What the standard defines
There is no MC4 standard. MC4 is the designation of a connector originally made by one manufacturer, whose shape became so widespread that the name now describes a family of look-alike connectors from dozens of makers. What the name conveys is a form factor: a snap-together pair with a locking latch, a sealed body, and a crimped contact sized for the common solar cable cross-sections.
What is published are the connector standards those products are tested against, which cover rated voltage and current, contact resistance, temperature cycling and ingress protection. A maker that cites one is saying its connector was assessed; a maker that only says “MC4 compatible” is describing a shape.
What it does not promise
The name does not promise that two connectors from different makers form a safe pair. Contact pressure, seal geometry and plating differ, and the makers themselves discourage mixing — a mixed pair mates, passes current, and is the one found warm on a thermal check.
Nor does it promise a current rating: that belongs to the specific product and the cable crimped into it. A connector rated 30 A on 6 mm² cable is not rated the same on 2.5 mm².
What it works with
MC4-style connectors terminate almost every panel on this site and most extension cables, and they are the interface between a panel and a charge controller or a station. The crimping tool, the cable cross-section and the spanner that tightens the gland are all part of making one properly, which is why those sit on their own shelves here.
What people ask before they order
Can I mate an MC4 connector from one brand with another?
Mechanically, usually. But the makers state that intermateability is not guaranteed across brands, because the contact pressure and the seal are designed as a pair. This site reports what each maker says rather than treating the name as a guarantee.
Is MC4 an IEC standard?
No. Connectors of this type are tested against connector standards such as IEC 62852, but the name MC4 is a product designation, not a published standard. That distinction is the whole point of this page.
Last reviewed 16 September 2026