Container House Diagonal Grounding

Diagonal grounding of container houses is aimed at forming an equipotential grounding network to ensure electrical safety and reduce the risk introduced by potential differences.

I. The Role of Diagonal Grounding

The main purpose of diagonal grounding for container houses is to ensure that the container body and its internal equipment are at the same potential as the earth, preventing electrical accidents caused by potential differences. By setting grounding points at the diagonal positions of the container, a more stable grounding path can be formed, reducing the grounding resistance (required to be no more than 4Ω), thereby effectively discharging static charges and fault currents.

II. Specific Grounding Requirements

1. Location and Quantity of Grounding Points
   The container should provide at least 2 grounding points that meet power standards in the form of copper bars, and these points should be located at the diagonal positions of the container. This layout can expand the grounding range and reduce the impact of potential differences on the equipment.

2. Grounding Materials and Connection Methods

   • A 250mm² dedicated grounding copper bar should be laid inside the container and fixed with insulating terminals to form an equipotential grounding network.
   • Electrical equipment should be connected to its own 100mm² grounding copper bar using a 4mm² yellow-green bicolored grounding wire, and then connected to the equipotential network inside the container through a 100mm² copper cable.
   • The connection between copper bars should be lap-jointed, with a length no less than twice the width, and fixed with 6mm diameter bolts.

3. External Connection Requirements
   The exterior of the container body should be connected to the main grounding network at a single point through a 250mm² grounding copper bar or more than 4 copper strip cables with a cross-sectional area of no less than 50mm², and equipped with copper bolts with a diameter of no less than 10mm. Multi-point connections are strictly prohibited to avoid introducing potential differences from the main grounding network into the container.

III. Significance of Safety and Protection

1. Anti-electric Shock Protection
   After grounding, fault currents preferentially flow into the earth through low-resistance grounding conductors, significantly reducing the risk of electric shock when personnel come into contact with charged enclosures.

2. Static Electricity Protection
   Anti-static floors (with a system resistance of 1×10⁶~1×10⁹Ω) are laid inside the container, and in combination with the equipotential grounding network, they can effectively discharge static electricity, preventing static electricity from causing breakdowns or performance impacts on the integrated circuits of electronic equipment (such as BMS and PCS control boards).

3. Fire Prevention and Equipment Protection
   Standardized grounding can prevent fires caused by electrical faults (such as the container fire caused by a switch circuit fault in a reference case) and ensure the stable operation of equipment.