How to Connect Inlet Wires for Container Houses

The inlet wires for container houses generally adopt a five-wire system, and it is necessary to connect the live wires, neutral wires, and ground wires according to the type of distribution box. The specific operations are as follows:

I. Inlet Wire Types and Wiring Systems The inlet wires for container houses usually use a five-wire system, which includes three phase wires (A, B, C, colored yellow, green, and red respectively), one neutral wire (light blue), and one ground wire (yellow with green stripes). This wiring system is suitable for power distribution boxes and can meet the power demands of both 220V and 380V loads. For example, a 220V load requires one phase wire, one neutral wire, and one ground wire; a 380V load (such as an AC motor) requires all three phase wires plus a ground wire; and for special two-phase 380V equipment (such as an AC welder), any two phase wires plus a ground wire can be used.

II. Distribution Box Types and Wiring Methods

1. Air Switch Distribution Box:
   • Connect the inlet wires to the upper terminals of the main switch and operate according to the terminal markings on the switch. Connect the live wire to the L terminal and the neutral wire to the N terminal, adopting a "left neutral, right live" layout.
   • The neutral wire needs to be connected to the neutral bar, and the ground wire to the ground bar to ensure electrical isolation and safety.
2. Power Distribution Box:
   • The three-phase inlet wires are connected through a 3PIN or 4PIN circuit breaker. The neutral wire is crimped onto the neutral terminal block, and the ground wire is crimped onto the ground terminal block.
   • If a 4PIN circuit breaker is used, the three phase wires and the neutral wire enter together, and the ground wire is crimped separately onto the ground bar.

III. Key Precautions

1. Ground Wire Connection:
   • The ground wire must be reliably connected to the ground bar, especially in humid or outdoor environments, to prevent the risk of electric leakage. Although grounding may be omitted in temporary scenarios such as construction sites, container houses, as long-term or semi-permanent buildings, require mandatory grounding to comply with electrical safety regulations.
2. Wire Diameter and Load Matching:
   • Select an appropriate wire diameter according to the power of the electrical equipment. For example, high-power equipment (such as air conditioners and motors) requires thicker wires to avoid overheating and potential fires.
3. Waterproof and Moisture-Proof Treatment:
   • The inlet ports of container houses need to be sealed to prevent rainwater from seeping in and causing short circuits. It is recommended to use waterproof connectors or sealant to fill the gaps.
4. Professional Tools and Acceptance:
   • Use an insulation resistance meter to test the grounding resistance and ensure it is ≤4Ω; use a multimeter to check the voltage stability.
   • After the wiring is completed, conduct a power-on test to check whether each circuit is working normally without abnormal heating or sparks.