About how to measure the resistance of an inverter fan motor

The master upstairs is talking about domestic air conditioners, and I am Daikin's air conditioners, which are different from domestic ones. The internal and external units are powered on, and the air conditioner first detects all parts of the internal and external units, and the external units are normal under normal conditions.

Zero line. The voltage between the communication line is normal within the normal range, if there is a component failure, the voltage between the neutral line and the communication line is not within the normal range, so that the internal machine will report the communication failure. Daikin's air conditioner, external compressor, external fan motor, solenoid valve coil, etc., if there is an abnormality, it will report a communication failure.

Daikin's air conditioner starts to detect communications when the machine is turned on and not running, while the domestic one is detected after the machine is running. Daikin's machines are self-tested at the beginning of start-up.

Friendly teachers! The resistance method is used to measure the quality of the motor, which is the first procedure of the repairer, which can identify the motor winding on and off. The pass side can be seen as good, and the broken side can be seen as bad; If there is a light short circuit between the winding and the winding turn, the resistance method is used to measure the quality of the motor, just like the way of netizens:

No way" also. Other methods must be adopted. Therefore, "almost impossible" and "can be measured" are both inaccurate, and have the meaning of "absolute".

Because the motor has its particularity.

What do you say? This is my humble opinion.

Available**.

The senior brother upstairs said well, I don't understand before I came here, at present, this air conditioner is because of the failure of the external fan motor and the internal and external units are not connected, and the replacement of the external motor fault is gone. When I brought the new motor, I compared the resistance measurement value with the faulty motor, and found that this type of motor is the same as the general 220V motor, and the three wires in the middle of the motor plug-in terminal can be measured, which is the same as other AC 220V motors.

Reply. Wild cassia.

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V-G-Friend, I'm not talking about identifying the degree of motor failure, but whether the quality of the DC motor can be measured by the resistance method.

This is a DC motor, you can only buy the original one, or change the AC motor and capacitor yourself.

1. The measuring instrument must have sufficient bandwidth:

With the continuous development of science and technology and the continuous strengthening of people's energy-saving concept, a large number of motor control systems have added inverters or drivers to drive the motor, so as to control the motor to produce different forces under different working conditions and avoid the phenomenon of big cows pulling trolleys. As we all know, the inverter works in chopping mode, constantly adjusting the high-frequency PWM wave to fit the sine wave. PWM frequency is generally in a few kHz to tens of kHz, so it is necessary to accurately measure the output parameters such as frequency converters, and the measuring instrument must have sufficient input bandwidth, generally speaking, the measurement bandwidth of the instrument must be 1MHz and above.

2. Accurate measurement of voltage and current values

High accuracy is the guarantee of accurate measurement efficiency, and the measurement accuracy of the PA series power analyzer can capture small dynamic characteristic changes in the efficiency evaluation test of the variable frequency motor drive system.

3. Accurately measure the phase difference of voltage and current

The PA series power analyzer uses a 100m synchronous clock with high stability temperature compensation to achieve synchronous sampling, and the synchronous sampling clock error is less than 10ns, which meets the extreme test requirements of the efficiency of high-performance variable frequency motor drive system.

Fourth, the input and output signals are measured synchronously.

The PA series power analyzer can perform the measurement of up to 6 power input channels + 1 motor input channel, so as to realize the synchronous measurement of inverter input-motor input-motor parameters, and further improve the accuracy of efficiency testing.

The resistance of an electric fan can be determined by measuring the resistance value. In order to measure the resistance value, we need to prepare a multimeter. First, adjust the selection knob of the resistance meter to the resistance measurement position.

Then, connect the test pen of the resistance meter to both ends of the resistor. It is important to note that before measuring the resistor, the resistor should be uncharged, otherwise it will affect the accurate measurement of the resistor. Next, use our multimeter to measure the resistance value.

The resistance value of an electric fan resistor usually changes due to loss or other reasons. When the resistance value of the electric fan resistor increases, it will cause more heat to be generated when the current flows through the resistor, which will eventually cause the resistor to overheat and burn out. Therefore, it is very important to measure the resistance value of the resistor.

If the resistance measurement is higher than the resistance value specification, it means that the fan resistance is damaged and needs to be replaced with a new one.

In addition to measuring the resistance value, we can also check the quality of the resistance of the electric fan by other ways through bridge die grinding. For example, we can check for physical damage by looking at the appearance of the resistor, or check for signs of burnout or overheating by smelling the resistor. Of course, before performing any inspection or repair, please be sure to disconnect the power supply and take the necessary safety measures to ensure personal safety.

In conclusion, measuring resistance is a very simple and effective way to determine whether the resistance of an electric fan is good or bad. In addition to the measurement of the resistance value, we also need to pay attention to the appearance and smell of the resistance in order to evaluate the condition of the resistance of the electric fan more comprehensively. Finally, always make sure that safety measures are in place at all times and that you do so with caution!

Reply to Cassia No's post, z: h; ^u$ t$ u% j6 e6 d; n! s( v- ?0 g- @朋友, I am not talking about the degree of motor failure, but whether the quality of the DC motor can be measured by the resistance method.

It is the DC resistance value of the winding wire (copper or aluminum wire) used in the winding of the motor.

r= l s (where is the resistivity of the conductor, l is the length of the conductor, and s is the cross-sectional area of the conductor).

As shown in the figure, there is a diagram of the internal winding structure of a fan motor, and the resistance between the various colored leads is measured with a multimeter. This is called the winding resistance. Experienced masters can also judge its quality based on the value of the resistance.