Power Cord Types Explained: NEMA 5-15P, IEC C13, C14, C19 and Wire Gauge

Power cords are the least glamorous cable you'll buy and the one most likely to be ordered wrong. The codes on the listing — NEMA 5-15P, IEC C13, 18AWG, SJT — describe exactly what fits and how much current it safely carries. Here's how to read them.

The two naming systems

NEMA names North American wall plugs and receptacles. The one you know is NEMA 5-15P — the standard three-prong US plug, rated 15A at 125V (its receptacle twin is the 5-15R).

IEC 60320 names the connectors on the equipment end, and they come in male/female pairs one digit apart:

• C13/C14 — the workhorse pair on desktops, monitors, printers, PSUs and rack gear, rated to 10A (15A in North American practice for the cordset). The C13 plugs into your device; the C14 is the inlet shape.
• C19/C20 — the bigger rectangular pair for high-draw equipment: servers, UPS units, PDUs, rated to 20A.

Wire gauge: the number that actually matters

AWG runs backwards — a lower number means thicker copper and more safe current:

• 18AWG — up to 10A. Monitors, desktops, most office equipment.
• 16AWG — up to 13A. Workstations, larger PSUs, gear that runs hot.
• 14AWG — up to 15A. Servers, high-wattage power supplies, C19 equipment, anything you'd rather over-spec than under-spec.

The jacket code you'll see on our listings, SJT, is a hard-service thermoplastic jacket rated for 300V — standard for equipment cords. UL and cUL listing marks mean the cordset design has been safety-tested, not just the wire.

The three cords that cover almost everything

• Wall to equipment: NEMA 5-15P to C13 — the classic computer/monitor cord. Pick the gauge for the load: North American power cords in 18, 16 and 14AWG.
• PDU or UPS to equipment: C14 to C13 jumper cords — both ends IEC, so they work worldwide at 100–250V. Colored jackets (blue, green, red) make A/B power feeds traceable in a dense rack.
• Extending a reach or splitting an outlet: 5-15P to 5-15R extension and splitter cords in heavy 16AWG.

Three mistakes to avoid

• Undersized gauge on a big load. An 18AWG cord on a 900W server PSU runs hot. When in doubt, step down a gauge number.
• Daisy-chaining extension cords. Use one cord of the right length — we stock lengths up to 25 ft — not three short ones in series.
• Guessing C13 vs C19. If the inlet on your equipment is the wide rectangular type, it's a C20 inlet and needs a C19 cord; the smaller trapezoid takes C13. A photo of the inlet is all we need to confirm — send it over.

Browse all power cords, extensions and splitters, and C14-to-C13 jumpers — every listing states plug pair, gauge, amperage, jacket and length so you can match the spec, not the picture.