Knowing the power of the motor, how to estimate the rated current How big is the ammeter and transfo

The formula for calculating the rated current of the motor is: i = p ( 3 V power factor efficiency).

Among them, P is the rated power of the motor, V is the rated voltage of the motor, and the power factor and efficiency are generally the rated values.

The choice of ammeter and transformer needs to be decided based on the measurement needs.

You can directly select the appropriate straight-through ammeter, and if you need to make remote measurements or need to read the measured values frequently, you can consider choosing a transformer to use with the ammeter.

The selection of transformer needs to choose the appropriate model according to the size of the measured current, while considering the voltage level, insulation material, environmental factors, etc.

Motor power refers to the output power. The power calculated from voltage and current refers to the input power. The output power is divided by the efficiency to get the input power.

Therefore, the correct formula for calculating the rated current is:

i=p/η/√3/u/cosφ。

In the above formula: is the rated efficiency, and cos is the rated power factor.

Generally speaking, the higher the power of the motor, the higher the rated efficiency, and the higher the rated power factor. These parameters are generally marked on the motor nameplate.

At present, the efficiency of high-efficiency motors above 15kw can be estimated by 90 95%, and the power factor can generally be estimated.

Take the 55kw motor as an example, estimate (calculate) the rated current:

For this reason, the rated current per kW is estimated to be 2A, the transformer should be selected 200 5, and the ammeter should also be selected 200 5 for supporting applications.

Take the 55kw motor as an example, estimate (calculate) the rated current:

For this reason, according to the estimated rated branch flow of 2A per Menghong kW, 200 5 for the transformer, and 200 5 for the electric rot section flow meter should also be selected for supporting applications.

It is known that the leakage rate of the motor power family is 250kw, the rated voltage is 6kv, the transformation ratio of the electric zhaozi current transformer is 50 5, and the rated current is. What is the current of the zero search sequence.

Dear users, according to the information you provide, we can calculate the size of the zero sequence current. First, according to the conversion ratio of the current transformer, the rated current is converted to a current in the main circuit of 1520A (. Secondly, according to the motor power and rated voltage, the rated current of the motor can be calculated to be 250000W (6kV*).

Finally, according to the principle of symmetrical combination, the zero sequence component of the three-phase current is the algebraic sum of the three-phase current divided by 3, that is, Brother Fan i0=(ia+ib+ic) 3. Therefore, substituting the rated current of the motor and the current in the main circuit into the formula, the magnitude of the zero sequence current can be obtained as (ia+ib+ic). It should be noted that due to the specific wiring method of the motor and the characteristics of the power supply system, the actual zero sequence current may be different.

Hello, glad to answer for you. 7 sets of 10kw motors, power stupid grasp factor, find how large capacity transformer and energy meter to choose, the calculation formula is the following low-voltage three-phase 1kw current of about 2a, according to the current to determine the transformer rated current. For example, 50kv, 50 2 = 100, so choose 100 5 transformer.

For example, 75kw, choose 150 5 transformer. For example, 80kw, 200 5 transformers can be selected (i.e. the lowest specification transformers greater than 160A). Hope mine can help you!

Do you have any other questions for advice?

It is known that the rated power is p=132kw, the voltage u=380v, and the current i=260a.

The actual voltage is 410V, and the current cannot be controlled at 260A

Calculation formula: i p

The exact calculation formula is: i p (, i.e., the rated current is the motor power divided by the root number 3, then divided by the motor voltage, then divided by the power factor, and then divided by the efficiency.

The three-phase asynchronous motor consists of two basic parts: a fixed stator and a rotating rotor, which is housed in the stator cavity and supported on two end caps with the help of bearings. In order to ensure that the rotor can rotate freely in the stator, there must be a gap between the stator and the rotor, called an air gap. The air gap of the motor is a very important parameter, and its size and symmetry have a great impact on the performance of the motor.

Figure 2 shows the components of a three-phase cage asynchronous motor.

Summary. Solve the problem input power = rated power power power factor efficiency. Workaround and Procedure Steps:

1.First of all, it is necessary to determine the power rating, power factor and efficiency of the asynchronous motor, which can be obtained from the nameplate of the motor. 2.

