EXCB3-DC4-2 – 4 In 2 Out DC Combiner Box with Isolator

EXCB3-DC4-2 – A Versatile 4 In 2 Out DC Combiner Box with Integrated Safety Features

The EXCB3-DC4-2 4 in 2 out DC combiner box from HUYU Electric is specifically tailored for dual MPPT systems in photovoltaic installations. Designed with safety in mind, this product consolidates four DC input strings into two independent outputs. Each output is protected by a manual DC isolator switch, which features a lockable mechanism and a visible disconnect to ensure absolute safety during maintenance work. Additionally, the box integrates a dependable Type 2 surge protective device (40kA Imax), safeguarding both outputs against lightning-induced surges.

Encased in a robust IP65 and IK10 rated PC/ABS enclosure, this combiner box is optimized for outdoor applications and supports wall-mounted installation. The factory pre-wired design simplifies installation, minimizing wiring errors and saving time. Certified by CE, TUV, and CB, it complies with rigorous global safety standards. HUYU Electric also offers customized OEM/ODM solutions with private labeling and full documentation, making this an ideal choice for solar distributers seeking a reliable, safety-compliant product.

Technical Specifications – EXCB3-DC4-2

This DC combiner box is especially designed for dual MPPT systems, with manual, lockable switches that ensure there is no power flow during maintenance. The durable PC/ABS enclosure, rated for IP65 and IK10 certification, makes it suitable for outdoor installations, providing long-lasting protection even in harsh environments.

Enhancing Solar Safety Through Manual DC Isolation

As solar installation safety becomes increasingly regulated, jurisdictions often require an added layer of safety by mandating a “visible break” feature on the DC side. The EXCB3-DC4-2 DC combiner box directly meets these requirements by offering reliable manual DC isolator switches, one for each output. This ensures technicians can eliminate energy flow when maintaining inverters or panels, providing unmatched safety compared to traditional circuit breakers which can be reset accidentally.

OEM/ODM Supply – Safety-First Isolator Combiner Boxes for PV Projects

Buyer’s Guide

Key Considerations for Choosing an Isolator-Type Combiner Box

Navigate the selection process for isolator-based combiner boxes, focusing on safety and efficiency.

1. Prioritize Safety with Isolator Switches

The EXCB3-DC4-2 offers unparalleled safety with its lockable, visible DC isolators. These switches ensure absolute disconnection of power during maintenance, offering a superior choice over simple circuit breakers, which can be unintentionally re-engaged.

2. Optimization for Dual MPPT Systems

Tailored for dual MPPT inverters, this combiner box allows pairing of four strings into two independent outputs, ensuring the system maximizes power generation even under varying conditions such as partial shading or different panel orientations.

3. Add Overcurrent Protection

The optional 15A–32A DC fuses provide essential overcurrent protection for each PV string. This layered safety design ensures that the isolators facilitate maintenance, while the fuses safeguard against overcurrent conditions.

4. Robust Enclosure for Outdoor Reliability

The IP65 and IK10-rated PC/ABS enclosure resists environmental and physical damages, ensuring the safety and reliability of the connected systems. Designed for vertical wall mounting, the pre-stamped cable glands simplify on-site installation.

Frequently Asked Questions

Is a solar combiner box necessary for a 4-string PV system?

Yes, a solar combiner box is essential for a 4-string PV system. It provides a centralized point for protection and disconnection that is required by electrical codes. The EXCB3-DC4-2 4 in 2 out DC combiner box is especially important as it not only combines and protects the strings but also provides the manual, visible isolation switches that modern safety regulations often mandate for rooftop and building-attached solar systems.

Does a solar combiner box increase the voltage?

No, a solar combiner box does not increase the voltage. It connects multiple string inputs in parallel. In a parallel connection, the voltage remains the same as a single string, while the total current is the sum of the currents from each string. For instance, if you have two strings each with a voltage of 400V and a current of 10A, the combined output will be 400V at 20A. Voltage is only increased by connecting components in series.

What does a combiner box do for solar panels?

A combiner box for solar panels serves three critical roles. First, it merges the DC output from multiple strings into a smaller number of outputs. Second, it provides a safety barrier, with surge protection to shield the inverter and overcurrent protection (fuses) for each string. Third, it offers a manual disconnect point. The EXCB3-DC4-2 DC combiner box with isolator excels in this third role by using lockable manual switches that provide a visible break in the circuit, ensuring the highest level of safety for anyone working on the system.

What is the difference between a 4-in-1-out and a 4-in-2-out combiner box?

The main difference is the output configuration and its intended inverter type. A 4-in-1-out DC combiner box merges all four strings into a single output, designed for a single-MPPT inverter. A 4-in-2-out combiner like the EXCB3-DC4-2 splits the four inputs into two independent output groups. This is specifically for dual MPPT inverters, allowing each group of strings to operate and be optimized independently, which maximizes energy harvest, especially on roofs with multiple orientations. It also allows you to isolate and lock off half the array while the other half continues to operate.