ST-ACDB AC combiner box distribution box three phase
AC Combiner
Residential & Light Commercial · AC
ST-ACDB Series
Single-phase (S3, S6) and three-phase (T10, T20) AC distribution. Ideal downstream of microinverters or string inverters.
Models
S3 / S6 / T10 / T20
Phase
1-Phase / 3-Phase
AC Circuits
3 to 20 Ways
Protection
IP65 / Anti-UV
CECBSAA
Inquire →
ShineTong ST-DCACJB integrated DC and AC combiner box single enclosure
DC & AC Combined
Residential & C&I · All-in-One
ST-DCACJB Series
Integrates DC string combiner and AC distribution in a single enclosure. Models: 1-1/S3, 2-2/S6, 2-2/T10, 2-2/T20. Reduces BOS cost and installation space.
DC In / Out
1–2 / 1–2 Strings
AC Circuits
3 / 6 / 10 / 20 Ways
System V
1000V DC / AC 230V
Enclosure
IP65 Single Box
CEULSAA
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ShineTong ST-EPS emergency power supply battery box for solar storage
EPS / Battery Box
Energy Storage Integration
ST-EPS Box Series
Emergency Power Supply (EPS) box for residential and C&I solar-plus-storage systems. Integrates battery disconnect, SPD, and load switching in a single weatherproof unit.
Application
Solar + Storage
Battery V
48V–500V DC
Functions
Disconnect + SPD
Protection
IP65
CECBSAA
Inquire →
ShineTong ST-DCJB-M smart monitored string combiner box RS485 data logging
Smart Monitored
C&I & Utility · Intelligent
ST-DCJB-M Smart Series
All features of ST-DCJB-L plus integrated current monitoring board, digital LCD display, and RS485 Modbus RTU output for per-string yield analysis.
Monitoring
Per-String Current
Display
LCD Digital Panel
Comms
RS485 Modbus RTU
Alert
Under-current alarm
CEULTÜV
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📋 Download Full Combiner Box Catalog
Technical Advantages

Why ShineTong Combiner Boxes
Outperform Generic Alternatives

These engineering choices directly impact array uptime, fault isolation speed, O&M cost, and the long-term profitability of your customers' solar assets.

⚡

DC-Rated Fuses Certified to IEC 60269-6

Standard AC fuses cannot reliably interrupt DC fault currents because DC arcs do not self-extinguish at zero-crossings. ShineTong combiner boxes exclusively use IEC 60269-6 PV-specific DC fuses, capable of interrupting fault currents at 1000V and 1500V DC. Each fuse is individually mounted in a touch-safe, finger-protected carrier — reducing the risk of electrical shock during fuse replacement while minimizing system downtime to a single string.

🌩️

Type 2 SPD Certified to IEC 61643-31

ShineTong combiner boxes incorporate Type 2 DC Surge Protective Devices rated to 40 kA (10/350 µs waveform), certified to IEC 61643-31 — the photovoltaic-specific DC SPD standard. This matters because PV DC SPDs must handle continuous DC follow current after a surge event, which AC SPDs are not designed for. Proper SPD specification is one of the most commonly overlooked quality differences between budget and professional-grade combiner boxes.

🔬

Per-String Current Monitoring (Optional)

The optional ST-DCJB-M Smart Series integrates Hall-effect current sensors on each string input, continuously measuring string Idc. The built-in monitoring board compares each string's output against a configurable threshold and triggers an RS485 Modbus alarm when a string falls below the expected level — detecting soiling, shading, module degradation, or wiring faults weeks before they appear on inverter-level yield analysis, enabling proactive O&M that your customers value.

🧱

Anti-Fire, Anti-UV, Anti-Impact Enclosure

ShineTong combiner box enclosures are manufactured from UL94 V-0 flame-retardant thermoplastic or powder-coated steel, UV-stabilized to resist solar degradation for 20+ year outdoor service life. The enclosure wall thickness and gasketing achieve IP65 protection — dust-tight and jet-water resistant. Lock mechanisms are stainless steel or zinc-alloy to prevent corrosion in coastal and tropical environments, where lesser enclosures fail within 2–3 years of deployment.

