NEMA 10-20 — 125/250 V, 20 A Plug & Receptacle
NEMA 10-20 is a straight-blade configuration per NEMA WD-6: 125/250 V, 20 A, 3-pole 3-wire non-grounding. Legacy non-grounding — rare. The receptacle is 10-20R, the matching plug 10-20P.
Face diagrams by Comrade Mmirg via Wikimedia Commons, CC BY-SA 4.0 / CC0, unmodified.
Specifications
- Configuration
- 10-20
- Series
- Straight blade
- Voltage rating
- 125/250 V
- Amp rating
- 20 A
- Poles / wires
- 3P–3W
- Neutral
- Yes
- Equipment ground
- No
- Max load (at rating)
- 250 V × 20 A = 5,000 VA
- Continuous (80%)
- 4,000 VA
Load figures are the arithmetic of the device rating at unity power factor. Continuous loads (3 hours or more) are limited to 80% of the circuit rating per NEC 210.19/210.20 — and the branch circuit behind the receptacle comes from the load calculation and conductor sizing, not from the plug face.
Where you meet it
Legacy non-grounding — rare. Family 10 overall: legacy dryer (10-30) / range (10-50), pre-1996. As a non-grounding configuration it survives only for replacements on existing circuits — new work uses the grounding successor family.
RELATED CONFIGURATIONS
See every configuration on the full NEMA plug & receptacle chart →
Common questions
What is the difference between 10-20R and 10-20P?
The letter is the device: 10-20R is the receptacle (outlet), 10-20P is the plug on the cord. Both share the same configuration — 125/250 V, 20 A, 3-pole 3-wire non-grounding.
Does NEMA 10-20 have a neutral and a ground?
Yes on the neutral — the 125/250 V rating means the circuit includes a grounded (neutral) conductor. It is a non-grounding configuration: no equipment ground, which is why new installations use its grounding successor.
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