Automatický nabíjecí relé ML-ACR - 12 V DC 500 A

The BLUE SEA ML-ACR 500A (reference PN 7620) is a robust automatic charging relay designed for demanding marine and automotive applications. It manages two battery banks by automatically combining them during charging and isolating them when no charge is detected. This model can handle high-efficiency alternators and large battery banks thanks to its continuous capacity of 500 amperes.

The Magnetic Latching (ML) technology is a key feature of the ML-ACR 500A relay. It ensures extremely low current consumption when the relay is in the ON or OFF state. The relay only draws moderate current during the very short period when it changes state (approximately 20 ms), which optimizes battery life by reducing continuous current draw.

The ML-ACR 500A offers configurable isolation functions to protect sensitive onboard electronics:

Start Isolation (SI): Temporarily protects house loads from the engine circuit during engine start, preventing voltage drops and spikes. Engine Isolation (EI): Allows isolation of two running engines to protect their electronics and maximize alternator output. Note that the ML-Series ACR can be configured for either Start Isolation or Engine Isolation, but not both simultaneously.

The ML-ACR 500A relay automatically combines battery banks when the detected voltage reaches:

Above 13.5V for 30 secondsAbove 13.0V for 90 secondsIt automatically isolates the battery banks when the detected voltage drops to:

Below 12.35V for 10 secondsBelow 12.75V for 30 seconds

The ML-ACR 500A relay integrates protections against extreme voltages for 12V DC operation:

Undervoltage Lockout: Prevents battery combining when one battery is below 9.6V.
Overvoltage Lockout: Prevents battery combining when one battery is above 16.2V.
These mechanisms protect the relay from overvoltages and high peak currents, as well as batteries from excessive discharge or overcharging.

Yes, the ML-ACR 500A relay is designed for durability in harsh environments. It is rated IP66, meaning it is protected against dust and powerful water jets. Additionally, it features tinned copper studs for maximum conductivity and corrosion resistance, as well as silver alloy contacts for high reliability when switching loads under load.

No, the ML-ACR 7620-BSS model is designed for fully automatic operation and does not include integrated manual control. The PN 7622 and PN 7623 models from the ML-ACR series are the ones that feature manual control.

The control circuit of the ML-ACR 500A relay has a current consumption of less than 40 mA.

The ML-ACR 500A standard (PN 7620) is optimized for AGM/GEL to AGM/GEL or AGM/GEL to Lithium battery configurations. For systems using lithium batteries in Lithium-to-Lithium or Lithium-to-Lead-Acid configurations, the ML-ACR Li-Ion version is recommended, specifically designed for these applications.

No, the ML-ACR 500A model (PN 7620) is specifically designed for 12V DC systems. Other models in the ML-ACR series (e.g., PN 7621 or PN 7623) are designed for 24V DC systems.

Yes, the ML-ACR 500A is designed to support high-efficiency alternators and large battery banks. Its continuous capacity of 500A allows it to efficiently manage power distribution and optimize charging performance even under demanding conditions.

The ML-ACR 500A can be controlled remotely using a Contura three-position switch (SPDT) (ON-OFF-AUTO). This type of switch allows forcing battery bank combinations, isolating them, or letting the relay operate in automatic mode. A momentary switch (SPDT) (ON)-OFF-(ON) or a momentary push button can also be used to ensure cross-connection and/or battery isolation.

To ensure the ML-ACR 500A relay reaches its continuous rated capacity of 500A, it is recommended to use 2x 4/0 AWG cables (2x 120 mm²). This wiring will handle a starting current of 1450A (30 sec) and an intermittent current of 700A (5 min).

The ML-ACR 500A is equipped with 3/8"-16 terminal studs. The recommended maximum tightening torque for these studs is 140 in-lb (15.8 N•m). It is essential to respect this torque to ensure a secure connection and prevent damage to the relay.

The ground wire of the ML-ACR 500A must be connected to a common ground or directly to the negative terminal of the battery. A correct ground connection is essential for the proper operation of the relay.

The ML-ACR 500A relay provides an LED output to remotely indicate the battery status. If the remote switch LEDs are off, the batteries are isolated. If the LEDs are on, the batteries are combined. Specific LED flashes also indicate states such as start/engine isolation, under-voltage lockout, or over-voltage lockout.

The physical dimensions of the ML-ACR 500A relay are as follows:

Width: 3.75" (95.3 mm)
Height: 5.47" (138.9 mm)
Depth: 2.03" (51.6 mm)

The configuration of Start Isolation (SI) or Engine Isolation (EI) depends on how the inputs are wired. The detailed instructions provided with the product describe the specific wiring diagrams for each function. Note that the relay can be configured for either function, but not both simultaneously.

Yes, the ML-ACR 500A relay is ignition-protected. It is certified to meet external ignition protection requirements per ISO 8846 and SAE J1171 standards, making it safe for use in engine compartments where flammable vapors may be present.