What This 4-Position Buchanan Block Does on the Board
The 1546551-4 is a 4-position, single-level PCB terminal block from the Buchanan series, with a 3.50mm pitch. It terminates wires via a screw-actuated rising cage clamp — the screw lifts a nickel-plated copper cage that presses the wire against the current bar, rather than crushing the conductor directly. This gives a repeatable, gas-tight connection across the full 16-28 AWG range without nicking strands.
Rated for Control Circuits and Low-Power Distribution
Each position is rated 12 A at 300 V. For a 3.50mm pitch block, that current is on the higher side — the rising cage clamp and tin-plated copper alloy contacts handle the thermal load without the block softening. The 300 V rating covers most 120/240 VAC control circuits and DC power supplies inside equipment. If you're landing a 16 AWG feed for a small motor contactor or a 24 VDC sensor bus, this block has the headroom. The single-level design means all four terminations are on the same plane, so wiring is straightforward and the block stays narrow on the board.
Field Wiring and Termination Reality
The rising cage clamp accepts solid or stranded wire from 16 AWG down to 28 AWG. Strip length is standard for this class — about 6-7 mm — and the screw turns until the cage rises and grips. No special tool beyond a common screwdriver; the nickel-plated screw and clamp resist corrosion in humid panel environments. The green housing is a visual cue that this is a Buchanan-series block, which helps when you're tracing circuits in a dense terminal strip. Through-hole solder tails hold the block to the board; the 3.50mm pitch gives enough room between adjacent blocks for a screwdriver bit to fit without shorting.