Blue Sea Systems CableCap Stud Insulator, PVC, Single Stud

Overview

The Blue Sea Systems CableCap is a PVC stud insulator for covering a single exposed termination stud on boat electrical equipment. It is made for stud-type connectors on alternators, starters, windlasses, and other high-amperage termination points where an uncovered live post can be a problem in tight electrical spaces.

This CableCap range covers multiple stud and cable sizes, with red and black versions available for installations that use color separation around DC positive and negative circuits. Across the family, the listed cable sizes run from 18 AWG through 4/0 AWG, so the correct variant should be matched to the terminal, cable size, and stud diameter being protected.

Key features

• Insulates a single stud-type connector on alternators, starters, windlasses, and other high-amperage devices.
• PVC construction gives the cap a practical insulating body for marine DC electrical installations.
• Red and black color options support clear visual separation in electrical lockers, battery compartments, and engine spaces.
• Variant range covers cable sizes from 18 AWG to 4/0 AWG, depending on the selected cap.
• Stud size options include 0.47 to 0.13, 0.70 to 0.30, 0.50, and 1.25 to 0.70, allowing the cap to be matched to the termination point rather than forced onto the wrong hardware.
• Useful for reducing accidental contact with exposed high-current studs in crowded marine electrical areas.

Variants

The CableCap range varies by color and by the stud size range it is meant to cover. Red and black versions are available across the common size groups, which helps keep the installation easy to identify after panels, covers, or battery cables are reinstalled.

The variants also differ by cable size coverage, with smaller caps for 18 to 10 AWG and 8 to 4 AWG wiring, mid-size caps for 2 to 2/0 AWG wiring, and larger caps for 3/0 to 4/0 AWG wiring. Match the cap to the actual stud and cable size on the alternator, starter, windlass, bus connection, or other high-current termination before installation.

Installation and fit

Check the terminal stack before fitting the cap, especially where a lug, washer, nut, and additional hardware share the same stud. The cap should cover the exposed conductor area without putting strain on the cable or interfering with the tightened connection.

On boats, these caps are most often used in spaces where tools, loose gear, battery boxes, or nearby metalwork could contact a live stud. They are a simple fit-and-protect item for DC refits, battery cable upgrades, windlass wiring, engine-room service work, and cleanup of exposed high-current posts.

Compatibility and use on board

This product is a good match for boat owners, installers, and service technicians working around high-current DC terminations that need a cleaner and safer insulated finish. It is not a network connector or a voltage-specific electronic component, so fit is determined by the physical stud, terminal, and cable size rather than by NMEA compatibility or 12V versus 24V system voltage.