How To

Installing a New Shore Power Cord End

Use this guide to easily replace the cord ends on your shore power cable.

By Capt. Vincent Daniello

Updated: April 19, 2016

Shore power cables last for decades, but cord ends often fail sooner from internal corrosion, high amperage that occurs either from a lightning strike or low voltage at a marina, or from a short common if a charged cord end is dropped in the water. “Look for burn marks around terminals or pitting on the blades that show it’s been arcing, or any signs of corrosion” says Joe DiMaria from Hubbell. Either problem will, sooner or later, cause that cord’s connections to fail. Also check the cord end’s mating receptacle on the dock or boat, as a faulty receptacle can short a cord end, or vice-versa. Look for corrosion in and on the back of that receptacle, too, as it’s a common place for the ground connection to fail.

Before Beginning Make Sure The Cable Is Unplugged

For a 50-amp, 240-volt cord shown here, cut the damaged end off with a hacksaw. Capt. Vincent Daniello

Cut the yellow boot along its markings to fit your shore cord’s diameter. Capt. Vincent Daniello

Slide the weatherproof boot and metal two-piece connector body onto the cord. (Tip: A bit of KY Jelly helps slide the rubber compression fitting over the cord.) Next, strip the outer yellow jacket back 1 1/2 inches, being careful not to nick the inner wires. Strip those inner 6-gauge wires back 3/4 inch. (Tip: cut the green ground wire half an inch shorter than the other three.) Capt. Vincent Daniello

Adjust the depth of the blade on this cable stripper to remove the outer yellow jacket without nicking the inner-wire insulation. Capt. Vincent Daniello

To strip heavy 6-gauge wire on 50-amp cords, cut the inner wire insulation, cut and then and then split the insulation with a utility knife. (#10 wire on 30-amp cords is much easier to strip using ordinary wire strippers.) Capt. Vincent Daniello

Twist those wire ends tight and insert them neatly into the wire funnels and ground clamp within the plug body — red wire to X, black to Y, white to W. Capt. Vincent Daniello

Tip: To ensure proper polarity of red and black hot wires, plug the insert into the opposite (working) end of the shore cord and check polarity of red to X and black to Y with a multimeter. Capt. Vincent Daniello

Mark the black prong with a sharpie for easy identification during assembly. Capt. Vincent Daniello

Use a 1/4-inch-blade screwdriver to tighten those screw clamps snug, and go back and tighten them again a few minutes later. Loose screws create plug-burning heat at high amperage. Capt. Vincent Daniello

Slide the plug insert into its metal housing, tucking the grounding tab in as you do. Capt. Vincent Daniello

Turn the insert clockwise slightly to lock it in place. Capt. Vincent Daniello

Tighten the three screws that assemble the connector. Capt. Vincent Daniello

Tighten the clamp onto the yellow outer wire jacket. Slide the protective boot onto the metal cord end assembly. Capt. Vincent Daniello

30-amp cord ends install similarly, although they’re easier since they have only three wires and don’t require an outer metal body to ground the cord. Capt. Vincent Daniello

Materials List (boatownerswarehouse.com)
Male 50-amp 240-volt cord end (shown in photos)
Hubbell HBL63CM65 complete assembly $107
HBL77CM16 yellow weatherproof boot $25

Female 50-amp 240-volt cord end
Hubbell HBL63CM64 complete assembly $121
HBL77CM15 yellow boot with ring $40

30-amp 120-volt shore cord replacement ends
Male end Hubbell HBL26CM11 $32
Yellow boot HBL60CM31 $17
Female end HBL26CM13 $64
Yellow boot with ring $24 HBL60CM33