The 284518-4 is a 4-position, single-level, shrouded male pin header from the TE Buchanan series. It's the board-side half of a 3.81mm-pitch terminal block interface — mates with the corresponding Buchanan plug that carries the field wiring. Vertical through-hole orientation with 0.134" (3.40mm) solder tails — the pins sit perpendicular to the board, which simplifies routing when the mating plug enters from above. The two-side shroud guides the plug and protects the pins during blind mating in a panel or junction box.
3.81mm pitch is the centre-to-centre spacing between adjacent pins. That's the dimension you need for the PCB layout — the footprint is 4 holes on a 3.81mm grid, with the solder tails spaced accordingly. It also sets the minimum creepage distance between circuits at the board surface. 11 A per contact at 300 V is the UL-rated maximum. In practice, derate if the ambient temperature exceeds the 110°C upper limit of the operating range, or if multiple adjacent circuits are fully loaded — the housing material's thermal conductivity limits the total heat dissipation.
Mounting and termination details for the board builder
Through-hole solder termination: the 0.134" (3.40mm) tail length is designed for standard 1.6mm PCBs — the tail protrudes enough for a reliable solder fillet on the bottom side without being so long that it interferes with components on the opposite face. The header is inserted from the top and wave-soldered or hand-soldered. That's the z-height budget you need above the PCB — the mating plug adds its own height on top of that. The green PA66 housing is keyed by the shroud geometry; there's no polarisation key on the side, so orientation is set by the PCB footprint. Interlocking (Side) feature means multiple headers can be ganged side-by-side to create a wider multi-position assembly — useful when you need more than 4 circuits in the same pitch but want to keep the PCB layout modular.
Lifecycle and sourcing — active production, no cross-reference
ROHS3 compliant, which covers the current EU RoHS exemption list. No official pin-compatible replacement or cross-reference exists within the Buchanan series — this is the part number for the 4-position vertical shrouded header at 3.81mm pitch.