Mersen 250A Battery Fuses and DC Disconnector – NH00 High Current Protection

This Mersen fuse and disconnector set provides essential overcurrent protection and isolation between the battery bank and inverter in off-grid and hybrid solar systems. The NH00 gL/gG fuses are rated for high continuous DC currents and are suitable for protecting lithium and lead-acid batteries in systems from 8kW upwards. The 250A disconnector allows safe isolation of the battery bank during maintenance or in an emergency.

Key Features

• 2x Mersen NH00 gL/gG DC fuses (200A or 250A, one for positive and one for negative battery pole)
• 1x 250A DC disconnector (isolator)
• Fuse enclosure included
• Suitable for lithium-ion and lead-acid battery banks
• Designed for high continuous discharge currents in solar inverter applications
• Suitable for inverters rated 8kW, 10kW, 11kW and above

Product Overview

In any off-grid or hybrid solar system, the cable between the battery bank and the inverter carries the highest continuous current in the installation. Correctly rated fuses on both the positive and negative conductors protect the battery bank and cabling against short-circuit and overcurrent faults. The DC disconnector allows the battery bank to be safely isolated from the inverter without needing to disconnect individual battery terminals, reducing the risk of arcing and electric shock during maintenance.

The NH00 fuse format is a standard industrial cartridge type widely used in European solar and energy storage installations. The enclosure and disconnector are designed to work together as a compact protection and isolation assembly, suitable for wall mounting in a plant room or electrical cabinet.

What Is Included

• 1x Fuse enclosure
• 2x Mersen NH00 gL/gG DC fuses (200A and 250A available, one for positive, one for negative)
• 1x 250A DC disconnector
• 1x Installation instructions

Applications

• Battery overcurrent protection in off-grid solar systems
• Hybrid inverter battery isolation and protection
• High current DC protection for inverters rated 8kW and above
• Lithium and lead-acid battery bank installations

Installation and Safety Notes

This protection assembly must be installed by a qualified electrician. DC circuits in solar battery systems carry dangerous voltages and high fault currents. Fuse selection must be matched to the cable rating and the maximum discharge current of the battery bank. Always isolate all power sources before working on DC connections. Install in accordance with IET Wiring Regulations and the inverter and battery manufacturers' guidelines.