When you're choosing a solar combiner box for a charge controller and balance-of-system (BOS) setup, the decision usually comes down to one thing: how many panel strings need to meet safely before the power moves on. Two combiner boxes in this range approach that job from opposite ends: the 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On is built around a two-string layout, while the 4String Solar PV Combiner Box 63A Circuit Breaker Solar Panel System Waterproof accepts four strings and sends them out as one.
Quick verdict
Pick the 2-string box when a lightning arrester and four 15A DC fuses are the protection path you want for a two-string array. Pick the 4-string box when you need four strings to meet in one box with two surge protection devices.
At a glance
| Consideration | 600V 2-String Combiner | 4-String 63A Combiner |
|---|---|---|
| Listed price | USD 74.99 | USD 61.91 |
| Price bar | ||
| String inputs | 2-string configuration | 4 inputs, 1 output |
| Surge protection | High-voltage lightning arrester | 2 surge protection devices, 40KA/600V |
| Max output voltage | 600V | 600V |
| Circuit breaker | 63A | 63A |
| Enclosure | IP65 waterproof ABS housing | IP65 ABS/PC, wall mount |
Where each product wins
- 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On wins when you want one high-voltage lightning arrester plus four 15A DC fuses working together before the DC feed leaves the combiner.
- 4String Solar PV Combiner Box 63A Circuit Breaker Solar Panel System Waterproof wins when you need four string inputs, two surge protection devices, and a 40A total input current in a wall-mount housing.
Product notes
#### 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On
With a 9 x 5.1 x 9-inch footprint and a 3.19-pound weight, this box is configured around a 600V two-string layout. Its protection setup includes one high-voltage lightning arrester and four 15A DC fuses, so overvoltage and overcurrent events are handled in one enclosure. The case is rated IP65, which supports outdoor balance-of-system use. Choose it when your array can be combined into two strings and you want the lightning arrester and fuses to share protection duties. The limitation is the number of inputs: if you have four separate strings, you would need to combine circuits before this box or move to a larger four-string combiner.
#### 4String Solar PV Combiner Box 63A Circuit Breaker Solar Panel System Waterproof
This 4-string combiner accepts four PV array inputs and combines them into one output string. Its input limits are 10A per single PV array and 40A total, with a maximum input voltage of 1000V per array and a maximum output voltage of 600V. Two surge protection devices rated 40KA/600V and one 63A breaker sit inside the IP65 ABS/PC housing, which is intended for wall mounting. The package also includes a combination lock and mounting plates. Choose it when you need four strings to meet in one box and want dual surge protection with a 40A total input path. The limiting detail is the 10A per-array input current, so higher-current arrays should be split into more strings before reaching this box.
Final choice by use case
- Choose the 600V Solar DC PV Combiner Box,2 String with Lightning Arrester Connector for On for a two-string array where a lightning arrester and fused overcurrent protection are the priorities.
- Choose the 4String Solar PV Combiner Box 63A Circuit Breaker Solar Panel System Waterproof for a four-string array that needs dual surge protection, a 40A total input path, and a wall-mount housing.
