400A Dual-Pole DC Protection Box for a Delong / Leapton lithium battery

400A Dual-Pole DC Protection Box for Delong, Leapton or High-Capacity Batteries – Ready for Installation

The 400A protection box for Delong, Leapton or industrial lithium battery banks is a high-power, turnkey solution for securing your large-scale energy storage installations. This box provides comprehensive bipolar protection, simultaneously isolating the positive and negative terminals to ensure maximum safety against massive overloads and short circuits with high breaking capacity.

Enclosure contents

This enclosure is supplied complete and pre-wired with industrial-grade components:

• Reinforced IP65 enclosure: A robust enclosure offering total protection against dust and water spray, designed for heat dissipation.
• 2P 400A DC double-pole circuit breaker: Industrial circuit breaker (MCCB type) enabling the simultaneous and safe disconnection of both polarities under heavy load.
• 2 x 1 m 150 mm² cables with terminals: Ultra-high-performance connection to the inverter to support 400A continuously.
• 2 x 1 m 150 mm² cables with terminals: Optimised connection for linking your high-capacity battery banks to the enclosure without overheating.

How the cabinet works

The cabinet is designed to centralise and protect high-intensity energy flows:

• The batteries are connected to the cabinet via the 150 mm² cables, minimising electrical resistance.
• Bipolar protection: The 2P 400A circuit breaker acts instantly on both lines (+ and -), ensuring that no residual current flows during an emergency shutdown or maintenance.
• The current is then distributed via 150 mm² cables to the DC input of the power inverter.

Safety principle: At 400A, the stored energy is considerable. By switching off both poles simultaneously, this enclosure provides true galvanic isolation, protecting the user and the power electronics from electric arcs and major insulation faults.

Typical applications

• Commercial or industrial installations with high-capacity Delong/Leapton battery banks.
• Large-scale storage systems with parallel connection of multiple battery banks.
• Main protection for high-power inverters in off-grid sites or self-consumption systems with storage.

Compatible hybrid inverters

• Deye: Three-phase range from 15kW to 50kW.

Advantages of the 400A enclosure

• High-power bipolar safety: Simultaneous disconnection of the (+) and (-) terminals, essential for high-energy-density systems.
• XL cabling (150 mm²): Cross-section calculated to prevent any energy loss and any fire risk associated with cable overheating.
• Ready to use: Significant time savings on site (crimped terminals, cables supplied).
• Industrial robustness: Equipment rated for intensive discharge cycles.

Commissioning

1. Check that the 400A circuit breaker is in the OFF position.
2. Connect the 150 mm² cables to the battery terminals (observe the tightening torques).
3. Connect the 150 mm² cables to the DC inputs of the inverter.
4. Carefully check the polarity (+ red, - black) before carrying out any work.
5. Set the circuit breaker to the ON position to activate the power connection.

Safety and maintenance

• 2P 400A circuit breaker: Thermal (slow overload) and magnetic (short-circuit) protection on both poles.
• IP65 rating: Protection against moisture and dusty environments.
• CRITICAL maintenance: At 400A, loose connections can cause a fire. You must check the tightness of the terminals 24 hours after commissioning, and then annually.