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)

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

Learn more.

Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

Learn more.

Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

Learn more.