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Black industrial watertight locking plug L21-30P 30A 120/208V 4P5W

Hubbell Incorporated

Hubbell Incorporated HBL28W81BK Watertight Locking Plug L21-30P 30A 120/208V 4P5W

SKU CH-PPH1-V99RA

Watertight locking plug rated 30 A, 120/208 V AC, three-phase with NEMA L21-30P configuration and screw terminals for cable diameters 0.375 to 1 in

  • TypeWatertight Devices
  • Watertight seal protects connections in wet environments
  • Three-phase 30 A rating powers heavy industrial loads
  • Chemical- and impact-resistant housing withstands harsh conditions
  • Screw terminals accept cable diameters from .375 in to 1 in
  • NEMA L21-30P configuration ensures correct polarized mating

Watertight Locking Plug L21-30P

This industrial-grade plug provides a secure three-phase connection for 30 A loads at 120/208V AC. It suits facilities that need reliable power distribution in wet or chemically harsh environments. The NEMA L21-30P configuration delivers four poles and five wires for balanced three-phase service.

Straight screw-terminal wiring

The straight orientation and screw terminals allow straightforward field termination without special tools. Installers must strip conductors to the correct length and torque each terminal to spec; loose screws or nicked strands are the most common causes of overheating. Cable diameter must stay between .375 in and 1 in to seat the grommet properly.

30 A three-phase capacity

The thermoplastic elastomer housing resists impact and chemicals while maintaining a watertight seal at the rated current. It comfortably handles continuous 30 A three-phase loads within the 120/208V rating. The device runs out of headroom if the load exceeds 30 A or if the supply voltage drifts outside the nominal range.

Highlights

  • Watertight seal protects connections in wet environments
  • Three-phase 30 A rating powers heavy industrial loads
  • Chemical- and impact-resistant housing withstands harsh conditions
  • Screw terminals accept cable diameters from .375 in to 1 in
  • NEMA L21-30P configuration ensures correct polarized mating

Specifications

BrandHUBBELL
TypeWatertight Devices

Questions about this item

How do I confirm the watertight locking plug is working correctly after wiring it?

Verify that the screw terminals hold each conductor firmly, the housing seals tightly around a cable between 0.375 in and 1 in diameter, and the L21-30P blades engage the matching receptacle with a secure locking action.

What comes with the HBL28W81BK plug and what must I supply separately?

The plug body with its thermoplastic elastomer housing and screw terminals is included; you must provide a 4-pole 5-wire cable sized for 30 A at 120/208 V AC and suitable strain-relief hardware.

Which NEMA configuration and amperage version should I select for a three-phase 30 A 120/208 V circuit?

Choose the L21-30P version, which provides four poles, five wires, three-phase polarised connections rated at 30 A and 120/208 V AC for industrial watertight applications.

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