What is the TN-S Three-phase Five-wire System?

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The TN-S three-phase five-wire system is a common power supply system. The following will introduce it from aspects such as its definition, composition, characteristics, and application scenarios:

### Definition and Basic Structure
In TN-S, "T" indicates that the neutral point of the power source is directly grounded, "N" means that the exposed conductive parts of electrical equipment are grounded through the neutral wire, and "S" represents that the working neutral wire (N wire) and the protective neutral wire (PE wire) are completely separated. In the TN-S three-phase five-wire system, there are three phase wires (L1, L2, L3), one working neutral wire (N wire), and one protective neutral wire (PE wire). The three phase wires are used to transmit electrical energy, the working neutral wire provides a circuit for single-phase loads, and the protective neutral wire is specifically used for safety protection.

### System Composition
- **Phase Wires**: Namely L1, L2, and L3. The voltage between them is the line voltage, usually 380V, and they are used to supply power to three-phase electrical equipment. In a three-phase balanced load, the vector sum of the three-phase currents is zero; while in a three-phase unbalanced load, the vector sum of the three-phase currents is not zero, and there will be current flowing through the working neutral wire.
- **Working Neutral Wire (N Wire)**: It forms a circuit with the phase wires and provides a current path for single-phase loads. In the case of three-phase imbalance, current will flow through the working neutral wire. Its potential is the same as that of the neutral point of the power source. Under normal circumstances, the voltage of the N wire to the ground is zero.
- **Protective Neutral Wire (PE Wire)**: It is not used to carry working current but only to connect the exposed conductive parts of electrical equipment, such as the equipment housing. Its function is to introduce the fault current into the ground when the equipment has a leakage fault, protecting the safety of personnel and equipment. During normal operation, there is no current on the PE wire, and the voltage to the ground is zero.

### Characteristics
- **High Safety**: Since the PE wire and the N wire are completely separated, when an electrical equipment leaks electricity, the leakage current will quickly flow into the ground through the PE wire, making the potential of the leaked equipment's housing close to the ground potential, thus avoiding the risk of electric shock to personnel. At the same time, it can also effectively prevent the phenomenon of the equipment housing being charged due to N wire faults or three-phase imbalance.
- **Strong Anti-interference Ability**: The N wire is mainly used to transmit working current, and the PE wire is used for safety protection. Separating the two can reduce the electromagnetic interference between electrical equipment and improve the stability and reliability of the system. Especially for some equipment sensitive to electromagnetic interference, such as computers, communication equipment, etc., the TN-S system can better ensure their normal operation.
- **Convenient Fault Troubleshooting**: When a fault occurs in the system, the type and location of the fault can be relatively easily determined by detecting the N wire and the PE wire. For example, if the PE wire is found to be charged, it is likely that the equipment has a leakage fault; while if the voltage of the N wire is abnormal, it may be due to three-phase load imbalance or an open circuit in the N wire itself.

### Application Scenarios
- **Residential Buildings**: It is widely used in the power supply systems of residential buildings, providing power for various household appliances, lighting equipment, etc., and can effectively ensure the safety of residents' electricity use. For example, the metal housings of home appliances such as refrigerators, washing machines, and air conditioners are all grounded through the PE wire to prevent electric shock accidents caused by leakage.
- **Commercial Buildings**: Such as shopping malls, office buildings, etc. There are a large number of electrical and electronic devices in these places. The TN-S three-phase five-wire system can not only meet the power supply requirements of different types of loads but also ensure the safety of electricity use and the stable operation of equipment.
- **Industrial Production**: In industrial places such as factories and workshops, various motors, production equipment, etc. have high requirements for the reliability and safety of power supply. The TN-S system can provide a stable power source for these devices and provide effective protection when the equipment fails, reducing the occurrence of accidents.#tiktokrefugee#cat#tiktokban#china#抖音难民#transformer#singlephase#transformer#autotransformer#transformation#power#supply#maintenance#inverter#cabinets#EV charger#load break switch#ring main unit#Prefabricated Substation#Gas insulated switchgear#Medium Voltage Switchgear#power distribution box#PowerDistribution #SubstationTransformer #ElectricalEngineering #PowerTechnology #TechReview # 1500kVA #wankongPower 761 #wankongtransformer #transformer #electrical #technology #factory #foryou #viral #shortvideo #manufacture #machine #power #shorts #trending #wiring #factorywork #electricalengineering #powertransformer