The PV combiner box components keep the electrical circuit of the PV system safe. They collect direct current generated by multiple solar panels for centralized transmission. These components typically include DC SPD, DC fuses, DC disconnect switches (circuit breakers or isolator switch), wiring terminals, and monitoring devices in the combiner box. They ensure electrical circuit is safely and efficiently transmitted from the solar panels to the inverter or directly into the power grid.
This guide will introduce you to the components of a PV combiner box and its customization options.
PV Combiner Box Components
PV Combiner Box Components And Functions
The following are the main components of the photovoltaic combiner box.
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DC Circuit Breaker
When the current flow exceeds the safe level, be it due to a short circuit or too many devices connected, the circuit breaker trips and discontinues the flow. You can always reset the breaker once the issue is fixed.
DC Circuit Breaker Vs DC Isolator Switch
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Points Of Difference |
DC Circuit Breaker |
DC Isolator Switch |
|
Definition |
They are the electrical devices that break the current flow in case of any surge or overvoltage | It manually disconnects the specific circuit without interrupting the rest of the system. |
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Mode of operation |
Automatic |
Manual |
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Construction type |
It consists of an arc extinguisher, trip unit, and contacts. |
It’s a simple mechanical switch |
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Handling capacity |
Highest capacity |
No handling capacity |
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Usage |
Used for protecting the entire circuit |
Used for isolating the part of the circuit. |
|
Application |
Multiple applications: domestic and commercial as well as industrial application |
Mostly industrial application |
|
Cost |
Slightly expensive than the isolator switch |
Less-expensive |
*Table showing the differences between DC circuit breaker and DC isolator switch
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DC Fuse
The primary function of the DC fuse is to provide safety from short circuit or current overloads. It regulates the current flow through each string and disconnects power only to the affected string in the event of a fault. This design allows the other strings to operate smoothly and aids in troubleshooting.
DC Fuse
|
Points Of Difference |
DC Fuse |
DC Circuit Breaker |
|
Definition |
It melts so as to interrupt the overcurrent |
It trips to interrupt the overcurrent |
|
Number of use |
It can be used only once |
It can be used many times |
|
Response time |
Faster response to overvoltage, around 0.002 seconds |
Comparatively slower response, around 0.02 to 0.05 seconds |
|
Application |
Sensitive equipment |
General protection |
|
Cost |
Low cost |
Slightly higher cost |
|
Operation |
Automatic |
Both ways: automatic and manual |
*Table showing differences between a circuit breaker and a fuse
Types Of Fuses According To Voltage Handling Capacity
The type of fuse used for PV combiner boxes is the gPV fuse (General-purpose Photovolcanica Fuse). They are generally categorized based on their voltage ratings, which are:
- 1000V DC gPV fuse
- 1500V DC gPV fuse
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DC SPD
DC Surge protection devices in a PV system protect electrical equipment from overvoltage or short circuits resulting from direct or indirect lightning or due to operations switching. They also protect the solar panels and inverters from any overvoltage arising from any fault in the circuit.
They not only manage the voltage spikes but ultimately enhance the lifespan of equipment, preventing them from frequent repair or replacements.
DC Surge Protective Device
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Busbar
A busbar, a rectangular metal bar or strip, acts as a collective point for multiple incoming wires from numerous strings or arrays into a single component. It connects the incoming and the outgoing cables.
It is also used to combine the incoming negative and positive current wires from the solar panels separately. It facilitates handling complex and excessive wiring by combining and simplifying them at a single point.
Copper Busbar
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Enclosure
The enclosure is a crucial component of the solar combiner box as, most of the time, the combiner box is installed outdoors in harsh weather conditions and sun rays. They must be waterproof, corrosion-free, and U-V protected. They can be made of materials like high-grade plastic, fibreglass, or stainless steel.
waterpfroot plastic enclosure
Customization For PV Combiner Box Components
Each photovoltaic project is different from the other. The components and their types are added according to the specifications of the project.
customized solution for pv combiner box
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Enclosure Type
Our enclosures are rated under IP65. We offer enclosures for painted steel, stainless steel, glass-reinforced polyester (GRP), fibre-reinforced polyester (FRP), and polycarbonate enclosures.
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Number Of Strings
Our combiner boxes can be specifically customized to accommodate the number of strings as per the customer’s instruction diagram. The maximum number of strings in our combiner box amounts to 32 strings.
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Monitoring System
Often, the combiner box comes with an optional built-in wireless monitoring module. It not only monitors the performances of each active string but also tracks the system voltage, system temperature and the status of key components.
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System Voltage
Depending on the type of solar system and its nature of use, we offer voltage ratings from 600V DC to 1500V DC.
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SPD
The PV system is more at risk of surges due to direct lightning. That is why it is recommended that we install at least the type 2 SPD. Certain circumstances with relatively large professional setups may also demand installing type 1+2 SPD.
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Fuse Rating
The combiner box can handle variable input current ratings.
We offer combiner boxes with variable fuse ratings, such as 1-30A ratings in 10x38mm fuses and 25-32A ratings in 14×51 mm fuses with a voltage rating of 1000Vdc.
Another custom option is a 2.5 to 20A rating in 14x65mm with a 10mm extension and a 2.5A to 30A rating in a 10x85mm fuse with a voltage rating of 1500Vdc.
Why Choose LETOP For The Customized PV Combiner Box
LETOPf are the solar combiner box manufacturers per your specifications, we have a specialized team of experts and engineers, competent enough to arrange the photovoltaic combiner box components as per your professional and industrial needs.
Not only that, but we also provide professional guidance to decide the best solution after deeply analyzing your setup and application type.
LETOP is the right place for the best PV combiner box components and top-quality devices to take your business to the next level. Our wide range of electrical devices, switches, and solar PV combiner boxes are versatile and up-to-date, providing the modern-day solution to your commercial and industrial needs.
Let’s join hands and take your photovoltaic project to the next level!
Combiner Box for Photovoltaic Projects
Frequently Asked Questions
What Is In A PV Combiner Box?
A PV combiner box consists of some DC string fuses and fuse holders, circuit breakers, surge protection devices, busbars, and the necessary wiring and enclosures. Some Combiner boxes come with optional built-in monitoring devices.
How Does A Solar Panel Combiner Box Work?
A solar panel combiner box is a device that combines the multiple strings from the solar panel into one single circuit. It integrates and organizes the wires and provides circuit and surge protection.
Can You Customize The Number Of Input Strings In A PV Combiner Box?
Yes, a PV combiner box can accommodate a customized number of strings. They are designed for string input from 1 string to 32 strings.
When Is It Recommended To Use A PV Combiner Box?
It is recommended to use a PV combiner box if more than 2 strings from the solar panel need to be combined into a single unit.
Final Thoughts
A PV combiner box is an integral device for a PV system’s safe and organized working. Understanding the PV combiner box components, along with their assigned functions and options for customization, will help you decide on the most reliable manufacturer so that your photovoltaic system may function effectively and safely for an extended period. Here is a video from YouTube to learn more “What is a PV combiner box?”.
What is a PV combiner box?
