Blue Sea Systems ML Solenoid Switch, 500A, Magnetic Latching

Overview

The Blue Sea Systems ML-Solenoid Switch is a 500A bi-stable magnetic latching solenoid for remote high-current DC switching on boats. It is used where a manual battery switch is not needed, but the circuit still needs to handle serious loads such as engine feeds, inverter circuits, house loads, or emergency battery combine service.

The latching coil draws 0A continuous current in the ON or OFF state and only uses power while the switch is changing state. Across the listed configurations, the solenoid carries a 500A continuous rating and a 700A intermittent rating for 5 minutes, with 3/8"-16 tin-plated copper terminal studs for large DC cables.

This is a practical fit for vessels that need remote control of a main DC circuit without adding constant coil draw to the battery bank. The IP66 rating, ignition protection, ISO 8846, and SAE J1171 compliance make it suitable for demanding marine electrical spaces where moisture, vibration, and engine-room safety matter.

Key features

• 500A continuous rating and 700A intermittent rating for 5 minutes, suitable for major DC loads such as engines, inverters, house circuits, and emergency battery combine circuits.
• Bi-stable magnetic latching coil draws 0A continuous current while ON or OFF, helping reduce standby drain on the battery system.
• Available in 12V DC and 24V DC nominal voltage versions to match common marine DC control systems.
• Control circuit options include Deutsch DTM / Amphenol ATM connector versions and tinned-wire versions for different wiring approaches.
• Silver alloy contacts support switching of live loads in high-current DC applications.
• 3/8"-16 tin-plated copper studs have a 0.875 in length and 1.18 in terminal ring clearance for large cable terminations.
• IP66, ignition protected, ISO 8846, and SAE J1171 ratings support use in damp marine electrical lockers and engine-room environments.
• Label recesses help keep circuit identification clear after installation.

Variants

This product is offered in four configurations for different control voltage and wiring preferences.

The differences are the nominal coil voltage and the control circuit connection. The 500A continuous rating, bi-stable coil function, no manual control, 3/8"-16 terminal studs, and included Contura remote control switch are consistent across the listed configurations.

• 7701100: Deutsch DTM / Amphenol ATM control circuit connection, 12V DC nominal voltage. This version suits 12V DC systems where connector-based control wiring is part of the installation plan.
• 7703100: Deutsch DTM / Amphenol ATM control circuit connection, 24V DC nominal voltage. This version matches 24V DC systems using connector-based control wiring.
• 7701: Tinned wire control circuit connection, 12V DC nominal voltage. This version fits 12V DC installations where the control leads are wired directly into the vessel harness.
• 7703: Tinned wire control circuit connection, 24V DC nominal voltage. This version fits 24V DC installations where direct control-lead wiring is preferred.

Electrical fit and installation

Use this solenoid in a properly sized DC system where the cable, overcurrent protection, and terminations are matched to the load. The cable size listed to meet ratings is 2x 4/0, and the terminal stud torque is 140 in-lb, so planning room for large cables, ring terminals, and service access is important before mounting.

The unit mounts with #10 fasteners and has no manual control at the solenoid body. It should be placed where remote switching makes sense, such as near a battery bank, inverter feed, or engine-room distribution point, while keeping the control switch accessible at the helm, electrical panel, or another operating station.

Use cases on board

This solenoid is a strong match for boats that need remote switching of high-current DC circuits without continuous coil draw. It works well in cruising boats, fishing boats, and workboats where battery banks, inverter loads, or engine-related DC circuits need to be managed from a protected control location.

Because the switch is latching and has no manual control, it is best used in systems where remote operation is intentional and the installation is clearly labeled for service. The label recesses help keep the circuit purpose visible, which is useful in crowded battery compartments and electrical lockers.

What's included

• SPDT Remote Control Contura Switch, (ON)-OFF-(ON)