Photovoltaic Combiner Box

Shangming is a high-quality photovoltaic combiner box manufacturer from China. We have our own factory with over 5 production lines, and standard-specification products are readily available for purchase with fast delivery. Customization is also our strength; please contact us to discuss solutions and obtain a free quote.

Why Are Photovoltaic Combiner Boxes Needed?

In a medium to large-scale photovoltaic power plant, there are typically hundreds or even thousands of solar panels. If each panel were directly wired to the inverter, it would cause many problems. First, the wiring would be messy, greatly increasing construction difficulty, and the consumption of a large amount of DC cable would significantly increase costs.

Simultaneously, losses would increase, and transmitting small currents over long distances would result in significant voltage drops. Later, maintenance would also become a challenging problem, as it would be difficult to quickly locate faulty strings.

This is where combiner boxes come in, solving these problems. They act like a transportation hub, converging the small streams into a unified output.

Module Composition

Core Functions

Current Collection: The photovoltaic combiner box centrally outputs the DC current from multiple photovoltaic modules, reducing the number of DC cables and lowering system complexity and cost.

System Protection: The combiner box provides overcurrent, short-circuit, reverse connection, and surge protection for each string and the total output, preventing fault escalation.

Safety Isolation: A DC disconnect switch enables rapid disconnection during maintenance or faults, improving operational safety.

Operation Monitoring: If an intelligent model is selected, real-time monitoring of string current, voltage, temperature, and lightning protection status is possible, facilitating fault location and performance analysis.

Main Types

Different types of photovoltaic (PV) combiner boxes vary in installation location, voltage level, and level of intelligence within a system, corresponding to different application scenarios.

1. DC Combiner Box

Most common in PV power plants, installed between PV modules and the DC inverter.

Function: Combines the DC power from multiple PV strings and outputs it to a centralized inverter.

Core Configuration: Includes DC fuses, DC circuit breakers, and SPDs.

Applicable Scenarios: Large-scale ground-mounted power plants, centralized PV systems.

2. AC Combiner Box

Primarily used in systems employing string inverters. It is installed between the AC output side of the inverter and the step-up transformer.

Function: Combines the AC power output from multiple string inverters.

Core Configuration: AC circuit breakers, AC surge protectors, disconnect switches; some may also include an energy meter.

Applicable Scenarios: Commercial and industrial rooftop PV, ground-mounted power plants using distributed inverters.

3. Intelligent Combiner Box

This type of box adds a monitoring module to the basic combiner box and is currently the mainstream choice for medium to large-sized power plants.

Functions: In addition to combining current, it can monitor the current of each incoming line, total voltage, internal temperature, and surge protector status in real time.

Technical Advantages: Through data upload, maintenance personnel can remotely determine which solar panels are shaded or damaged, enabling precise maintenance.

Warranty and After-Sales Service

Shangming Factory provides quality assurance, specifically a 1-year warranty for customized products and a 2-year warranty for standard products. The warranty covers cabinet material defects, component malfunctions (under normal use), and manufacturing process issues. Damage caused by improper installation, misuse, natural disasters, or unauthorized modifications is not covered.

In case of after-sales issues, we will handle them according to the following process: Report the problem (provide photos/videos of the malfunction and order number) → Technical team responds within 4 hours → Remote diagnosis (free guidance on adjusting parameters or replacing small components; free replacement parts within the warranty period) → If the problem cannot be resolved, an engineer will be arranged for on-site handling or the product will be returned for repair/replacement (costs within the warranty period will be borne by us); in emergencies, replacement products can be provided first to minimize customer losses.