25ft NEMA L5-30P to L5-30R Locking Generator Cord, 10 AWG SJTW, 30A/125V Heavy Duty, Black

The NEMA L5-30P to L5-30R locking power cord is a heavy duty extension cord that carries 30 amps at 125 volts between a portable generator and the equipment, inlet box, or transfer switch it feeds. A twist-lock male plug on one end and a matching twist-lock female connector on the other create a secure, grounded connection that will not shake loose under load. The cord is built for users who need to move 30-amp 120-volt power a safe distance from the source.

The NEMA L5-30P plug is a 2-pole, 3-wire grounding twist-lock connector rated for 30A at 125V. It is the male end that inserts into the L5-30 outlet found on many portable generators and manual transfer switches. The locking design seats the blades and rotates them into a fixed position, which keeps the connection stable on a vibrating generator and protects the grounded circuit during continuous operation.

The NEMA L5-30R connector is the female counterpart and shares the same 30A 125V 2-pole 3-wire interface. Because both ends use the identical L5-30 interface, this product extends an existing L5-30 line rather than converting one connector type to another. It does not change voltage or pin configuration, so the cord delivers the same dedicated 30-amp feed at the far end that it receives at the source.

Three 10 AWG conductors give the cord the cross-section needed to carry a sustained 30-amp load without voltage drop or heat buildup over distance. The SJTW thermoplastic jacket is weather- and water-resistant and stays flexible in cold temperatures, so the cord holds up to outdoor generator runs, damp ground, and repeated coiling. The grounding conductor maintains a continuous safety path from the source to the connected equipment.

Portable generator owners make up the core use case, running power from a generator's L5-30 outlet to tools, pumps, or a distribution point. Homeowners with a manual transfer switch use the cord to feed a backup power inlet during outages. Marine and dock users connect 125V 30-amp pedestal power to boats and equipment. The locking connection matters most where vibration, weather, or foot traffic could otherwise pull a standard plug loose.

The black jacket provides a professional appearance and suits standard data center and enterprise rack deployments.

Compatibility & Ordering Information: This cord connects to any generator, inlet box, or transfer switch fitted with a NEMA L5-30 30A 125V twist-lock outlet. It does not plug directly into a 30-amp RV, which uses the TT-30 standard, or into a 4-prong L14-30 120/240V generator outlet; both of those require a separate adapter. The cord is available in multiple lengths to match the distance between your generator and load. For 30-amp RV service, pair it with an L5-30P to TT-30R adapter.

Product Comparison: NEMA L5-30 vs. TT-30 vs. L14-30

FAQ

What is the difference between a NEMA L5-30 cord and a TT-30 RV cord?

A NEMA L5-30 cord uses a twist-lock connector, while a TT-30 cord uses a straight blade plug for RV park pedestals. Both carry 30A at 125V, but the connectors are not interchangeable. L5-30 is standard on generators and transfer switches; to power a 30-amp RV you need an L5-30 to TT-30 adapter.

Is this cord compatible with my generator and my RV?

This cord fits any generator, transfer switch, or inlet box with a NEMA L5-30 30A 125V twist-lock outlet. It does not connect directly to a 30-amp RV, which uses a TT-30 inlet, so an L5-30P to TT-30R adapter is required. Confirm your generator outlet is L5-30 and not the 4-prong L14-30.

What gauge do I need for a 30-amp 125V cord, and how many watts does it carry?

A 30-amp 125V cord requires 10 AWG (10/3) copper conductors, which this cord uses. At 30A and 125V it carries up to 3,750 watts continuously. Lighter 12 or 14 AWG cords are not rated for a sustained 30-amp load and can overheat. The 10 AWG copper conductors also keep voltage drop low when the cord is run out to its full length.

How do I connect this twist-lock generator cord?

Align the L5-30P plug with the generator's L5-30 outlet, push in, and twist clockwise until it locks. Connect the L5-30R end to your equipment or transfer-switch inlet the same way. The locking action keeps the cord from vibrating loose during operation. Connect the cord before applying the load, and confirm both ends are fully seated and locked before starting the generator.

Which 30-amp cord should I choose, L5-30 or L14-30?

Choose L5-30 if your generator has a 3-prong 30A 125V twist-lock outlet and you run 120V equipment. Choose L14-30 if your generator has a 4-prong 30A 120/240V outlet. Matching the cord to your generator's outlet type is essential, because the two are not interchangeable. Check the label on the generator's outlet to confirm whether it is L5-30 or L14-30 before ordering.