# Maximum current

## Basic Case

The maximum operating current of the motor is a working current that the motor can work for a long time, which can generally reach 1.2 times the rated current, generally due to improper design of the design power, resulting in motor selection Small, but in the case of exceeding the rated power, the motor can continue, at which time the operating current is the maximum operating current, the start current of the motor is started at the start of the motor = blocking current = maximum current, the three is the same value . For common Y-series three-phase asynchronous motors, the start current is 5.5 to 7.0 times, different power, and different power, and different speeds of different speeds. The maximum instantaneous current three-phase alternating current is 1.732 times the rated current, and the two-phase alternating current is 1.414 times.

The maximum short circuit current is after the device is extremely current, before the speed is quickly disconnected, the current does not have the largest instantaneous tolerant of the equipment to the equipment.

Rated maximum current: The device allows the maximum current to operate long-term operation while satisfying accuracy, security, and reliability.

Rated maximum current of the copper wire:

2.5 square millimeter copper power line Safety load flow - 28A. 4 square millimeter copper power cord safety load flow - 35A.

6 square millimeter copper power line Safety load flow - 48A.

10 square millimeter copper power cord safety load flow - 65A.

16 square millimeter copper power line safety load flow - 91a.

25 square millimeter copper power cords. Safety load flow - 1220a. If it is an aluminum wire, the wire diameter should be 1.5-2 times the copper wire.

If the copper wire is less than 28A, it will be sure safe at 10A per square millimeter 10a.

If the copper wire is greater than 120A, take it at 5A per square millimeter.

## Effective current is

Under the specified conditions, the maximum efficient current value of continuously flowing can be continuously flowed, and I f . There are two types of valid values ​​and average value. For a general two-way diode, a two-way semiconductor gate tube such as a two-way diode, a semiconductor gate tube such as a silicon symmetry switch is a semiconductor gate flow tube that flows through the current for a general controllable silicon rectifier or the like. The average value as described below is used.

Since the effective value is proportional to its heat, regardless of whether the waveform of the AC current is sine wave, the controllable silicon rectifier that can flow through the sinusoidal wave 1 can also flow, or the pulse waveform or Any other waveform of 1 An electric current. That is, it is not necessary to consider the difference in its waveform.

## Average current

Under the specified cooling conditions, the average value of the maximum current value of the thyristor to continuously energize in a period is referred to as a rated forward average current. I f , generally means that the sinusoidal conduction angle is 180 °. As can be seen from the average average value and valid value, the average is 2 / π-fold of a valid value. Of course, the average and valid values ​​are equal when direct current. In the product manual, the average current and function of the average current and the highest allowable bolt temperature (usually means the average temperature rise) of the various conduction angles are often listed in the product specification. This rated value is generally only available in the 50-400 HCIM. That is, the frequency is too low or too high, which allows current values ​​that flow through the thyristor rectifier to be reduced.

Related Articles