PV Combiner Box Metal Shell for Solar PV Systems
EWJ manufactures solar combiner boxes and photovoltaic combiner boxes in galvanized steel and stainless steel for utility-scale plants, commercial rooftops and industrial PV installations. Every unit is built for outdoor service with a configurable string layout, surge protection and a metal housing that keeps the DC side protected for its service life.
Configure input string counts, mounting style, material and internal layout to match your project — from a 2-string rooftop box to a 36-string utility combiner.
Why a Metal PV Combiner Box
A solar combiner box is the boundary between the module field and the inverter. Everything downstream depends on how well that enclosure is built.
Technical Specifications
All values below are taken from the manufactured PV combiner box, not from a generic datasheet.
| Product name | Photovoltaic Combiner Box |
| Model series | EWJ-PV |
| Protection grade | IP65 (IP66 available) |
| System voltage | 1000V |
| Voltage protection level | 3.8kV |
| Nominal discharge current | 20kA |
| Input string options | 4 / 6 / 8 / 10 / 12 / 14 / 16 / 18 (2 to 36 strings available) |
| Material | Galvanized steel / stainless steel |
| Surface treatment | Powder coating |
| External dimensions | Custom per project |
| Installation method | Wall mounting (pole and floor standing available) |
| Access options | Anti-theft locking, optional viewing window |
| Thermal management | Natural ventilation, optional fan systems |
| Integration | Compatible with breakers, surge protectors and string monitoring devices |
Model Series by String Count
Standard input string configurations from 2 to 36 strings. Custom string layouts are available for non-standard module arrays.
| Model | Input strings |
|---|---|
| EWJ-PV2 | 2 |
| EWJ-PV4 | 4 |
| EWJ-PV6 | 6 |
| EWJ-PV8 | 8 |
| EWJ-PV10 | 10 |
| EWJ-PV12 | 12 |
| EWJ-PV16 | 16 |
| EWJ-PV18 | 18 |
| EWJ-PV24 | 24 |
| EWJ-PV36 | 36 |
Where PV Combiner Boxes Are Used
The same combiner box has to survive very different sites. The string count, mounting method and material all follow from the installation.
PV Combiner Boxes in the Field
Four installation contexts the EWJ-PV series is built for — from a plinth-mounted unit on a ground array to a wall-mounted box next to the inverter.
Customizing Your PV Combiner Box
Every enclosure in the EWJ-PV series is built to the project rather than pulled from a shelf. Six parameters are specified per order.
Certification and Testing
Test reports are available with the order. Certificates are issued per production batch, not per catalogue.
PV Combiner Box FAQ
The questions procurement and engineering teams raise most often.
What IP rating does a PV combiner box need?+
IP65 is the practical minimum for outdoor PV installations — it protects against dust and water jets. IP66 adds protection against powerful water jets and is worth specifying in coastal, open-rack or high-washdown sites. EWJ supplies both; the enclosure material and surface treatment should be matched to the environment.
How many solar strings can one combiner box take?+
Standard EWJ configurations run from 2 to 36 input strings. The most common commercial rooftop sizes are 4 to 16 strings, while utility-scale plants usually step up to 24 or 36. Non-standard string counts can be engineered against your module layout.
What does the 3.8kV voltage protection level mean?+
It is the maximum continuous voltage the internal surge protection device is rated for, so the box is suitable for PV systems operating at up to 1000V DC. The 20kA nominal discharge current indicates how much surge current the device can divert safely.
Can you add string monitoring to the combiner box?+
Yes. The internal layout is specified by you, so monitoring devices — per-string monitoring, current transformers or communication modules — can be positioned to match your monitoring architecture.
What is the difference between a PV combiner box and a junction box?+
A junction box simply terminates and protects individual panel conductors. A combiner box aggregates the DC output of multiple strings, and therefore carries the full array voltage and current — it is the boundary between the module field and the inverter, which is why surge protection and enclosure rating matter at this point.
Are these enclosures suitable for fire safety requirements?+
The metal housing provides a non-combustible enclosure with a controlled enclosure surface temperature, which is a key factor in fire safety assessment for PV installations. Specific project requirements should be reviewed against the installation layout before order.
PV Combiner Box for Your Next Solar Project
Send your string count, mounting preference, material and installation environment. We confirm the configuration, quote against your specification, and build against the approved sample.
Send Your Requirements
Tell us the string count, mounting method and site conditions. We reply within 24 hours with a matching configuration and a quotation against your specification.
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