Receptacle orders go wrong at the NEMA line item: the equipment arrives needing a 6-20R and the wall has a 5-20R. The selector table below reads straight off the plug pattern, covers the 240V families, and keeps the spec honest before anything ships.
Receptacle NEMA Configurations at a Glance
| NEMA | Rating | Identifying Pattern | Typical Use |
| 5-15R | 15A, 125V | Two vertical blades plus ground | The standard duplex receptacle for general use |
| 5-20R | 20A, 125V | T-slot neutral | Kitchen, equipment, and 20A commercial circuits |
| 6-15R | 15A, 250V | Two horizontal blades | Small 240V equipment |
| 6-20R | 20A, 250V | One horizontal, one vertical blade | Window air conditioners, commercial equipment |
| 6-30R | 30A, 250V | Larger body, dedicated circuit | Compressors and larger fixed equipment |
| 14-30R | 30A, 125/250V | Four-wire with neutral | Electric dryers |
| 14-50R | 50A, 125/250V | Four-wire with neutral | Ranges, RV pedestals, EV charging circuits |
| L5-20R | 20A, 125V | Curved locking blades | Equipment that cannot risk unplugging |
| L6-30R | 30A, 250V | Curved locking blades | Stage, shop, and industrial equipment |
Read the code like a part number: the first number family sets voltage class, the second sets amperage, R means receptacle and P means plug. Match the receptacle to the equipment plug on the schedule and confirm the branch circuit rating with the electrician of record before the order ships.
240V Outlet Basics
The 6-series straight-blade patterns carry no neutral, so they serve straight 240V loads like compressors and window air conditioning. The 14-series adds a neutral for split 120/240V appliances, which is why ranges and dryers land on 14-50R and 14-30R. EV charging commonly reuses the 14-50R pattern on a dedicated circuit; confirm the charger manufacturer's receptacle and circuit requirements plus local code before speccing it. Locking L-series patterns twist to lock so vibration and cord tension cannot disconnect the equipment, which is why they own stage, shop, and temporary power work.
Commercial and Hospital Grade in Brief
Commercial and spec grade receptacles carry heavier contact material and higher cycle ratings than residential devices, and hospital grade adds the UL 498 green dot tests for ground pin retention required in patient care areas per NEC 517. The full grade education, including where residential grade is defensible, lives on the parent outlets page; this page keeps its depth on configuration.
Ordering Notes for Spec Projects
Five checks before a bulk electrical outlet order goes out. Confirm each NEMA configuration against the equipment schedule, not against memory. Verify tamper-resistant requirements for the occupancy per NEC 406.12. Hold electrical outlets to one color and finish per room schedule, with matching wall plates. Check box fill and gang counts against the device layout via boxes and fittings. And map GFCI locations per NEC 210.8 with the chart on our GFCI outlets page. Send the finished schedule and we will quote the receptacle package at contractor pricing, hospital grade and locking patterns included.