Overview

The Perko 9703DP is a heavy duty battery disconnect switch with alternator field disconnect for 6 to 32 volt marine electrical systems. It is ignition protected and rated for 450 amps continuous with 1200 amps intermittent capacity for 15 seconds on and 5 minutes off.

This is an ON-OFF battery switch for boats that need one clear battery shutoff point rather than a selector. It can be mounted in engine rooms on gasoline-powered boats, and the alternator field disconnect helps protect alternator diodes if the switch is turned to OFF while the engine is still running.

The body is polycarbonate with brass terminals, and the 1/2 inch terminal studs give room for secure battery cable connections where more than one cable may need to land on the switch. The housing measures 5-1/4 inches square and 3-3/8 inches deep, which is useful when replacing an older Perko switch with the same mounting pattern.

Key features

• ON-OFF battery disconnect for 6, 12, 24, and 32 volt DC marine systems
• 450 amp continuous rating and 1200 amp intermittent rating
• Ignition protected for installation in engine rooms on gasoline-powered boats
• Alternator field disconnect with F1 and F2 terminals to break field current and reduce risk to alternator diodes
• Polycarbonate body with brass terminals and 1/2 inch terminal studs for heavy battery cable connections
• 5-1/4 inch square footprint, 3-3/8 inch depth, and the traditional Perko bolt circle for replacement work

Installation and setup

Battery disconnect switches work best when battery cables are kept as short as practical and sized for the load and cable run. On boats where the switch will be used near its continuous rating in an engine compartment, cable size and insulation temperature need to match the installation.

The alternator field disconnect circuit uses minimum 14 AWG wire suitable for marine engine compartments. On systems with a separate voltage regulator, that circuit is spliced into the field lead, so this switch fits installations where the alternator wiring can be reached cleanly during a refit or replacement.

Compatibility and fit

This switch is a good match for boats that need a main battery shutoff for storage, service work, seasonal layup, or emergency shutdown. It also makes sense in refit jobs where the existing bulkhead or panel already matches the Perko mounting pattern.

Because it is a disconnect switch, it suits battery isolation duty rather than multi-bank battery selection. That keeps the job simple on boats where the main requirement is to connect or disconnect the electrical system at one dependable point.