Complete reference for NEMA receptacle/plug configurations and standard wire color codes. Covers residential, commercial, and industrial electrical systems.
Based on NEC 2023 Article 406, 200.6, 250.119
Standard NEMA connector designations for receptacles and plugs. Locking types are indicated with an "L" prefix.
Standard household (non-grounding, legacy)
Standard 15A household outlet
Standard 20A outlet (kitchen, bathroom)
Window A/C, power tools
Dryer (old), welder
Welder, sub-panel feed
Electric dryer (old, no ground)
Range (old, no ground)
Electric dryer (modern)
Range/oven (modern)
Twist-lock 20A general purpose
Twist-lock 20A, server/IT equipment
Twist-lock 30A, PDU, industrial
EV charger, large equipment
Generator transfer switch, portable generators
Commercial 3-phase 30A
| NEMA | Voltage | Amps | Phase | Wires |
|---|---|---|---|---|
| 1-15 | 125V | 15A | 1φ | 2P/3W |
| 5-15 | 125V | 15A | 1φ | 2P/3W |
| 5-20 | 125V | 20A | 1φ | 2P/3W |
| 6-20 | 250V | 20A | 1φ | 2P/3W |
| 6-30 | 250V | 30A | 1φ | 2P/3W |
| 6-50 | 250V | 50A | 1φ | 2P/3W |
| 10-30 | 125/250V | 30A | 1φ | 3P/3W |
| 10-50 | 125/250V | 50A | 1φ | 3P/3W |
| 14-30 | 125/250V | 30A | 1φ | 3P/4W |
| 14-50 | 125/250V | 50A | 1φ | 3P/4W |
| 14-60 | 125/250V | 60A | 1φ | 3P/4W |
| L5-20 | 125V | 20A | 1φ | 2P/3W |
| L6-20 | 250V | 20A | 1φ | 2P/3W |
| L6-30 | 250V | 30A | 1φ | 2P/3W |
| L14-30 | 125/250V | 30A | 1φ | 3P/4W |
| L21-30 | 120/208V | 30A | 3φ | 4P/5W |
Standard wire color identification per NEC 200.6 (Neutral), 250.119 (Ground), and common industry practice for phase conductors.
NEMA connector designations follow a standard pattern that tells you everything about the connector at a glance.
An "L" prefix indicates a twist-lock connector (e.g., L14-30). These are used where vibration or accidental disconnection is a concern: generators, industrial equipment, and commercial installations.
The first number (1, 5, 6, 10, 14, etc.) indicates the voltage and pole configuration. For example: 5 = 125V 2-pole, 6 = 250V 2-pole, 14 = 125/250V 3-pole with ground.
The number after the dash indicates the maximum ampere rating. Common ratings are 15A, 20A, 30A, 50A, and 60A.
2P/3W = 2 poles, 3 wires (hot-hot-ground or hot-neutral-ground). 3P/4W = 3 poles, 4 wires (hot-hot-neutral-ground). 4P/5W = 4 poles, 5 wires (3-phase + neutral + ground).
NEMA 14-30 is the modern standard (since NEC 1996) with a separate ground wire. NEMA 10-30 is a legacy 3-wire configuration without a dedicated ground. New installations must use 14-30.
Most Level 2 EV chargers use NEMA 14-50 (50A, 240V) or are hardwired. Some use NEMA 6-50 (no neutral). Tesla Wall Connectors are typically hardwired on a 60A circuit. NEMA 14-60 is used for higher-power installations.
Twist-lock connectors prevent accidental disconnection. Use them for generators (L14-30), data centers (L6-20/L6-30), temporary power, and any application where vibration or movement could pull a plug loose.
Yes, but you must limit the ampacity to the 75°C column per NEC 110.14(C). The 90°C rating is used for derating calculations only. Use our Wire Size Calculator to handle this automatically.
IMPORTANT LEGAL DISCLAIMER
For Reference Only: This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional engineering design, advice, or certification.
Code Compliance: Calculations are based on the 2023 National Electrical Code (NEC®). However, local codes, amendments, and Authority Having Jurisdiction (AHJ) requirements vary by location and may supersede standard NEC requirements.
Verify with Your AHJ: Local Authority Having Jurisdiction (AHJ) requirements take precedence over all general code references. Contact your local building department or electrical inspector to confirm applicable codes, amendments, and permit requirements before beginning any electrical work.
No Liability: SparkShift, LLC and its affiliates assume no liability for errors, omissions, or the use/misuse of this tool. Users are solely responsible for verifying all results against applicable codes and standards before installation. Always consult a licensed electrician or Professional Engineer (PE).
NEC Reference: NEC 2023 Article 406, 200.6, 250.119
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