How to Ground Container Houses

Grounding container houses requires meeting resistance requirements, following installation specifications, and considering usage scenarios. Here are the specific methods:

I. Basic Grounding Requirements

The grounding resistance must be less than 4 ohms, which is the core indicator for ensuring safety. Regardless of the scenario, the grounding resistance value must be tested and meet the standard using professional instruments; otherwise, the depth of the grounding electrode must be adjusted or the number increased.

II. Installation Steps and Material Selection

1. Digging Pits

   • In ordinary areas, dig to a depth of 2.5-3 meters, avoiding frozen soil layers; in areas with high thunderstorm frequency, dig to 4-12 meters until reaching groundwater to enhance conductivity.
   • Charcoal or salt can be laid at the bottom of the pit to reduce soil resistivity.

2. Material Selection

   • Grounding Electrodes: Preferably use galvanized steel pipes (diameter ≥ 50mm) or angle steel with a thickness of 5 centimeters, which have strong corrosion resistance;
   • Connecting Wires: Use yellow-green bicolored copper wires with a cross-sectional area of more than 4 square millimeters. The use of bare wires or iron wires is prohibited to avoid poor contact due to oxidation.

3. Installation Operations

   • Bury at least 2 grounding electrodes, spaced 3-5 meters apart, and at least 1.5 meters away from the house;
   • The metal frame of the container must be firmly welded, and the door should have a separate grounding wire. Apply anti-rust paint to the welding points;
   • The top of the grounding electrode should be at least 0.6 meters above the ground to prevent human damage.

III. Special Requirements for Different Scenarios

1. With Electrical Equipment

   • Both lightning protection grounding and electrical protection grounding must be done simultaneously, with a grounding resistance ≤ 4Ω;
   • Use galvanized flat steel or copper rods buried at least 1.5 meters underground and welded to the metal frame;
   • Install residual current circuit breakers, and add lightning protection devices in humid or thunder-prone areas.

2. Temporary Construction Site Dormitories

   • If used only for storage or temporary rest without electrical appliances, grounding may not be required, but ensure there are no exposed wires;
   • For long-term use or in humid environments, grounding is still recommended.

3. Long-term Office/Residence

   • Grounding is mandatory, and residual current circuit breakers should be installed in humid or thunder-prone areas;
   • Regularly check if the grounding wires are aging or broken.

IV. Other Key Considerations

1. Construction Specifications: Grounding must be carried out by professional electricians to avoid false connections or corrosion;
2. Regular Testing: Test the resistance every six months, once in spring and once in autumn, and retest after moving;
3. Lightning Protection Treatment: Connect the outer wall of the container to the grounding device using conductive materials such as copper sheets or copper mesh to ensure tight contact;
4. System Maintenance: Clean dirt from the surface of the grounding device, check if the connection points are loose, and form a continuous grounding network.