What is the phase voltage of the three alternating current lines?
The voltage between each phase line (FireWire) and the neutral line (zero line) in the three-phase AC circuit is called the phase voltage, and its RMS value is expressed by UA, UB, UC. The voltage between the phase lines is the effective value Expressed in UAB, UBC, UCA. Because the three-phase AC power supply of the three coils of the AC voltage phase difference of 120 °, three coils for star connection, the phase voltage is equal to the root of the line voltage 3 times. We usually talk about the voltage is 220 volts, 380 volts, is the three-phase four-wire power supply phase voltage and line voltage. China's daily circuit, the phase voltage is 220V, line voltage is 380V (380 = root number 3 × 220). Engineering, the discussion of three-phase power supply voltage size, usually refers to the power line voltage. Such as three-phase four-wire power supply voltage 380V, refers to the line voltage 380V.
The cable has no formula: but can calculate the weight, the weight is mainly inside the conductor, the conductor weight is completely calculated, the cross-sectional area * length * density conductor outside the insulation, sheath, filler, etc. is not good to calculate The
It can be used for voice system termination, can also be used as a data system termination
The control cable is divided into two types: power type and signal type. The operating voltage is also divided into high pressure type (within 1000 volts) and low pressure type (within 200 volts) High pressure type for wire power transmission instruction Low pressure type for low-voltage electronic equipment command signal transmission! Including within 127 volts of control power transmission! Practical work commonly known as control cable and signal cable!