🔧

Tool-Free MC4 String Entry & DIN Rail Components

All ShineTong DC combiner boxes accept MC4-compatible connectors at the string input terminals, enabling plug-and-play connection without additional tools during installation — reducing commissioning labor by up to 40% compared to bare-wire cable gland entries. Internal components (fuse holders, MCBs, SPDs, busbars) are mounted on standard DIN rails with finger-safe terminal covers, allowing component replacement in the field without removing the enclosure from its mounting bracket.

📐

Modular Configuration: 2 to 36 String Ways

Unlike fixed-configuration competitors, ShineTong's combiner box architecture supports field configuration of string count (2 to 36 ways), fuse or MCB protection type, monitored or unmonitored, and single or dual output. This flexibility lets EPC contractors standardize on a single supplier SKU while customizing for each project's inverter input configuration, significantly simplifying procurement, reducing inventory carrying cost, and enabling faster project delivery across a varied project portfolio.

Specifications

Key Technical Parameters

1500V
Maximum DC system voltage (utility-scale models)

Engineered for Real-World Field Conditions

ShineTong combiner boxes are rated for -25°C to +60°C ambient operating temperature, covering both sub-arctic installations and high-temperature desert environments. Copper busbars are tin-plated to prevent oxidation and maintain low contact resistance over a 25-year service life. All cable entry glands are PG-type with IP65-rated sealing rings, preventing water ingress even after 10+ years of thermal cycling.

40kA
SPD surge withstand rating (Type 2 DC, IEC 61643-31)
Parameter ST-DCJB (DC) ST-ACDB (AC) ST-DCACJB (Combo)
System Voltage1000V / 1500V DC230/400V AC1000V DC + AC
String Ways1–36 inputs3–20 circuits1–2 DC + 3–20 AC
Per-String Fuse10A / 15A DCN/A (MCB)10A / 15A DC
SPD Rating40kA Type 2 DC20kA Type 2 AC40kA DC + 20kA AC
Main Disconnect63A / 125A MCCB32A – 100A MCB63A DC + 32A AC
MonitoringOptional RS485N/AOptional RS485
Enclosure RatingIP65IP65IP65
Flame RatingUL94 V-0UL94 V-0UL94 V-0
Cable EntryMC4 / PG GlandPG GlandMC4 + PG Gland
Busbar MaterialTin-plated CuTin-plated CuTin-plated Cu
Operating Temp-25°C ~ +60°C-25°C ~ +60°C-25°C ~ +60°C
MountingWall / PoleWallWall
CertificationsCE/UL/TÜV/SAA/CBCE/CB/SAACE/UL/SAA/CB
Global Compliance

Certified Across International Markets

ShineTong combiner boxes carry third-party certifications from the world's most respected testing bodies, ensuring legal compliance and bankability in your target market — critical for project financing and EPC contract compliance.

🇪🇺
CE Mark
EU Low Voltage Directive (LVD), EMC Directive, and RoHS compliance. Required for legal sale across all 27 EU member states and EEA countries. Covers IEC 62109-1 PV safety standard.
🇺🇸
UL Listed
Underwriters Laboratories listing to UL 1741 and relevant ANSI standards. Required for grid-tied PV systems in the United States and Canada, and increasingly mandated by project lenders for bankable system design.
🇩🇪
TÜV Certified
TÜV Rheinland or TÜV SÜD component safety certification, widely respected by European EPCs, project developers, and insurance underwriters as a mark of independent third-party quality verification.
🌏
SAA / CB Scheme
Standards Australia SAA certification for Australian and New Zealand markets. CB Scheme mutual recognition certificate enables efficient market access across 57 participating countries in the IEC CB testing program.
Market Segments

Applications Across Every
Solar Installation Category

From residential rooftop arrays to multi-megawatt ground-mount facilities, ShineTong combiner boxes serve as the critical interconnection and protection layer in solar projects of every scale and market.

