What This Connector Is — and Where It Fits
The Molex 3-1123309-2 is a right-angle through-hole header from the Dynamic D-5200 series, a 4-position dual-row connector on a 10.16 mm pitch. It's a power interconnect — Board to Cable/Wire style — meaning it lives on the PCB and receives a mating cable-side receptacle. The 30 A per contact rating and 630 V voltage rating put it squarely in industrial power distribution, not signal-level duty. The wide 10.16 mm pitch gives the creepage distance needed for that 630 V without forcing an oversized board footprint, though the board layout engineer will note the 0.947" (24.06 mm) insulation height when planning component keep-outs.
What the Ratings Mean for the Fit
30 A per circuit means each power blade carries bus-level current — sized for the main DC rail or a motor feed, not a signal line. The 15.0 µin gold on the mating side handles the mating cycles you'd expect in a panel that gets serviced a few times a year; the tin on the solder tail is standard for wave-solder wetting. The board lock (two plastic pegs that snap into the PCB) holds the header in place during wave solder and takes the shear force from the cable harness — without them, the through-hole solder joints alone would carry that strain, and on a 10.16 mm pitch part the lever arm from a thick cable bundle can be significant.
Mounting and Mating Details
Through-hole, right-angle mounting — the pins come out the bottom of the board, and the connector body sits parallel to the PCB edge, so the cable exits along the board plane. The 4-wall shrouding protects the tabs and guides the mating receptacle; the detent lock gives an audible click when fully seated. IP20 means it's finger-safe on the panel side but not sealed — keep it inside an enclosure if there's washdown or condensation. The operating range is -55°C to 105°C, which covers most industrial cabinet environments.