The NEMA 5-15R is the receptacle counterpart to the 5-15P plug — the grounded outlet that accepts nearly every general-purpose plug in North America. The familiar duplex wall outlet with two vertical slots and a rounded ground hole is a pair of 5-15R receptacles. It is rated 15 amperes at 125 volts.
Contact Layout
A 5-15R presents three contacts that mirror the plug: a shorter slot for the hot blade, a taller slot for the wider neutral blade, and a rounded socket for the grounding pin. The differing slot widths enforce polarization — a polarized plug can only be inserted one way, keeping the device's switched and fused paths on the intended conductor.
Panel, Cord-End and In-Line Variants
While most people meet the 5-15R as a wall outlet, the same configuration appears in several forms:
- Wall/duplex — the standard installed receptacle in a device box
- Cord-end (connector body) — molded or assembled onto the end of a cord to make an extension cord or power strip inlet
- Panel-mount — flanged receptacles built into equipment enclosures and power distribution units
A cord-end 5-15R is what turns a length of flexible cord into an extension cord, and it relies on a good strain relief to survive repeated flexing and unplugging.
Ratings, Tamper Resistance and Standards
Modern installed 5-15R receptacles are frequently tamper-resistant (TR), using internal shutters that open only when both blades are inserted simultaneously — a requirement in many dwelling locations under the National Electrical Code. Dimensional and performance requirements are set by NEMA (WD-6) and safety-listed under UL 498. When a receptacle will see continuous load, designers often step up to a 20-ampere 5-20R, whose T-shaped neutral slot accepts both 15A and 20A plugs.
Grades and Wiring
Receptacles are built to different duty grades — residential, commercial (spec) and hospital — that differ in contact retention and mechanical endurance rather than in the 5-15R pattern itself. They can be connected by side screw terminals, by a clamped back-wire terminal, or by push-in “backstab” holes; screw or clamp terminations are generally preferred for a durable, low-resistance connection. Whichever grade is used, the configuration a cord sees remains the same familiar three-contact 5-15R.