Locking Receptacle, L21-30R, 30 A, 120/208V AC, Three Phase, 4 Pole, Flush Mount, Screw Terminals

The HUBBELL 30A Isolated Ground Locking Receptacle is an industrial-grade device rated for use in electrical connections in commercial and industrial settings. This flush-mount, twist-lock receptacle features isolated ground construction to separate the grounding contacts from the mounting strap, suitable for applications requiring isolated ground construction. It accommodates 4 poles and 5 wires with a NEMA L21-30R configuration and is rated for 120/208V AC three-phase power at up to 30 amps.

Key Features of the HUBBELL 30A Isolated Ground Locking Receptacle:

• Isolated Ground: Insulation barrier construction isolates ground contact from mounting strap; green screw connects directly to grounding contacts.


• Amperage & Voltage Rating: Rated for 30 A, 120/208V AC, three-phase operation.


• NEMA Configuration: L21-30R with twist-lock design.


• Wiring Capability: Accepts #16 AWG – #8 AWG solid or stranded copper wire via screw terminals; supports both back and side wiring.


• Material Construction: Brass contacts and all-brass mounting system


• Rated operating temperature range: -40°C to +75°C (without impact); maximum temperature rise of 30°C at full load after overload testing.


• Listings & Standards: Certified to UL 498, CSA C22.2 No.42, Federal Specification W-C-596; flammability rating V2 or better per UL94/CSA standards.


• Mounting Type: Flush mount with included screw hardware; standard size single-gang installation footprint.