PV Connector Selection Guide: Five Decisions That Narrow the Catalog
Selection rarely starts with a part number. Five inputs remove most candidates before anyone opens a datasheet: system voltage, string current, the function the connector has to perform, cable cross-section, and the documentation the project requires. Each section below points to the page where that trade-off is argued in detail.
1. System voltage: 1500 V or 1000 V
Voltage class sets insulation coordination and creepage distance before anything else. Moving to 1500 V cuts string count and current, but it narrows the field of listed components and changes derating practice.
2. String current and module type
Rated current is a temperature problem, not a figure printed on the housing. Bifacial modules and short strings change the duty cycle; the derating curve decides whether the peak value holds.
3. What the connector has to do
Most joints are feed-through connections. Where protection or bypass current enters the design, the device type changes before any other parameter.
Fuse connector selection: 10.3x85 vs 10.3x38
When a string actually needs a fuse, and which body size fits the fault current.
Diode connector selection: D4A vs D4B
Bypass current ratings, enclosure differences and IP class.
Solar fuse connectors
Production families with documented ratings.
PV diode connectors
Bypass diode connectors used at module and string level.
4. Cable cross-section and run length
Cross-section follows from current and allowable voltage drop, and it fixes the crimp range and cable gland the connector has to accept. Choose the cable first.
PV DC cable sizing: 4, 6 and 10 mm2
Quick selection by size, followed by the voltage-drop check.
Why H1Z2Z2-K became the panel cable standard
Construction, temperature rating and what EN 50618 covers.
Extension cable sizing and voltage drop
Conductor, XLPO insulation and how to size long runs.
Solar PV cable
Specifications by cross-section and conductor class.
5. Compliance and documentation
Two products carrying identical ratings can still fail on different obligations: what a certificate covers, who documents intermateability, and which listing the inspector asks for.
PV connector and cable standards
IEC 62852, EN 62852, UL 6703, EN 50618: scope and limits of each.
TÜV vs UL certification
What each mark verifies, and why neither replaces the other.
Cross-mating between brands
Why mixed junctions fail, and the documentation route that is defensible.
NEC 2026 690.33(C)
Intermateability has to be documented by both manufacturers.
Where to start, by situation
| If you are specifying | Start with | Check before ordering |
|---|---|---|
| A string joint made on the cable, 1500 V or 1000 V | CN4U-C solar cable connector | Rated to 70 A; match the crimp range to the conductor diameter |
| Termination on a module or junction box | CN4U-P solar panel connector | Rated to 52 A |
| Parallel strings above the reverse-current limit | Solar fuse connector | Body size 10.3x85 vs 10.3x38, fuse current 1 to 30 A |
| Shading that calls for bypass current | PV diode connector | D4A vs D4B: current rating and enclosure |
| Long runs or non-standard lengths | Solar PV cable and extension assemblies | Size for voltage drop before choosing glands |
| Mixed brands or successive module generations | Cross-mating documentation | NEC 690.33(C): documented by both manufacturers |
The figures quoted here are the published ratings of the families shown. Test methods, permissible values and the limits of each certificate are set out in the pages linked above.
Still choosing between two options?
Send the system voltage, string current and cable size; the selection notes come back with the specific part numbers.