What it is
The Molex 391001903 is the 3-circuit member of the Eurostyle 39100 series, a white enclosed-barrier terminal strip with a 0.315" (8.00 mm) pitch and dual-row layout. Screw-top termination accepts 12-22 AWG conductors into 6 wire-entry holes — three circuits front-accessed via the screw head, with the bottom side fully closed for dead-front protection. Rated 20 A per circuit at 300 V, the PA66 nylon housing carries a UL94 V-0 flammability rating and operates from -40°C through 105°C. The zinc-plated steel terminal screws are the mechanical load-bearing interface for field termination — torque to the spec in the product drawing to avoid cold creep on the wire.
What the key ratings mean
Current rating of 20 A per circuit at 300 V governs the wire-to-panel duty this strip handles — it is not a signal-only barrier block; the 12-22 AWG wire gauge range confirms it is sized for power distribution terminations within that current envelope. The 6 wire entries (6) mean each circuit has one input and one output — suitable for daisy-chain or feed-through wiring without a separate jumper. The enclosed barrier type is the dead-front rating — the housing shroud covers the live metal between adjacent circuits, which is the field-electrician safety baseline on chassis or panel-mounted power distribution. The top-screw / closed-bottom configuration means field termination is top-side only; confirm the enclosure depth above the mounting face allows screwdriver access before specifying. Operating temperature range of -40°C to 105°C and UL94 V-0 flammability rating together cover the typical industrial enclosure ambient — a closed panel in a motor-control cubicle often runs at the upper end of that window, so confirm your enclosure ventilation does not push local ambient above 105°C at the strip.
Sourcing
Listed Active with ROHS3 Compliant status — no official successor or cross-reference for this MPN. The part quotes to order against the BOM quantity; confirm your position count and the mating-panel cutout before committing.