Automatic charge relay ML-ACR with manual control - 24 V DC 500 A

This BLUE SEA ML-ACR automatic charging relay (model 7623-BSS) is designed to operate with 24V DC electrical systems.

The ML-ACR 7623-BSS automatic charge relay has a DC current capacity of 500 amperes (A). It can also handle intermittent currents of 700A for 5 minutes and starting currents of 1450A for 30 seconds.

Magnetic Latch (ML) technology allows the relay to maintain its state (ON or OFF) with extremely low current consumption. This optimizes battery autonomy. Continuous consumption is less than 13mA and less than 7.0A during state changes.

The relay automatically combines battery banks when the charging voltage exceeds:

27.0V for 30 secondsOr 26.0V for 90 secondsThis ensures batteries are charged together when a charging source is detected.

The relay automatically isolates battery banks if the voltage drops below:

24.7V for 10 seconds or 25.5V for 30 secondsIt also isolates batteries in case of undervoltage (below 19.2V) or overvoltage (above 32.4V).

Yes, this ML-ACR model includes a manual control via a remote Contura switch (PN 2146). This provides an additional safety feature and allows manual operation even without power.

The Start Isolation (SI) function temporarily isolates the house battery loads from the engine circuit during engine start. This protects sensitive electronic equipment from voltage drops and spikes that can occur when the engine starts.

No, the ML-Series ACR can be configured for the Start Isolation (SI) function or the Engine Isolation (EI) function, but not both at the same time.

The relay includes lockout functions to protect the system:

Undervoltage lockout: Batteries are not combined if any one is below 19.2V DC. Overvoltage lockout: Batteries are not combined if any one is above 32.4V DC.

This relay uses 3/8"-16 tinned copper terminal studs. They provide maximum conductivity and excellent corrosion resistance, essential in a marine environment.

The BLUE SEA ML-ACR is designed to be robust in marine environments. It is rated IP66, meaning it is protected against powerful water jets. It also meets external ignition protection requirements per ISO 8846 and SAE J1171, and is CE marked.

The recommended maximum torque for terminal studs is 140 in-lb (15.8 N•m). It is important to respect this value to ensure a secure connection without damaging the relay.

For a continuous 500A capacity, it is recommended to use 2 cables of 4/0 AWG (2x 120 mm²). This ensures adequate and secure power distribution.

The included remote control switch features an LED indicator that provides a clear system status:

LEDs off: Batteries are isolated.LEDs on: Batteries are combined.LEDs slow-blinking: Start isolation or engine activated.LEDs fast-blinking: Lockout due to undervoltage or overvoltage.Double-blinking LEDs: Manual control activated or relay mechanical failure.

The standard ML-ACR (model 7623-BSS) is optimized for AGM/GEL to AGM/GEL and AGM/GEL to lithium configurations. However, it is not suitable for lithium-to-lithium or lithium-to-lead-acid configurations due to its predefined voltage thresholds. Blue Sea Systems offers a specific ML ACR Li-Ion version for these applications.

Yes, this ML-ACR automatic charge relay is designed to handle high-efficiency alternators and large battery banks, thanks to its 500A continuous capacity.

Blue Sea Systems supports its products for as long as you own them. This warranty reflects the manufacturer’s confidence in the durability and reliability of its equipment.

The relay ground wire must be connected to a common ground or directly to the battery's negative terminal. A correct connection is essential for proper system operation and safety.