When you're wiring a solar array, the combiner box is the junction where panel strings come together into one output. The problem is choosing how many strings you need and how much protection you want without overspending. Here we pit two combiner boxes against each other: a 6-string model with built-in 20A fuses and a lockable metal housing, and a 4-string model with a 63A breaker and surge protection. One is priced well above the other, so the decision comes down to array size and budget.
Quick Verdict
If your solar array has more than four strings, or you want per-string fusing and a lockable metal enclosure, the 6-string box is the more complete package. If you're working with a typical four-string setup and want to keep costs down, the 4-string box delivers the essential breaker and protection for far less money. In short: 6 strings for larger arrays and integrated fuses, 4 strings for cost-conscious smaller systems.
At a Glance
| Feature | 6-String Combiner Box | 4-String Combiner Box |
| Price | $197.99 | $62.54 |
| Input Strings | 6 | 4 |
| Protection | 63A breaker, surge protection, 20A per-string fuses | 63A breaker, surge protection |
| Housing | Metal with lock and key | ABS/PC |
| Weather Rating | IP65 | IP65 |
Where Each Product Wins
The 6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker is the pick when you have six separate panel strings to combine, want individual 20A fuses on each string, or prefer a metal housing with a lock for outdoor or security-minded installations. Both boxes include a circuit breaker and surge protection, so the differentiators here are the per-string fusing and the pre-wired metal enclosure.
The 4 String Solar Combiner Box PV Combiner Circuit Breaker 63A wins on price and ease of wall mounting. It also provides a circuit breaker and surge protection, but its compact ABS/PC body and lower price make it a practical choice for a four-string solar panel system.
Product Notes
6 String Solar Combiner Box with 20A Fuse, Surge Protection & 63A Breaker
This box is built for larger arrays. It combines six panel strings into one output and packs in 20A rated fuses plus a 63A breaker, all in a pre-wired metal housing with a lock and key. The IP65 rating means it can handle rain and moisture. The biggest reason to choose it is the per-string fusing and the lockable metal enclosure, so you don't need to add external fuse holders. The limitation is its higher price, which sits well above the 4-string alternative. That higher cost makes sense only if your array genuinely needs six strings or you value the integrated fuses and sturdy housing.
4 String Solar Combiner Box PV Combiner Circuit Breaker 63A
This is the less expensive option for a four-string solar array. It comes with a 63A circuit breaker and mounts to the wall using the included mounting plates. The reason to pick it is the price: it comes in substantially lower than the 6-string box, so you get core electrical protection without the high outlay. The limitation is the 10A maximum input current per PV string and the four-string capacity. If your panels output more than 10A per string or you need to combine more than four strings, this box will be undersized. For a typical small array, however, it's a solid match.
Final Choice by Use Case
Choose the 6-String Solar Combiner Box if you have six strings to merge, need per-string 20A fuses, or want a lockable metal housing for outdoor or high-security installations. Its $197.99 price buys all-in-one protection that would otherwise require many separate components.
Choose the 4-String Solar Combiner Box if you're keeping costs down, your array fits within four strings, and your panel current stays under 10A per string. At $62.54, it's the lower-cost pick for smaller solar systems.