Residential rooftop solar combiner box installation
Residential

Home Rooftop Systems

ST-DCJB 2–8 string · DC&AC combo box · Compact wall-mount installation

Commercial and industrial rooftop solar combiner box C&I project
Commercial & Industrial

C&I Rooftop & Carport

ST-DCJB-L 8–24 string · 1000V/1500V · String monitoring · SCADA integration

Utility-scale ground mount solar farm combiner box installation
Utility Scale

Ground Mount & Solar Farm

ST-DCJB-M 16–36 string · 1500V · Per-string monitoring · Pole or pad mount

Your Factory Partner

Why B2B Buyers Choose ShineTong
as Their Combiner Box Supplier

ShineTong combiner box manufacturing production line factory
🏭

Direct Factory Pricing — No Trading Company Markup

ShineTong is a vertically integrated manufacturer. We design, assemble, and test combiner boxes at our own Guangdong facility — no intermediaries, no agent margins. For distributors and EPCs sourcing hundreds of units per project, factory-direct pricing can reduce combiner box BOS cost by 20–35% vs. trading company suppliers at comparable quality levels.

🎨

OEM/ODM: Full Customization Under Your Brand

We manufacture combiner boxes under your brand identity — custom enclosure colors, silk-screen printing or laser-engraved brand marks, custom label packs, localized warning text, and proprietary wiring diagrams included in the documentation. Our engineering team supports mechanical customization for specific mounting configurations and non-standard string counts with NDA protection and full tooling ownership options.

📐

Engineering Support: BOM Review & Specification Assistance

Our applications engineers review your system design and recommend the optimal combiner box configuration — string count, voltage class, fuse vs. MCB, monitoring requirement — to match your inverter input specification and country market requirements. We provide customized single-line diagrams and product datasheets in the format your project EPC requires for permitting and grid connection applications.

📦

Flexible MOQ, Fast Delivery, Project-Ready Packaging

Trial orders from 20 units. Standard stock orders from 100 units with 2–4 week lead time. Project-specific orders are pre-labeled with project site references and packed per-inverter input to reduce contractor sorting time on site. We offer sea freight (FCL/LCL), air freight, and express courier with full export documentation including Certificate of Origin, packing list, and insurance.

Buyer's Guide

Combiner Box Procurement Knowledge
for B2B Solar Buyers

Critical technical and commercial knowledge every EPC contractor, distributor, and system integrator needs to make confident, code-compliant combiner box specification decisions.

How do I choose between 1000V and 1500V DC combiner boxes?
The choice is determined by your inverter's maximum DC input voltage and the string's open-circuit voltage at the coldest expected site temperature (Voc max = Voc(STC) × [1 + |αVoc| × ΔT]). Most residential and commercial string inverters today accept up to 1000V DC, requiring a 1000V DC combiner box. Utility-scale central inverters and 1500V-rated string inverters demand 1500V DC boxes. Always calculate Voc max at site minimum temperature — not STC — and add a 10% safety margin. ShineTong's engineering team can review your string configuration and recommend the correct voltage class for your specific project site and panel selection.
Fuse vs. MCB per-string protection: which should I specify?
DC PV fuses (IEC 60269-6) provide reliable one-time protection at lower cost and are preferred for fixed commercial and utility-scale installations where string faults are rare and planned maintenance windows allow fuse replacement. DC MCBs (miniature circuit breakers) are manually resettable after tripping, preferred for residential systems where frequent access makes MCB convenience worthwhile, or for installations with high soiling rates where nuisance trips are possible. ShineTong combiner boxes are available in both configurations — specify at order or request a mixed configuration for different project types within the same BOM. Fuse rating should be 1.5–2× the string's short-circuit current (Isc).
Do I need string monitoring, and what data does it provide?
String monitoring measures individual string DC current (Idc) using Hall-effect sensors and transmits the data via RS485 Modbus RTU to the inverter monitoring interface or a dedicated data logger / SCADA system. For residential systems under 15 kW, string monitoring is optional — the inverter's built-in diagnostics are often sufficient. For C&I systems above 50 kW and utility-scale plants, string monitoring delivers rapid fault detection (detecting a faulty string within hours vs. weeks on inverter-only analysis), accurate underperformance root-cause analysis (shading vs. soiling vs. degradation vs. wiring fault), and reduced O&M truck rolls — providing a measurable return on the monitoring premium, typically recovered within 1–2 years of improved yield.
What SPD parameters should I check on the datasheet?
When evaluating SPD specifications, check: (1) Certification standard — must be IEC 61643-31 for PV DC applications, not IEC 61643-11 (AC). (2) Maximum continuous operating voltage (Ucpv) — must exceed your combiner box's maximum DC voltage including temperature coefficient (≥1000V or ≥1500V as applicable). (3) Nominal discharge current (In) — typically 5–20kA. (4) Maximum discharge current (Imax) — typically 40kA for Type 2. (5) Voltage protection level (Up) — should be ≤4.0kV for 1000V systems. (6) Short-circuit current rating (Iscc) — must match the available fault current at the SPD installation point. ShineTong combiner boxes specify all of these parameters in the datasheet provided with every shipment.
When should I use an integrated DC&AC combiner box vs. separate boxes?
The integrated DC&AC combiner box (ST-DCACJB) is most cost-effective for residential and small C&I systems with 1–4 DC string inputs and up to 20 AC circuits, where the total system fits within a single enclosure without exceeding IP-rated heat dissipation limits. The single-enclosure approach reduces BOS cost (one mounting bracket, one cable entry assembly, lower installation labor), minimises footprint in space-constrained electrical rooms, and simplifies system documentation. Separate DC and AC boxes are preferred when DC string count exceeds 6, when DC and AC components need to be positioned at different physical locations on a large roof, or when the AC distribution panel needs to be inside a conditioned electrical room while the DC combiner is in the array field.
What routine maintenance does a PV combiner box require?
A properly installed ShineTong combiner box requires minimal but important periodic maintenance: (1) Annual visual inspection — check for enclosure seal integrity, corrosion at cable entries, and SPD status indicators (green = OK, red = failed, replace immediately). (2) Annual torque check — verify busbar connection torques with a calibrated torque screwdriver to IEC 60068 specifications (typically 2–5 Nm depending on terminal size) — thermal cycling causes connection creep. (3) Bi-annual IR thermal imaging — identify hot spots at fuse holders, busbar connections, and MCB terminals indicative of high-resistance connections or overloaded protection devices. (4) SPD replacement — replace immediately if status indicator shows fault, or proactively after a known lightning strike event near the array. Document all maintenance activities in your O&M system for warranty and performance guarantee records.
FAQ

