Choosing a solar combiner box for your charge controller and balance-of-system (BOS) setup comes down to how many PV strings you need to consolidate and what protection you want between the panels and the inverter. The four boxes here span a two-string single-phase unit at the low end and a six-string three-phase enclosure at the high end, so the main task is picking the capacity and protection level that fit your array.
Quick take
Start by deciding how many panel strings you need to combine. If you only need two strings, the lowest-priced option is the 2-string PV combiner box with a lightning arrester connector. If you are planning a larger array, the six-string option in this group offers the highest capacity. The other two options sit in between with different input/output arrangements and protection packages.
Listed-price comparison
| Product | Listed price | Price bar |
|---|---|---|
| 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On | USD 74.99 | |
| 600V Solar DC Combiner Box with Lightning Arrester for On/Off Grid Systems | USD 103.99 | |
| 2 in 2 Out Solar Combiner Box,Pv Combiner Box with 20A PV Fuse,Dc 20A Circuit Br | USD 125.82 | |
| 6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker | USD 197.99 |
Decision matrix
| Your setup | Strong match | Why |
|---|---|---|
| Basic two-string single-phase array | 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On | Lowest listed price with lightning arrester protection |
| Single-phase on/off-grid array | 600V Solar DC Combiner Box with Lightning Arrester for On/Off Grid Systems | 600V 2-in/1-out design with fuses and arrester |
| Two-string array with extra surge protection | 2 in 2 Out Solar Combiner Box,Pv Combiner Box with 20A PV Fuse,Dc 20A Circuit Br | MCB, SPD, and fuse all included |
| Larger six-string three-phase installation | 6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker | Six-string capacity, three-phase, metal spray housing |
Product notes
600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On
At $74.99, this is the lowest listed price in the group. This 2-string combiner includes a 600V circuit breaker, a lightning arrester connector, four 15A DC fuses, and an IP65 waterproof ABS housing. It also includes a US country of origin and model number GX216R, which can help when you are comparing product versions. The configuration is Single Phase and the housing is plastic, so this is a straightforward match for a simple two-string single-phase setup. The main limitation is that it does not have the six-string capacity or the three-phase designation of the larger unit, so it is not suited to a bigger combiner job.
600V Solar DC Combiner Box with Lightning Arrester for On/Off Grid Systems
Listed at $103.99, this unit sits between the low-cost 2-string box and the 2-in/2-out model. It is a 600V 2-in/1-out unit with four 15A DC fuses, a high-voltage lightning arrester, and a circuit breaker. It is Single Phase with a Plastic housing, so it fits a compact single-phase on/off-grid setup. If you want a breaker and lightning arrester without going to a six-string box, this gives you that combination at a middle price. The trade-off is the 2-in/1-out layout, which is narrower than the 2-in/2-out unit and handles far fewer strings than the six-string model.
2 in 2 Out Solar Combiner Box,Pv Combiner Box with 20A PV Fuse,Dc 20A Circuit Br
At $125.82, this 2-in/2-out combiner packs a triple-protection setup: a 20A DC500V miniature circuit breaker, a DC500V 40KA Class T2 surge protective device, and a 20A DC500V fuse. It handles up to 20kW on a 500V system, with a maximum 20A per string and 20A output. The housing is ABS and polycarbonate, and the dimensions are 11.73 x 11.73 x 5.51 inches. That makes it a good fit if you want two inputs and two outputs with surge protection included. The trade-off is capacity: it is a 2-in/2-out unit, not a six-string box, and the 20A output breaker is part of the design, so match it to your expected output current.
6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker
At $197.99, this six-string unit carries the highest listed price in the group. It is also the only Three Phase unit in this group. It includes built-in 20A fuses, surge protection, a breaker, a metal spray housing with a lock and key, and an IP65 rating. It is suited to rural public facilities, residential off-grid systems, and factory grid-tied applications. If you need to consolidate six PV strings and want a more rugged enclosure with a lockable door, this is the product that matches that requirement. The trade-off is price: at nearly $198, it is a larger investment than the smaller single-phase and 2-in/2-out boxes, so it makes sense only if your array actually needs that many strings.
Final recommendation
- For a low-cost two-string single-phase setup, choose the 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On.
- For a compact single-phase on/off-grid box with a lightning arrester, choose the 600V Solar DC Combiner Box with Lightning Arrester for On/Off Grid Systems.
- For a two-string box with surge protection built in, choose the 2 in 2 Out Solar Combiner Box,Pv Combiner Box with 20A PV Fuse,Dc 20A Circuit Br.
- For a six-string three-phase enclosure with a metal spray housing, choose the 6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker.
