Plug and Receptacle Configurations: The Identification Chart
Read the face, get the rating. A NEMA designation fixes one voltage, one ampere rating and one pole and wire count. This chart confirms what a designation means and shows the receptacle face that goes with it.
- Answers
- Which plug or receptacle is this, and what is it rated for?
- Format
- Spec chart
- Sources
- 20 cited
- Last checked
How to read a designation
| Part | Example | Meaning |
|---|---|---|
| Letter L in front | L14-30R | Locking type. NEMA: locking configurations are identified by the letter L preceding the designation, L5-15 versus 5-15.1 |
| Number before the hyphen | L14-30R | The series: one fixed combination of voltage, poles, wires and grounding. Eaton calls it the NEMA prefix. Series 14 is 125/250 V, 3 pole, 4 wire, grounding.8 5 |
| Number after the hyphen | L14-30R | Amperes. NEMA decodes an L22-20R as a locking type, 277/480 volt, 20 ampere, 3-phase wye, 4 pole, 5 wire grounding receptacle.1 |
| Letter at the end | L14-30R | R is the receptacle, the face with slots. P is the plug, the face with blades. In the charts the open-slot drawing carries the R label and the solid-blade drawing the P label.2 5 |
| Letters on the face | G, W, X, Y, Z | G is the equipment ground. W is the grounded conductor, the neutral. X, Y and Z are the line terminals.1 |
Straight blade receptacles
| Series | Voltage | Poles, wires | Grounding | Designations | Notes |
|---|---|---|---|---|---|
| 1 | 125 V | 2 pole, 2 wire | Non-grounding | 1-15 | |
| 2 | 250 V | 2 pole, 2 wire | Non-grounding | 2-15, 2-20, 2-30 | The Bryant chart shows 2-15 as a plug only.4 |
| 5 | 125 V | 2 pole, 3 wire | Grounding | 5-15, 5-20, 5-30, 5-50 | Eaton lists its 5-30 and 5-50 devices for welding equipment.7 |
| 6 | 250 V | 2 pole, 3 wire | Grounding | 6-15, 6-20, 6-30, 6-50 | Eaton lists its 6-30 and 6-50 devices for welding equipment.7 |
| 7 | 277 V AC | 2 pole, 3 wire | Grounding | 7-15, 7-20, 7-30, 7-50 | Bryant states it does not make a 7-20. Eaton lists a 7-20 plug.11 5 |
| 10 | 125/250 V | 3 pole, 3 wire | Non-grounding | 10-20, 10-30, 10-50 | No ground terminal. Eaton lists 10-30 and 10-50 for replacement use in older homes with 3-wire range and dryer connection points.7 |
| 11 | 3-phase 250 V | 3 pole, 3 wire | Non-grounding | 11-15, 11-20, 11-30, 11-50 | |
| 14 | 125/250 V | 3 pole, 4 wire | Grounding | 14-15, 14-20, 14-30, 14-50, 14-60 | Eaton lists 14-30 and 14-50 for homes with 4-wire range and dryer connection points. Legrand lists a 14-50R for RVs and travel trailers.7 14 |
| 15 | 3-phase 250 V | 3 pole, 4 wire | Grounding | 15-15, 15-20, 15-30, 15-50, 15-60 | |
| 18 | 3-phase wye 120/208 V | 4 pole, 4 wire | Non-grounding | 18-15, 18-20, 18-30, 18-50, 18-60 | |
| TT | 125 V | 2 pole, 3 wire | Grounding | TT-30 | Travel trailers and RVs. Not in the Hubbell, Bryant or Eaton rating charts; four manufacturers’ product documents agree on the rating.7 12 14 20 |
Locking receptacles
| Series | Voltage | Poles, wires | Grounding | Designations | Notes |
|---|---|---|---|---|---|
| L1 | 125 V | 2 pole, 2 wire | Non-grounding | L1-15 | |
| L2 | 250 V | 2 pole, 2 wire | Non-grounding | L2-20 | |
| L5 | 125 V | 2 pole, 3 wire | Grounding | L5-15, L5-20, L5-30 | Hubbell sells an L5-30P as a marine shore power hull inlet.15 |
| L6 | 250 V | 2 pole, 3 wire | Grounding | L6-15, L6-20, L6-30 | |
| L7 | 277 V AC | 2 pole, 3 wire | Grounding | L7-15, L7-20, L7-30 | |
| L8 | 480 V AC | 2 pole, 3 wire | Grounding | L8-20, L8-30 | |
| L9 | 600 V AC | 2 pole, 3 wire | Grounding | L9-20, L9-30 | |
| L10 | 125/250 V | 3 pole, 3 wire | Non-grounding | L10-20, L10-30 | |
| L11 | 3-phase 250 V | 3 pole, 3 wire | Non-grounding | L11-15, L11-20, L11-30 | L11-15 appears only in the Bryant chart and Eaton’s rating table.4 6 |
| L14 | 125/250 V | 3 pole, 4 wire | Grounding | L14-20, L14-30 | |
| L15 | 3-phase 250 V | 3 pole, 4 wire | Grounding | L15-20, L15-30 | |
| L16 | 3-phase 480 V | 3 pole, 4 wire | Grounding | L16-20, L16-30 | |
| L17 | 3-phase 600 V | 3 pole, 4 wire | Grounding | L17-30 | |
| L18 | 3-phase wye 120/208 V | 4 pole, 4 wire | Non-grounding | L18-20, L18-30 | |
| L19 | 3-phase wye 277/480 V | 4 pole, 4 wire | Non-grounding | L19-20, L19-30 | |
| L20 | 3-phase wye 347/600 V | 4 pole, 4 wire | Non-grounding | L20-20, L20-30 | |
| L21 | 3-phase wye 120/208 V | 4 pole, 5 wire | Grounding | L21-20, L21-30 | NEMA’s own example: one cord for 208 V heaters plus a 120 V receptacle points to an L21-20.1 |
| L22 | 3-phase wye 277/480 V | 4 pole, 5 wire | Grounding | L22-20, L22-30 | |
| L23 | 3-phase wye 347/600 V | 4 pole, 5 wire | Grounding | L23-20, L23-30 |
What mates with what
- A receptacle takes the plug of its own configuration. Bryant: a 5-15R accepts only a 5-15P.11
- The stated exceptions: a 5-20R also accepts a 5-15P, and both the 5-15R and 5-20R accept a two-blade 1-15P.11
- Different ratings do not interchange. NEMA cites UL 498 clause 15.3.5: plug and receptacle configurations of different ratings must be non-interchangeable.1
- OSHA’s workplace standard says the same of the devices: receptacles, cord connectors and attachment plugs shall be constructed so that no receptacle or cord connector will accept an attachment plug with a different voltage or current rating than that for which the device is intended. The one allowance is a 20 ampere T-slot receptacle or cord connector taking a 15 ampere plug of the same voltage rating.16
- If the plug does not fit, the ratings do not match. Do not file a blade, pull a ground pin or reach for an adapter. The equipment needs a circuit and receptacle of its own rating. That is a licensed electrician’s job.
