250A protective box for Delong battery
250A protective box for Delong battery
250A protective box for Delong battery
250A protective box for Delong battery

250A Bipolar DC Protection Box for Delong Lithium Batteries

€434.33
Tax included
Coffret-protection-250A-Delong
0768563823817

The DC 250A bipolar protection box is the central safety component for your energy storage systems. Designed specifically for Delong batteries (48V / 100Ah and above), this box ensures total isolation by simultaneously disconnecting the positive (+) and negative (-) poles.

The major advantage of this bipolar protection is its ability to completely isolate the circuit: unlike conventional protection, it ensures that no residual current flows during shutdown, thus protecting the user and the inverter from electric arcs and insulation faults. This device is essential for preserving the life of your lithium cells in the event of overloads.

Equipped with a robust 250A circuit breaker, it can withstand current peaks without overheating. Its omnipolar manual cut-off allows you to work on the installation with complete peace of mind.

Technical advantages:

  • Bipolar safety: Simultaneous cut-off of (+) and (-) for true galvanic isolation.
  • 250A rating: Ideal for high-power discharges from lithium battery banks.
  • Full protection: Thermal and magnetic tripping on both poles.
  • Robust design: IP65 waterproof enclosure suitable for demanding environments.
  • Ready to use: Internal terminal blocks for large cross-section cables (up to 95mm²).

250A Bipolar DC Protection Box for Delong Batteries – Ready to Install


The 250A protection box for Delong batteries is a turnkey solution for securing your energy storage installations. This box provides complete bipolar protection, simultaneously isolating the positive and negative poles to ensure maximum safety against overloads and short circuits.





Box contents

This box is delivered complete, pre-wired and ready to install:

  • IP65 box: Robust box offering total protection against dust and water splashes.
  • 2P 250A DC1000V bipolar circuit breaker (TOMZN - TOM7Z): The central safety device allowing simultaneous disconnection of both polarities.
  • 2 x 1 m 95 mm² cables with terminals: Secure and optimised connection to the inverter. 
  • Four 50 mm² cables, 1.50 m long, with terminals: High-performance connection for connecting your Delong battery packs to the cabinet.





How the box works

The box is designed to centralise and protect the direct current reliably:

  • Delong batteries are connected to the box via the 4 x 50 mm² cables.
  • Bipolar protection: The 2P 250A circuit breaker acts on both lines (+ and -), ensuring that no residual current flows in the event of a power cut.
  • The two 95 mm² cables then distribute the power in a stable manner to the inverter.

Safety principle: By cutting both poles simultaneously, this bipolar cabinet provides true galvanic isolation, protecting the user and the inverter's electronics from any insulation faults.





Typical applications

  • Residential or professional installations equipped with Delong lithium batteries.
  • Modular storage systems mounted in parallel requiring safe isolation.
  • Bipolar protection essential for hybrid PV installations and isolated sites.





Advantages of the box

  • Bipolar safety: Simultaneous isolation of (+) and (-) for increased protection.
  • Turnkey solution: Box, high-section cabling and circuit breaker included.
  • Quick installation: Internal terminal blocks and cables pre-fitted with terminals.
  • DC compliance: Equipment specifically calibrated for high-intensity direct currents (250A).
  • Safe maintenance: Allows the battery bank to be completely isolated during maintenance work.





Commissioning

  1. Check that the bipolar circuit breaker is in the OFF position.
  2. Connect the 95 mm² cables to the Delong battery terminals.
  3. Connect the 50 mm² cables to the DC inputs of the inverter.
  4. It is essential to observe the polarity (+ red, - black) on both poles of the circuit breaker.
  5. Set the circuit breaker to the ON position to power up the installation.





Safety and maintenance

  • 2P 250A circuit breaker: Resettable magnetic and thermal protection on both poles.
  • Optimised cabling: 95 mm² and 50 mm² cross-sections to minimise voltage drops and heating.
  • IP65 rating: Suitable for technical environments (battery rooms, garages).
  • Maintenance: Periodic checking of terminal tightness and testing of the circuit breaker release button.





FAQ - 250A Protection Box for Delong Batteries

1. Why is bipolar protection essential for my Delong batteries? +
Bipolar protection allows the positive (+) and negative (-) lines to be cut simultaneously. This is a vital safety feature for high-power lithium installations as it guarantees total galvanic isolation. In the event of a fault, no residual current can flow, thus protecting the inverter and the user from insulation faults.
2. Why does the box use two different cable sections (95 mm² and 50 mm²)? +
The 50 mm² cables are used to connect each Delong battery pack to the cabinet, a cross-section that is perfectly suited to the individual intensity of the modules. The 95 mm² cables are used for the main connection between the cabinet and the inverter, as they must withstand the cumulative current of 250A while minimising voltage losses and heating.
3. Is this cabinet ready for use upon delivery? +
Yes, it is a turnkey solution. The cabinet is delivered pre-wired with a 250A TOMZN circuit breaker already installed. The kit also includes 95 mm² and 50 mm² cables pre-fitted with terminals, which significantly reduces installation time and eliminates the need for special crimping tools.
4. Can I install this protective box outdoors? +
The box has an IP65 protection rating, making it completely dustproof and resistant to water splashes. It can therefore be installed in demanding technical environments such as a garage, battery room or protected outdoor shelter, while ensuring the safety of the internal equipment.
5. What should I do if the circuit breaker trips? +
The 250A bipolar circuit breaker is a resettable device. If it trips, this indicates an overload or short circuit. Identify and correct the cause of the fault in your UPS or battery installation before simply flipping the lever back up to restore power to the system.
6. What maintenance is required for this cabinet? +
For long-term safety, we recommend periodically checking that the terminals and terminal blocks are tight (charge/discharge cycles can cause slight thermal expansion). It is also advisable to manually test the circuit breaker once a year using its test button.
Coffret-protection-250A-Delong

Data sheet

Type of electrical equipment
Protection box

Specific References

UPC
768563823817
EAN13
0768563823817
MPN
Coffret-protection-250A-Delong

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