NEMA L21-30 — 3ØY 120/208 V, 30 A Twist-Lock Plug & Receptacle
NEMA L21-30 is a twist-locking configuration per NEMA WD-6: 3ØY 120/208 V, 30 A, 4-pole 5-wire grounding. Three-phase distro — events, data centers. The receptacle is L21-30R, the matching plug L21-30P.
No free-licensed face diagram exists for this configuration yet — locking faces are not on Wikimedia Commons. The specs below still identify it unambiguously.
Specifications
- Configuration
- L21-30
- Series
- Locking (L / twist-lock)
- Voltage rating
- 3ØY 120/208 V
- Amp rating
- 30 A
- Poles / wires
- 4P–5W
- Neutral
- Yes
- Equipment ground
- Yes
- Max load (at rating)
- √3 × 208 V × 30 A = 10,808 VA
- Continuous (80%)
- 8,646 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
Three-phase distro — events, data centers. Family L21 overall: full wye — events, data centers, distro (l21-30). The locking blades twist in and cannot vibrate or pull loose — the reason generators, stage rigs, and equipment connections spec the L series over its straight-blade cousins.
RELATED CONFIGURATIONS
See every configuration on the full NEMA plug & receptacle chart →
Common questions
What is the difference between L21-30R and L21-30P?
The letter is the device: L21-30R is the receptacle (outlet), L21-30P is the plug on the cord. Both share the same configuration — 3ØY 120/208 V, 30 A, 4-pole 5-wire grounding, twist-locking blades.
Does NEMA L21-30 have a neutral and a ground?
Yes on the neutral — the 3ØY 120/208 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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