NEMA Configurations
Straight blade and locking (twist-lock) receptacle configurations with specs and wiring.
17 reference items · 3 sections
Straight Blade Configurations
NEMA 5-15 — 125V, 15A (Standard Household)
NEC 406.4
The standard U.S. household outlet. Two vertical parallel blades + U-shaped ground.
NEMA 5-15 Specifications
| Property | Value |
|---|---|
| Voltage | 125V |
| Current | 15A |
| Poles | 2 |
| Wires | 3 (Hot, Neutral, Ground) |
| Grounding | Yes |
| Hot (Brass screw) | Black wire |
| Neutral (Silver screw) | White wire |
| Ground (Green screw) | Green/bare wire |
Most common receptacle in residential and commercial applications. Required by NEC 406.4(A) to be grounding type.
NEMA 5-20 — 125V, 20A
NEC 210.52
20-amp rated outlet. One T-shaped neutral slot accepts both 15A and 20A plugs.
NEMA 5-20 Specifications
| Property | Value |
|---|---|
| Voltage | 125V |
| Current | 20A |
| Poles | 2 |
| Wires | 3 (Hot, Neutral, Ground) |
| Neutral Slot | T-shaped (accepts 5-15 plugs) |
| Common Use | Kitchen, bath, garage, outdoor |
Required in kitchens, bathrooms, laundry, garages, and outdoors. Must be on a dedicated 20A circuit for kitchen countertops.
NEMA 5-30 — 125V, 30A
NEC 406.4
30-amp 125V outlet. Less common but used for specific high-current 120V equipment.
Voltage: 125V
Current: 30A
Wires: 3 (Hot, Neutral, Ground)
Typical Use: Some industrial 120V equipment, water heaters
NEMA 6-15 — 250V, 15A
NEC 406.4
15-amp 250V outlet. Two horizontal parallel blades + U-ground.
Voltage: 250V
Current: 15A
Wires: 3 (Hot, Hot, Ground — no neutral)
Typical Use: Small 240V equipment, window A/C units
NEMA 6-20 — 250V, 20A
NEC 406.4
Two horizontal parallel blades + U-ground. Used for 240V equipment (window A/C units, some power tools).
Voltage: 250V
Current: 20A
Wires: 3 (Hot, Hot, Ground — no neutral)
Hot wires: Black and Red
Ground: Green/bare
NEMA 6-30 — 250V, 30A
NEC 406.4
Similar to 6-20 but rated for 30A. Used for some welders and larger 240V equipment.
Voltage: 250V
Current: 30A
Wires: 3 (Hot, Hot, Ground — no neutral)
Typical Use: Welders, commercial equipment
NEMA 6-50 — 250V, 50A (Welder Outlet)
NEC 406.4
Common welder outlet. Two horizontal blades (hot-hot) + U-ground.
Voltage: 250V
Current: 50A
Wires: 3 (Hot, Hot, Ground)
Typical Use: Welders, large power tools
NEMA 10-30 — 125/250V, 30A (Old Dryer)
NEC 250.140
Legacy 3-prong dryer outlet (no ground). No longer permitted in new installations.
Voltage: 125/250V
Current: 30A
Wires: 3 (Hot, Hot, Neutral — NO ground)
Status: Existing installations grandfathered; new work requires NEMA 14-30
NEMA 14-30 — 125/250V, 30A (Modern Dryer)
NEC 250.140
Modern 4-prong dryer outlet with separate ground.
Voltage: 125/250V
Current: 30A
Wires: 4 (Hot, Hot, Neutral, Ground)
Typical Use: Electric clothes dryers
Required: For all new dryer installations since 1996
NEMA 14-50 — 125/250V, 50A (Range/EV)
NEC 422.10
4-prong range outlet, also commonly used for EV charging.
Voltage: 125/250V
Current: 50A
Wires: 4 (Hot, Hot, Neutral, Ground)
Typical Use: Electric ranges/ovens, EV chargers (Level 2)
Locking (Twist-Lock) Configurations
NEMA L5-20 — 125V, 20A Locking
Twist-lock plug prevents accidental disconnection.
Voltage: 125V
Current: 20A
Wires: 3 (Hot, Neutral, Ground)
Typical Use: Portable generators, temporary power, commercial
NEMA L5-30 — 125V, 30A Locking
Common generator outlet.
Voltage: 125V
Current: 30A
Wires: 3 (Hot, Neutral, Ground)
Typical Use: RV parks, portable generators, transfer switches
NEMA L6-20 — 250V, 20A Locking
240V locking outlet for industrial equipment.
Voltage: 250V
Current: 20A
Wires: 3 (Hot, Hot, Ground)
Typical Use: Industrial equipment, data centers
NEMA L6-30 — 250V, 30A Locking
Common in data centers and commercial applications.
Voltage: 250V
Current: 30A
Wires: 3 (Hot, Hot, Ground)
Typical Use: Server racks, UPS systems, industrial equipment
NEMA L14-30 — 125/250V, 30A Locking
Most common generator outlet for portable generators.
Voltage: 125/250V
Current: 30A
Wires: 4 (Hot, Hot, Neutral, Ground)
Typical Use: Portable generators, transfer switches, RV parks
NEMA L21-30 — 3Φ 120/208V, 30A Locking
Three-phase locking connector for commercial power distribution.
Voltage: 120/208V 3-Phase
Current: 30A
Wires: 5 (A, B, C, Neutral, Ground)
Typical Use: Temporary power, events, construction sites
Quick Reference — Most Common
Most Common NEMA Configurations
Common NEMA Configurations at a Glance
| NEMA | Voltage | Amps | Wires | Common Use |
|---|---|---|---|---|
| 5-15 | 125V | 15A | 3 | Standard outlet |
| 5-20 | 125V | 20A | 3 | Kitchen/bath/garage |
| 5-30 | 125V | 30A | 3 | High-current 120V |
| 6-15 | 250V | 15A | 3 | Small 240V equip |
| 6-20 | 250V | 20A | 3 | Window A/C |
| 6-50 | 250V | 50A | 3 | Welder |
| 10-30 | 125/250V | 30A | 3 | Old dryer (legacy) |
| 14-30 | 125/250V | 30A | 4 | Modern dryer |
| 14-50 | 125/250V | 50A | 4 | Range / EV charger |
| L5-30 | 125V | 30A | 3 | Generator |
| L14-30 | 125/250V | 30A | 4 | Generator (240V) |
1.First digit = NEMA config group, second = amp rating
2.L prefix = Locking (twist-lock) type
3.Configs 1-5: 125V | 6: 250V | 10,11: 125/250V (3-wire) | 14,15: 125/250V (4-wire)
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