The facts
- Locks at: the equipment inlet.
- Needs on the PDU side: nothing; the plug is a standard C14 / C20 / NEMA 5-15P / NEMA L6-20P.
- Needs on the equipment side: any standard inlet (C13 / C15 / C19 connector).
- How it holds: Spring fingers inside the connector grip the pins of any standard C14, C16 or C20 inlet as it is pushed on. The plug is a standard, non-locking plug, so the PDU side does not matter. The first universal locking connector; same current and voltage ratings as the plain connector. Available with IEC C14 / C20 plugs and NEMA 5-15P / L6-20P.
- How to release: Pinch the two red tabs on the connector head and pull.
- Published retention: no figure published by the maker.
- Plugs: C14, C20, NEMA 5-15P, NEMA L6-20P. Connectors: C13, C15, C19.
What it is
A-Lock is an equipment-side mechanism. Inside the connector, spring contacts grip the inlet pins themselves, so the hold comes from the standard IEC 60320 geometry every piece of rack equipment already has. There is no faceplate to clasp and no notch to find. Push it onto any C14, C16 or C20 inlet and it locks. The plug end is whatever the outlet needs, a NEMA 5-15P on a wall or power strip, a C14 or C20 on a PDU, and it does not lock; if the PDU end must hold as well, Dual-Lock is the pairing.
What it fits
Everything with a standard inlet, which is why it is the mechanism to choose when the PDU is unknown, mixed, or plain. Server, switch, storage shelf, UPS, KVM: if it has a C14 or C20 inlet, an A-Lock connector locks onto it.
Release
Squeeze the two red tabs on the connector and pull. The tabs are large and coloured on purpose: on a dark chassis in a dark rack you can find them by feel.
A-Lock or S-Lock?
Both lock onto any standard inlet. A-Lock releases by squeezing tabs; S-Lock releases by turning a collar. Where inlets sit in a tight row, some hands prefer the twist because it needs no side clearance; where gloves are worn, the tabs are easier. Either is right; pick the one your technicians already know.