Frequently Asked Questions

ShineTong is a vertically integrated manufacturer with our own production facility in Guangdong, China. We design PCB monitoring boards, assemble enclosure components, perform 100% hi-pot and insulation resistance testing in-house, and ship from our own warehouse. We are not a trading company — buyers are welcome to conduct in-person or video factory audits with our production management team before placing orders.
Yes. Combiner boxes are inverter-agnostic devices — they connect between the PV array and the inverter's DC input terminals using standard DC wiring and MC4-compatible connectors. The key specification requirement is that the combiner box's DC voltage class (1000V or 1500V) matches the inverter's maximum DC input voltage rating, and that the combined string count and current rating is within the inverter's MPPT input range. ShineTong's engineering team provides compatibility documentation for all major inverter brands including Huawei, SMA, Fronius, SolarEdge, Sungrow, Growatt, Goodwe, and others.
Sample and evaluation orders start at 20 units for catalog models. Standard stock orders begin at 50–100 units per SKU with a 2–4 week production lead time. Project-specific orders (custom string count, OEM labeling) require 3–6 weeks from BOM confirmation. For forecast-driven procurement, we offer blanket order agreements with monthly call-offs against a committed quarterly volume, which enables priority production scheduling and guaranteed supply for project delivery windows. Contact our sales team for project-specific lead time quotation.
Yes. The ST-DCJB-M Smart Series outputs string current data via RS485 Modbus RTU, which is the standard industrial communication protocol supported by virtually all commercial inverter monitoring gateways and data loggers. We provide the full Modbus register map with every monitored combiner box shipment. The monitoring board can be addressed as a Modbus slave device on the same RS485 bus as the inverter, enabling a single data logger to collect both inverter-level and string-level data. For custom SCADA integration, we provide register map documentation and example code snippets for common platforms.
ShineTong combiner boxes carry a 3-year product warranty against manufacturing defects and premature failure under normal operating conditions. Extended warranty options (5 years) are available for high-volume B2B partners under a distributor agreement. For replaceable consumable components (SPD modules, fuse cartridges), we maintain spare parts inventory and can dispatch replacement components within 48 hours to ensure system uptime. Our after-sales team provides failure analysis reports for any warranty claim within 10 business days, supporting your own customer reporting requirements.

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