Field notes
Where the published charts disagree
We read five manufacturers’ charts against each other and against NEMA’s own FAQ paper. The ratings above are the ones at least two publishers agree on. These are the misprints we found on the way. If your wall chart shows one of them, the wall chart is wrong.
- NEMA WD 11-2023, page 13, prints 5-20R as 15 A, 250 V and 6-15R as 15 A, 125 V. Its own page 10 gives the 6-15 as 15 A, 250 V, and every manufacturer chart gives 5-20 as 20 A, 125 V and 6-15 as 15 A, 250 V.1 2 6
- Hubbell’s 2025 configuration chart prints series 10 as 215/250 V. Hubbell’s 2017 chart, Bryant and Eaton print 125/250 V.17 2 4 6
- The same 2025 Hubbell chart labels several plug cells with the wrong designation, for example 7-30P beside 10-30R and L24-30P beside L23-30R.17
- 7-20 is drawn in the Bryant chart with no catalog numbers, left blank in the Hubbell 2017 chart and listed by Eaton. Bryant’s FAQ says the missing catalog numbers are not a misprint: Bryant does not make a 7-20.4 2 5 11
What this chart is built from
The configuration standard is ANSI/NEMA WD 6, Wiring Devices: Dimensional Specifications. Bryant confirms WD 6 covers both straight blade and locking devices. This page is not built from the WD 6 dimension drawings. It is built from the manufacturers’ published configuration charts, their catalogs and product pages, and NEMA WD 11-2023. Use it to identify a device and confirm a rating. Do not use it to dimension one.11 1
Sources
- National Electrical Manufacturers Association. NEMA WD 11-2023, Wiring Devices: Frequently Asked Questions. 2023.
- Hubbell Wiring Device-Kellems. NEMA Straight Blade Devices (catalog configuration chart). 2017.
- Hubbell Wiring Device-Kellems. NEMA Twist-Lock Devices (catalog configuration chart). 2017.
- Bryant Electric, a Hubbell brand. Bryant Configuration Chart, BCM8003. 2012.
- Eaton. Wiring Devices Buyers Guide, Introduction: NEMA configurations for select devices, pages 9 to 14. 2025.
- Eaton. Wiring Devices Buyers Guide, Section Q Technical Reference, rating table page Q-12. 2025.
- Eaton. Wiring Devices Buyers Guide, Section A Straight blade devices, pages A-61 to A-85. 2025.
- Eaton. Color Coded Locking Devices NEMA selector guide (Arrow Hart), SA630015EN. November 2019.
- Legrand, Pass & Seymour. Plugs and Connectors brochure, BR1325, page 15: NEMA Configurations Locking Plugs and Receptacles. October 2013.
- Leviton. Industrial Wiring Devices Product and Solution Catalog. 2023, revised 2024.
- Bryant Electric, a Hubbell brand. Frequently Asked Questions. Read October 1, 2026.
- Hubbell Wiring Device-Kellems. Spec sheet HBLTT30R: 2-Pole 3-Wire Grounding, 30A 125V, TT-30R. Revised June 2026.
- Leviton. Product page 279: 50 Amp, 125/250 Volt, NEMA 14-50R flush mounting receptacle. Read October 1, 2026.
- Legrand, Pass & Seymour. Product pages 3894 (14-50R), 3894WR (14-50R weather resistant) and 3830WR (TT-30R). Read October 1, 2026.
- Hubbell Wiring Device-Kellems. Product page HBL303NM: marine grade hull inlet, 30A 125V, L5-30P. Read October 1, 2026.
- OSHA. 29 CFR 1910.305(j)(2)(ii), Wiring methods, components, and equipment for general use. eCFR, current as of September 30, 2026.
- Hubbell Wiring Device-Kellems. NEMA Configuration Chart, EP-WDK-CG-EN-02887. 2025.
- Eaton. Wiring Devices Product knowledge guide, MZ610009EN, page 77. September 2020.
- Legrand, Pass & Seymour. Product page PS-3894WREV: 50A weather resistant outlet for EV chargers, NEMA 14-50R. Read October 1, 2026.
- Leviton. Product page 830-E: 30 Amp, 125 Volt, NEMA TT-30P plug. Read October 1, 2026.