Overview

The Perko 9604DP is a medium duty main battery disconnect switch for 6 to 32 volt marine electrical systems, with a built-in alternator field disconnect and key lock. It is ignition protected, rated for 250 amps continuous and 360 amps intermittent, and uses a surface-mount body that measures 5-1/4 inches in diameter and 2-5/8 inches deep.

On board, this switch handles the basic job of isolating battery power when the boat is shut down, while also giving you a keyed lockout when you want the system left off. The field-disconnect circuit is there for charging systems that use a field wire, which helps reduce the chance of alternator damage if the switch is turned off with the engine running.

Key features

• For 6 to 32 VDC marine electrical systems
• 250 amp continuous rating and 360 amp intermittent rating
• Ignition protected for installation in gasoline engine spaces
• Built-in alternator field disconnect for charging systems that use a field wire
• Key lock secures the switch in the OFF position, with key removal available in the locked or unlocked position
• Polycarbonate body with brass terminals and 5/16 inch terminal studs
• Surface-mount form with a 5-1/4 inch diameter and 2-5/8 inch depth

Compatibility and fit

This switch suits boats that need a main battery shutoff rather than a battery selector. It works across 12V, 24V, and 32V systems within its 6 to 32 volt range, and the ignition-protected construction makes it suitable for spaces around gasoline engines where that matters.

The 5/16 inch studs are sized for ring-terminal cable connections, and the terminal length can accommodate more than one cable when the installation calls for it. On boats with large battery cables, it is worth checking rear clearance behind the mounting surface before final placement.

Installation and setup

This is a surface-mount switch, so the chosen location should leave enough room for cable bend radius behind the panel or bulkhead. Keeping battery cables as short as practical helps limit voltage drop, and terminal connections in wet or corrosive spaces should be protected after wiring is complete.

The field-disconnect feature applies to charging systems that use a separate field connection. On single-wire alternators, the switch can still be used as the main battery disconnect, but that field-disconnect function is not part of the installation.

Use on board

This is a good match for boats that want one clear OFF and ON battery isolation point with keyed lockout, such as center consoles, small cruisers, workboats, and sailboats with a simple house or start battery shutoff. It also fits installations where the switch needs to sit near the engine or in another machinery space that calls for ignition protection.