Then, according to the calculation formula of the input power, the input power = rated power factor efficiency, the rated power, power factor and efficiency are substituted into the formula to find the input power. 3.Finally, based on the results of the calculations, the input power of the motor can be determined.

Related knowledge: power factor refers to the ratio of the actual power of the motor under the rated load to the rated power, which reflects the efficiency of the motor, in general, the larger the power factor, the higher the efficiency of the motor. Efficiency refers to the ratio of the actual power of the motor under the rated load to the input power, which reflects the energy utilization rate of the motor, in general, the higher the efficiency, the higher the energy utilization rate of the motor.

Solve the problem input power = rated power power power factor efficiency. Workaround and practice steps:1

First of all, it is necessary to determine the power rating, power factor and efficiency of the asynchronous motor, which can be obtained from the nameplate of the motor. 2.Then, according to the calculation formula of the input power, the input power = rated power power due to lease leakage efficiency, the rated power, power factor and efficiency are substituted into the formula to find the input power.

The power factor refers to the ratio of the actual power of the motor under the rated load to the rated power, which reflects the efficiency of the motor, in general, the larger the power factor, the higher the efficiency of the motor. Efficiency refers to the ratio of the actual power of the motor under the rated load to the input power, earlier it reflects the energy utilization rate of the motor, in general, the higher the efficiency of the land oak, the higher the energy utilization rate of the motor.

I'm sorry I don't understand, but can you elaborate on that?

To solve this problem, we can use the following formula to calculate the input power: input power = rated power factor efficiency. The asynchronous motor is a commonly used motor, which is characterized by the fact that it can work under different load conditions and the output power can be adjusted.

Its power factor and efficiency are important parameters of the motor, and they can affect the performance of the motor. The power factor is the ratio of the active power of the motor to the apparent power, which can reflect the load state of the motor, generally speaking, the larger the power factor, the better the load state of the motor. Efficiency is the ratio of the output power of the motor to the input power, it can reflect the energy efficiency of the motor, generally speaking, the higher the efficiency, the better the energy efficiency of the motor.

Therefore, we can calculate the input power based on the power rating, power factor, and efficiency of the asynchronous motor. Through the calculation, we can derive the magnitude of the input power, so as to better control the operating state of the motor.

The rated current of 100kw of power is i=p ampere.

Choose a current transformer of 200 5.

Choose an ammeter of 200 5.

Select a circuit breaker for 300A.

Choose a 400A AC contactor.

Wiring: If it is a close distance (within a few tens of meters), the copper wire is 50 square millimeters, and the aluminum wire is 90 square millimeters.

If it is a long distance (more than 100 meters), the copper wire is 95 square millimeters, and the aluminum wire is 150 square millimeters.

If it is between close and long distance, the copper wire is 70 square millimeters and the aluminum wire is 120 square millimeters.

The rated current of the 380V three-phase asynchronous motor is about 2A per kilowatt, and the rated current of 132KW is about 260A, if you want to control the current at 260A, you must control the load, let the motor run at 260A, and the rated current of 315kW is about 620A.

The rated current of the 132kw motor is about 260A, and if the actual mechanical load is less than the rated value, the load current is also lower than 260A; It is not allowed that the load current is greater than 260A for a long time (slightly greater than a short period of time is allowed).

Calculation formula: i p

The rated current of the 380V three-phase asynchronous motor can be estimated according to the motor power x2, which is the rated current of the motor.

The exact calculation formula is: i p (, i.e., the rated current is the motor power divided by the root number 3, then divided by the motor voltage, then divided by the power factor, and then divided by the efficiency.

Under normal circumstances, the rated current of the 132kw motor is less than 260A, the voltage increases, and the current is smaller, but if the motor works in an overload state, and the motor power factor or efficiency is too low, it may cause the current to rise, so if you want to control the current, you must limit the motor not to overload, and the power factor and efficiency can not be too low.

You need to provide the parameters of the nameplate on the motor to calculate.