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The difference between three-phase power supply and single-phase power supply.

The difference between three-phase power supply and single-phase power supply.

January 21,2023

The power supply from the generator is three-phase, each phase of the three-phase power supply and its neutral point can form a single-phase loop to provide as a group of single phase power energy . The AC circuit here can not be called positive or negative pole, should be called line end (civil power called live line) and neutral line (civil power called neutral line).

For the mostly big industrial dehumidifier like SDI-480L, SDI-960L are three-phase. While the home dehumidifier like SDP-58L SDP-90L, and grow dehumidifier SDD-150L, SDD-240L are single-phase. It is OK to custom make machines with different phase requirement. 

Normally the neutral line of three-phase civil power supply should not be grounded at the entry end (grounded at the transformer end, this grounding is to take into account that the suspension point can not cause a higher point than the power supply voltage, the grounding of the user and transformer ground in the earth is a certain resistance). The power supply mode is a live wire and a neutral wire (neutral point lead line) constitute a circuit, in the single-phase three-core power jack is also connected with a ground wire. But this ground wire is not from transformer, it is from ground.

But for three phase dehumidifier, the three phase power supply should be with neutral line. If your three phase power supply is without neutral line. Please let us know in advance so that we can custom make the dehumidifiers.

This is to take into account the realization of the function of the leakage protector, (the working principle of the leakage protector is: If the human body touches the wire end of the power supply that is the live wire, or the electric leakage inside the electrical equipment, then the current from the live wire through the human body living electrical equipment shell into the earth, and does not flow through the neutral line, the current of the live wire and the neutral line will not be equal, the leakage protector detects the difference in this part of the current immediately trip to protect the safety of the human body and electrical equipment, the general choice of the differential current in dozens of milliamps) if, The neutral point of the power supply is directly grounded (which is not allowed in the construction of civil electricity), the leakage protector will lose its function, can not protect the human body and the short circuit of electrical equipment. 


The colors of three-phase electricity are yellow for phase A, green for phase B, and red for phase C. There are currently several names: A, B, C or L1, L2, L3 or U, V, W, in the same order.


The total power of three-phase electrical appliances is equal to the voltage of each phase multiplied by the current of each phase multiplied by the square root of 3, that is, the total power = current × voltage (220V) ×√3 (p=I×U×√3)

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