NEMA 7-20 — 277 V, 20 A Plug & Receptacle
NEMA 7-20 is a straight-blade configuration per NEMA WD-6: 277 V, 20 A, 2-pole 3-wire grounding. 277 V lighting circuits. The receptacle is 7-20R, the matching plug 7-20P.
Face diagrams by Comrade Mmirg via Wikimedia Commons, CC BY-SA 4.0 / CC0, unmodified.
Specifications
- Configuration
- 7-20
- Series
- Straight blade
- Voltage rating
- 277 V
- Amp rating
- 20 A
- Poles / wires
- 2P–3W
- Neutral
- Yes
- Equipment ground
- Yes
- Max load (at rating)
- 277 V × 20 A = 5,540 VA
- Continuous (80%)
- 4,432 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
277 V lighting circuits. Blade geometry keys the voltage family physically: a plug from a different voltage class will not enter this receptacle.
RELATED CONFIGURATIONS
See every configuration on the full NEMA plug & receptacle chart →
Common questions
What is the difference between 7-20R and 7-20P?
The letter is the device: 7-20R is the receptacle (outlet), 7-20P is the plug on the cord. Both share the same configuration — 277 V, 20 A, 2-pole 3-wire grounding.
Does NEMA 7-20 have a neutral and a ground?
Yes on the neutral — the 277 V rating means the circuit includes a grounded (neutral) conductor. It carries an equipment grounding conductor (the extra wire beyond the poles).
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