Blue Sea 3001 HD-Series On/Off Battery Switch with AFD

The Blue Sea Systems 3001 HD-Series Single Circuit On/Off Battery Switch with Alternator Field Disconnect is rated 600A continuous.

Six hundred amps is the highest continuous rating in the HD-Series, above the 500A of the 3002 and 3003. That extra capacity suits a large diesel with substantial house loads, where the difference between 500 and 600 amps is the margin the installation actually needs rather than a specification nobody reaches.

Alternator field disconnect breaks the field circuit before the main contacts open, so the alternator is never switched off-load. Doing that to a charging alternator destroys its diodes, and the damage is not obvious until the batteries stop charging some time later.

Each terminal accepts two 4/0 battery cables on 1/2-inch M12 tin-plated copper studs with extended length for multiple terminals. Tactile knob textures identify position by feel, the mounting pattern fits common Perko and Guest layouts, and it is ignition protected and meets ABYC requirements. Explore more battery switches.

• 600A, the highest in the HD-Series
• AFD stops the alternator being switched off-load
• Switching off-load destroys alternator diodes
• Two 4/0 cables per terminal on M12 studs