Product Overview

MC4 Y Branch Connector 4 to 1 is the highest-density parallel connector in the MC4 Y branch range, combining four PV strings into a single output cable. At this level of parallel combination, the connector is doing the work of a small combiner box. For large commercial and utility-adjacent systems where string groups of four are common, the 4 to 1 Y branch connector offers significant BOS simplification. It removes hardware from the array field, reduces potential failure points, and speeds up installation by eliminating the wiring labor associated with traditional combiner boxes.

Specifications

Parameter	Specification
Connector Type	MC4 Y branch, 4 to 1
Configuration	4 inputs → 1 output
Rated Voltage	1000V AC/1500V DC
Rated Current per Branch	30A
Total Output Current	120A (combined)
Contact Material	Copper alloy, tin plated
Housing Material	UV-resistant PPO, reinforced
Protection Rating	IP67
Temperature Range	-40°C-85°C
Wire Compatibility	2.5–6 mm² (input)/6–10 mm² (output)

Core Uses

Four-String Parallel Combination

The primary application. Four matched strings merge into a single high-current output that feeds directly to the inverter MPPT input or to a downstream combiner. The 4 to 1 connector handles the full combined current of four strings.

Field Combiner Box Replacement

In systems where four-string groups would traditionally require a field combiner box, the 4 to 1 Y branch eliminates that equipment entirely. This is particularly valuable in ground-mounted arrays where combiner boxes require posts, enclosures, and weather sealing.

Application Scenarios

Large Commercial and Industrial Arrays

Systems with 100+ panels commonly organize into four-string groups per MPPT channel. Replacing each group's combiner box with a 4 to 1 Y branch connector across the entire array can eliminate dozens of combiner boxes, saving thousands of dollars in equipment and labor on a single project.

Utility-Adjacent Ground-Mounted Systems

Ground-mounted projects in the 1–10 MW range use large numbers of string groups. The 4 to 1 Y branch connector reduces field equipment density, simplifies the array layout, and cuts the installation timeline by removing combiner box mounting and wiring from the critical path.

Selection Guide

Use the 4 to 1 Y branch when four matched strings need to combine and the total output current is within the connector rating. All four strings must be identical in configuration.

For fewer strings, use the 2 to 1 or 3 to 1 variant. For more than four strings, or when the design requires fuse protection at the combination point, a combiner box is necessary.

Y Branch vs Combiner Box: When to Use Each

	Y Branch Connector	Combiner Box
Parallel Strings	2–4	4–24
Fuse Protection	No	Yes
Monitoring	No	Optional
Enclosure	None needed	Required
Installation Time	Seconds	30–60 minutes
Maintenance	None	Periodic fuse and connection check
Best For	Small groups, simple systems	Large arrays, code-required fusing